Stevia rebaudiana

Propagation

No self-incompatibility was noted in clones of rebaudiana. Self and cross-pollination by hand gave 93% and 92% germination.[1] Previous studies, however, have indicated the potential for self-incompatibility mechanisms.[2]

Insect pollination gave 78% germination. Pollination by the wind from circulation fans gave 68% germination. Control plants without significant air currents or pollinators had only 36% germination. No indication of pollination of the mother plant was given.[1]

Stem cuttings are a common propagation method.[3]

Propagation of the same base genotypes from seeds, stem cuttings, and micropropagation shows no statistical difference in growth or chemical composition.[4]

[5] [6] [4]

Germination

Stevia suffers from poor germination. Maximal germination is limited by seed viability. In seeds with a viability of 69% (tetrazolium test), 67% germination with a mean germination time of 3.5 days was seen with 14-hour red light illumination at 420 lux in peat-filled trays with clear domes. The control group not subject to this light schedule only showed 14% germination with a mean germination time of 12 days.[7]

Seed color and weight are good indicators of viability. Black seeds with an average weight of 300mg/1000 seeds had a germination rate of 77%. Tan seeds with an average weight of 178 mg/1000 seeds had a germination rate of 8.3%. Light exposure increased the germination of dark seeds by a further 10% but did not affect tan seeds.positive photoblasty[1]

In contrast, another study noted no significant correlation between seed weight and germination percentage. Similarly, some accessions displayed a trend toward negative photoblasty though the data is heterogeneous between treatments of the same accession.[8]

Light increases the proportion of normal development.[9]

Germination is highest at 20-25°C in the light. Significant reductions were noted at 15 and 30°C.[3]

In another study, germination at 25°C was robust and uniform with 99% of viable seeds germinating by 5.5 days (90% total germination). Mother plants were kept in a greenhouse, but there was no mention of the pollination procedure.[10]

Removal of the pappus results in abnormal development of the seedling.[8]

Seed development can be affected by local climate conditions. Flowers that were subjected to heavy rainfall and low temperatures in the late season had three-fold greater empty seeds compared to early flowers.[8]

Germination rate varies considerably between accessions of rebaudiana grown in the same conditions (18%-73%). The germination rate variance is largely attributed to accession, but the mean germination time is mostly attributable to pre-chilling treatment.[8]

Seed produced in the controlled climate of greenhouses has a higher germination rate than field-grown seeds.[9]

[9]

[11]

Vegetative

[12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25]./ [26] [27]

In-Vitro

[28] [29] [30] [31]

[32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42] [43] [44] [45] [46] [47] [48] [31] [49] [50] [51] [52]

Cultivation

[66] [56]

[67] [68] [69] [70] [5] [71] [72] [65]

Harvest

[32] [73] [74] [75] [61] [76] [77] [78] [79] [80] [56] [81] [82] [83]

Yield

Rebaudiana yield is significantly impacted by growing conditions, especially irrigation, and harvest time. Rebaudiana is tolerant of dry conditions, however, yields are significantly reduced without compensatory irrigation. Even in its native range, irrigation can more than double the yield.[69]

Rebaudiana favors early transplant times.[59]

Stevioside concentration is unaffected by plant spacing or transplant date. Any increase in total yield is by biomass accumulation only.[59] In a meta-analysis, the highest yield was found to be in the 8-12 plants per square meter range. However, the data only spanned 2-15 plants/m2 and the curve fit was exceedingly low (R2=0.17). Furthermore, the yield data was from fresh biomass, confounding the (more useful) dry yield per density determination.[85]

One possible reason for the minimal planting density is disease resistance. Rebaudiana seems to be sensitive to moisture-promoted pests. A thinner planting density allows more air circulation, reducing the effect of these pathogens.[16]

Secondary sources suggest that experiments of 4-40 plants per square meter were conducted by Katayama et al. in 1976 (primary source not located). The cited study found 8-11 plants per m2 had the highest yield for the first year.[2]

[86] [67] [68] [70] [87] [88] [89] [90] [91] [53] [71] [92] [93] [94] [95] [96] [97] [54] [98] [99] [100] [84] [55] [101] [61] [102] [103] [104] [57] [105] [106] [107] [108] [109] [110] [111] [39] [112] [113] [114] [115] [116] [117] [118] [119] [120] [121] [122] [123] [124] [62] [125] [126] [127] [78] [128] [129] [130] [131] [132] [133] [134] [80] [135] [136] [137] [138] [139] [56] [140] [141] [60] [59] [142] [143] [144] [145] [146] [147] [148] [82] [83] [149] [150] [151] [152]

Soilless

[86] [153]

Soil

[68] [70] [87] [88] [90] [74] [91] [53] [92] [93]

Fertilization

[86] [154] [155] [88] [90] [91] [71] [156] [92] [157] [93] [158] [159] [100] [160] [57] [105] [106] [110] [161] [162] [118] [119] [121] [163] [164] [129] [165] [132] [134] [138] [144] [166] [167] [147] [149] [151] [168]

Temperature

Rebaudiana is a tender perennial.

Only 16 out of 96 genotypes survived the winter in Toulouse, France (43°36’N, 1°24’E).[65] The average low temperature in winter is 2°C (January mean 6°C, high 10°C). Similar climate conditions are seen in Davis, California where the plants are said to overwinter and can be grown as a perennial. Only 18 out of 200 genotypes survived the winter. One genotype retained green branches through the winter.[27]

Early frosts can terminate seed development.[27]

Lighting

Flowering is triggered by a photoperiod of less than ~13 hours.

[169] [170] [171] [120] [62] [172] [173] [3] [174] [175]

Pests

[53] [176] [92]

Ecology

[154] [90] [156] [157] [176] [92]

Morphology

[177] [178] [179] [176] [93] [169] [180] [34] [181] [182] [183] [184] [185] [186] [53]

Roots

Stem

Leaves

[187]

Inflorescence

Compound inflorescence; cyme of cryombs; five white tubular flowers.[188]

Achene fruit. Feathery pappus.[188]

Seeds

The average seed weight is 200-300mg per 1000 seeds. Tan-colored seeds (likely nonviable) weigh about half as much as their dark-colored counterparts.[7][1][8]

[9] [170] [189] [190] [79] [44] [191] [173] [142] [3] [192]

Phytochemistry

Rebaudiana is cultivated for steviol glycosides, derived from the mevalonic pathway. Stevioside and rebaudioside A are the most common glycosides with the latter having the greatest public appeal by taste test.[2] The establishment of a rebaudiana cultivation market should focus on the production of elite varieties producing high rebaudioside A fraction.[65]

In a study of 96 genotypes, genotype, plant age, and planting year were significantly correlated with steviol glycosides.[65]

Steviol glycosides were not significantly affected by the removal of apical buds (pinching) to promote branching.[123]

[193] [187] [194]

[86] [153] [32] [67] [70] [155] [71]

Infraspecific Variation

[87] [89]

Biosynthesis

[178] [195] [157] [196] [176] [93]

Distribution

[74] [177]

Timecourse

[197] [91] [177] [179] [65]

Improvement

Total glycoside concentration between seedling and harvest stages is uncorrelated, making early selection useless.[2]

Stevioside content and composition have high genotypic variability.[65]

A high yield of rebaudioside A should be a primary target. Cold and disease tolerance are also a priority.

[89] [65]

Identification

Stevioside production is highly heritable (h^2^ = 83).[198]

Inheritance

Methods

[67] [195]

History & Society

Work Log

17 Feb 2023

Oops. Should have started seeds earlier. Oh wel.

Target 100g of dry leaf in a year. 7.5g per plant. 13 plants. I also want seeds, so double that to 26 plants. Call it 36 plants to split 3 sources into 6-cell flats.

10 Jan 2023

One or two months seems like the amount of time for stevia seedlings to establish for field transplantation. They also favor early transplanting, so I think I should get started germinating in the next couple of weeks.

An early frost and a late start could be the reason why my stevia seeds were not viable last season.

09 Jan 2023

Almost every reference uses the recommendation of 8-11 plants per square meter. Even studies on plant density do not plant at much higher/lower. I think this is based on a 1976 report from the I.S.U. company in Japan. The meta-reviews have terrible curve fitting.

Several density comparison papers find the highest productivity at the highest density tested. I think it is worth investigating the 15-25 plants per square meter range, especially for my region which could negate perennial plantings. Excessive water consumption might be a limiting factor for growth at this density. Though, overall, a higher density is better for water conservation.

08 Jan 2023

Preparing for the 2023 growing season

Target: 1 sugar cube equivalent per day

• 1 sugar cube = 4g sugar
• 1g dry stevia leaves = 15g sugar ref
• need about 0.25g stevia leaf per day
• about 100g per year

Stevia sweeteners are highest just before the flowering stage. I want to produce seeds, so seed-bearing plants will need to be grown in addition to leaf-bearing plants.

22 Mar 2022

Seeds 3,4,5 from EFN have germinated. So far nothing from TWF has germinated.

Since I am getting such good germination from EFN, I have started a “control” group of 12 seeds in a petri dish. The dish is placed in the closet under white LED illumination (4000k; ~4000 lux-app measured) for 14-16 hours per day.

21 Mar 2022

Two seeds have already germinated!

The light system only pulls 1.6 watts according to a kill-a-watt meter. If we assume 50 lumens per watt with 80% converter efficiency and an 8-inch x 4-inch box, that comes out to 290 lux.

20 Mar 2022

So the LEDs I used might be far-red, not red: They might be doing more harm than good. I bought the ELDs a long time ago for experiments with photobiomodulation (transcranial illumination). Both red and near-IR are common so I don’t know which I chose. The chips were not labeled.

19 Mar 2022

Started 24 seeds. Selected 12 dark seeds each from EFN and TWF. No pretreatment. Sowed straight to Petri dishes.

Placed in a make-shift red-light chamber for >14-hr photoperiod. The illumination level is set at around 5,000 lux as measured by a phone app (likely inaccurate especially with monochromatic light).

This is based on one instance of 420 lux being used to enhance germination.[7] I figured I would increase it to the typical light intensities used for grow lights.

15 Mar 2022

Likely greenhouse-grown, hand-pollinated plants will produce the greatest number of viable seeds. Selection for early seeding varieties will promote germination.

Bibliography

1. Goettemoeller, Jeffrey and Ching, Alejandro, Seed Germination in Stevia Rebaudiana, Perspectives on New Crops and New Uses, pp. 510--511, 1999. url: https://www.hort.purdue.edu/newcrop/proceedings1999/v4-510.html. Abstract
   Stevia (Stevia rebaudiana Bertoni, Asteraceae) is a non-caloric natural-source alternative to artificially produced sugar substitutes. The sweet compounds pass through the digestive process without chemically breaking down, making stevia safe for those who need to control their blood sugar level (Strauss 1995). There have been no reports to date of adverse effects from the use of stevia products by humans (Brandle and Rosa 1992). Shock (1982) reported that stevia contains eight glucoside compounds, each featuring a three-carbon-ring central structure. Stevioside is the most abundant glucoside produced. An extract of one or more of these compounds may be up to 300 times sweeter than sugar (Duke 1993). Preliminary trials at Davis, California indicate that stevia could produce a sweetener equivalent to 10 t/ha of sucrose (Shock 1982). The Guarani Indians of Paraguay, where stevia originates, have used it for centuries as a sweetener for maté tea (Brandle and Rosa 1992). Since the 1970s, stevia extracts have been widely used in many countries as a sugar substitute. In Japan, for instance, stevia extracts account for about 5.6\% of the sweetener market (Strauss 1995). Stevia usage in the United States is limited at this time because the Food and Drug Administration does not allow its use as a sweetener in manufactured and processed food products. In 1991, the FDA banned stevia, claiming it was an “unsafe food additive.” The FDA now allows the sale of stevia, but only as a nutritional supplement (Whitaker 1995).
2. Brandle, J. E. and Starratt, A. N. and Gijzen, M., Stevia Rebaudiana: Its Agricultural, Biological, and Chemical Properties, Canadian Journal of Plant Science, vol. 78, no. 4, pp. 527--536, October 1998. doi: 10.4141/P97-114. Abstract
   Stevia rebaudiana is a member of the Compositae, native to Paraguay. It produces a number of high-potency low-calorie sweeteners in its leaf tissue. The sweeteners are diterpene glycosides and range between 30 and 320 times sweeter than sugar. Increasing consumer interest in natural food ingredients means that products like stevia sweeteners will be sub- ject to increasing demand. Such demand will need to be supported by a modern mechanised production system. The purpose of this review is to summarize the existing agricultural, chemical and biochemical literature to provide a baseline for new research.
3. Uçar, Esra and Özyiğit, Yaşar and Turgut, Kenan, The Effects of Light and Temperature on Germination of Stevia (Stevia Rebaudiana BERT.) Seeds, Türkiye Tarımsal Araştırmalar Dergisi, vol. 3, no. 1, March 2016. doi: 10.19159/tutad.76528. Abstract
   The Stevia rebaudiana (Bert.) Bertoni is a perennial herbaceous plant and belongs to family of Asteraceae (Compositae). The contents of S. rebaudiana (Bert.) Bertoni consist mainly non-caloric stevioside and rebaudioside A sweeteners. Low seed germination is an important problem in stevia cultivation. Therefore in this study, the effects of light and temperature on germination performance of stevia seeds were studied. Stevia rebaudiana seeds were treated with two lights (light/darkness) and four different temperatures (15 ºC, 20 ºC, 25 ºC, 30 ºC). For each treatment, 50 seeds were counted and placed into petri dishes. Experiments were conducted as a randomized complete design method with three replicates. Germination was started within 6 to 10 days depending on the treatments. The highest seed germination rate (71\%) was observed in darkness/25 ºC temperature and followed by darkness/20 ºC (68\%) and light/25 ºC (67\%). On the other hand, the lowest seed germination rate (31\%) was obtained from 15 ºC in both light and dark conditions and followed by darkness/30 ºC (43\%) and light/30 ºC (49\%). The results showed that lower (15 ºC) and higher (30 ºC) temperatures significantly decreased the germination rates of stevia independently from the light treatments.
4. Tamura, Yukiyoshi and Nakamura, Shigeharu and Fukui, Hiroshi and Tabata, Mamoru, Comparison of Stevia Plants Grown from Seeds, Cuttings and Stem-Tip Cultures for Growth and Sweet Diterpene Glucosides, Plant Cell Reports, vol. 3, no. 5, pp. 180--182, October 1984. doi: 10.1007/BF00270194. Abstract
   The growth and sweet diterpene glucosides of Stevia plants propagated by stem-tip cultures were compared with those of the control plants propagated by seeds. There was no significant difference between the two groups both in growth and in chemical composition. As for the contents of sweet diterpene glucosides, however, the clonal plants showed significantly smaller variations than the sexually propagated plants; they were almost as homogeneous as the plants propagated by cuttings. These results suggest that the clonal propagation by stem-tip culture is an effective method of obtaining a population of uniform plants for the production of sweet diterpene glucosides.
5. {Ramírez-Jaramillo}, Genovevo and {Lozano-Contreras}, Mónica Guadalupe and {Moguel-Ordo\&ntilde}, Yolanda Beatriz and {ez} and {Aviles-Baeza}, Wilson I. and {Ramírez-Silva}, Jorge H., A Review of Research Results on Stevia Rebaudiana Bertoni in Yucatan Mexico from 2010 to 2017, Open Access Library Journal, vol. 8, no. 12, pp. 1--15, December 2021. doi: 10.4236/oalib.1108164. Abstract
   This paper integrates information on research studies carried out, in Stevia rebaudiana Bertoni, by the Southeast Regional Research Center (CIRSE) of the National Institute of Forestry, Agricultural and Livestock Research (INIFAP) in Mexico. Stevia is an ancient plant of Paraguayan origin with great potential to produce natural sweeteners. There is a constant demand at the national and international levels for this crop so new varieties adapted to different environments are required in order to reduce production costs, avoid dependence from abroad, improve yields and increase the acreage. The Mexican CIRSE has documented a series of innovations since 2010 in stevia such as: 1) studies of the productive potential, 2) production of seedlings with biological rooters, 3) population densities, 4) pre-emergence control of weeds, 5) fertilization doses, 6) materials better adapted to Mexican environment conditions and 7) evaluation of main stevia glycosides such as Stevioside and Rebaudioside-A among the most important. The main scientific findings are reported in this paper with the hope that stevia producers use it as a guide to improving their stevia production crop.
6. Midmore, David and Rank, Andrew H, A New Rural Industry – Stevia – to Replace Imported Sweetener, no. W02/022, pp. 56, August 2002. url: https://acquire.cqu.edu.au/articles/report/A_New_rural_industry_-_Stevia_-_to_replace_imported_chemical_sweeteners_a_report_for_the_Rural_Industries_Research_and_Development_Corporation/13425215. Abstract
   Stevia is a plant with carbohydrate-based compounds that are 200-300 sweeter than sugar. These compound, steviosides, can be extracted and used as alternative sweeteners to sugars, of particular benefit to diabetics and those wishing to reduce sugar intake for health reasons. A review of current literature, and visits to Japan and China were undertaken to determine the likely benefits or otherwise of establishing a stevia industry in Australia. While steviosides are not currently permitted as food additives in Australia, they are in China, Japan, Taiwan and Korea. During discussions with potential stakeholders in a stevia industry, it was determined to address the requirements by Food Standards Australia New Zealand (FSANZ – formerly ANZFA) for registration of stevia for use in the food industry, and to determine the economic feasibility of growing and processing stevia within Australia. These two sets of activity, which will be supported by industry, university and RIRDC funding, will draw heavily upon the literature review prepared, the contacts made during the overseas trips and on the reports that support use of steviosides in the aforementioned countries.
7. Abdullateef, Raji A. and bin Osman, Mohamad and bint Zainuddin, Zarina, Acclimatized Apparatus Enhanced Seed Germination in Stevia Rebaudiana Bertoni, International Journal of Biology, vol. 7, no. 2, pp. p28, January 2015. doi: 10.5539/ijb.v7n2p28. Abstract
   Stevia rebaudiana bertoni produces sweet glycosides with zero calorie and has strong health and dietary implications. With these properties, it has the potential to substitute sugar. However, poor seed germination in this plant constitute obstacle towards large scale propagation, thereby causing plant materials to be scarce and costly. High percent seed germination could be induced via simulation of favorable climatic environment. Thus, new protocols and prototype tagged ‘seed germination apparatus’, inclusive of conducive factors, were developed. Additionally, Seed viability level was also tested using 1 \% tetrazolium chloride. ANOVA revealed significant differences between treatments at p {$<$} 0.05. The apparatus influenced high yield of about 67 \% seed germination, while the viability test showed 69 \% viable seeds. Acclimatized condition, owing to innovated seed germination apparatus, showed high impact on seed germination in stevia.
8. Macchia, Mario and Andolfi, Laura and Ceccarini, Lucia and Angelini, Luciana G., Effects of Temperature, Light and Pre-Chilling on Seed Germination of Stevia Rebaudiana (Bertoni) Bertoni Accessions, Italian Journal of Agronomy, vol. 2, no. 1, pp. 55, March 2007. doi: 10.4081/ija.2007.55. Abstract
   Stevia rebaudiana (Bertoni) Bertoni is a perennial shrub of the Asteraceae family native to Paraguay and Brazil where it has been used for several years as a sweetener. It is a short-day species, with a critical light requirement for flowering of roughly 13 hours. In plants whose biological cycle is strongly photoperiod-dependent, latitude is one of the major factors influencing reproduction. Late flowering may adversely affect seed production if this occurs during a season that is unfavorable to pollination. At Italian latitudes, this species often gives scanty seed production, with low germination rate and poor germination energy of seeds produced. In 2001 four accessions have been grown for seed production in a field plot experiment in Central Italy. The various accessions were found to exhibit noticeably different photoperiod requirements, which affected flowering time (from late August to the end of September) and consequently also the conditions of achene filling and ripening. Late flowering and seed ripening occurred during autumn season, unfavourable to complete seed formation, leading to an increase in the empty seed percentage recorded for each accession. Detailed germination trials were therefore undertaken using seeds collected from plants of the different accessions in order to assess the quality of the seeds produced. Various germination methods have been tested in a controlled environment adopting four different temperatures (20° C, 25° C constant temperature and 15/25° C, 20/30° C (16/8h) alternating temperature) in light or darkness with or without pre-chilling. Germination rates varied over an extensive range (germination percentage from 9 to 83\%), mainly due to the divergent specific characteristics of the material examined and the different treatments studied. At all temperatures tested, the most earlier accession, showed the higher germination percentages (54-83\%) while the latest accession was among those with the lowest germination values (9-44\%). Overall, at the constant temperatures assayed, pre-chilling gave a higher germination percentage as compared to no pre-chilling, while at alternating temperatures higher germination rates were obtained in the absence of pre-chilling. The great variability observed between accessions for photoperiodic requirement as well as in seed germinative characteristics was probably due to the fact that this species was not subjected to any genetic improvement program.
9. Pereira, Edilenia and Janeiro, Vanderly and Guedes, Terezinha and Pedroza Carneiro, José, Stevia Rebaudiana (Bert) Bertoni: Regression Models with Mixed Effects for Investigating Seed Germination Data, Acta Scientiarum Agronomy, vol. 41, January 2019. doi: 10.4025/actasciagron.v41i1.39609. Abstract
   We investigated regression models with mixed effects using generalized linear statistics to evaluate germination data from Stevia rebaudiana (Bert) Bertoni. Estimates and validation of statistical parameters were conducted using the “gamlss” package in the R software. Generalized linear mixed effects followed the binomial, the beta-binomial and the multinomial distribution with the logit link to explain data based on the following explanatory variables: seed germinator, plastic tray position on every tier of shelves, illuminance conditions (light and darkness) and seed lots. We did not find differences in proportional responses from seed germinators, but we did find differences in the illuminance conditions, plastic tray position on the tiers of shelves in the seed germinators and seed lots. The estimates of the generalized Akaike information criterion (GAIC), Akaike information criterion (AIC), global deviance (GD) and Bayesian information criterion of Schwarz (BIC) indicate similar goodness-of-fit for the binomial and beta-binomial models. All of the models indicate that the position of the germination tray on every tier of shelves and illuminance conditions affected the proportions of normal seedlings. The seed germination in the plastic tray on the uppermost position under fluorescent day light lamps had an effect on the proportion of normal seedlings of Stevia.
10. Takahashi, Luciana and Melges, Elena and Pedroza Carneiro, José, Germination Performance of Stevia Seeds under Different Temperatures, Revista Brasileira de Sementes, vol. 18, pp. 1--5, January 1996. url: https://www.researchgate.net/publication/266319456_Germination_performance_of_Stevia_seeds_under_different_temperatures. Abstract
    One experiment was carried out to verify the influence of 20, 25 and 30°C on the performance of seed germination of Stevia (Stevia rebaudiana (Bert.) Bertoni). Data sets from cumulative frequencies, at intervals of 12 hrs, were combined with the cumulative distribution of Weibull using three parameters. The best performance was verified at 25°C. The seeds required 101.36 hours to germinate 63.21\% of the maximum. The performance of the parameters of the cumulative distribution of Weibull was close to linearity in temperatures of 20 and 25°C and reasonably close to linearity in temperatures of 30°C. In this case, the parameter c was asymmetric and had high percentage of bias.
11. Kawatani, Toyhohiko and Kaneki, Yoshizo and Tanare, Takeshi, On the Cultivation of Kaa He-e ({\emph{Stevia Rebaudiana}} Bertoni), Japanese Journal of Tropical Agriculture, vol. 20, no. 3, pp. 137--142, 1977. doi: 10.11248/jsta1957.20.137. Abstract
    1) With a view to elucidating the germination of the seeds of Kaa He-e (Stevia rebaudiana Bertoni) with special reference to the optimum temperature and light sensitivity, the present studies were carried out by germination test with petri dishes using incubators, at the Tokyo University of Agriculture, mainly during a period from 1973 to 1976. Results obtained are summarized as follows:2) The optimum temperature for germination is 20°.3) Weak light sensitivity is found to be present at 25°-30°, the seeds proving to be a light germinator. The light sensitivity at 25°is rather stronger than that at 30°.4) The life duration of the seeds is about 3 years.5) By oversummering the viability of seed decreases remarkably. When the seeds are stored in unsealed wooden-boxes at room temperature for one year, about half of the viability is lost.6) When the seeds are stored in desiccators at room temperature in the dark, they maintain almost the same viability of seed for one year at the lowest as those freshly collected.
12. Galo, Elmer V., In Situ Clonal Propagation of Stevia (Stevia Rebaudiana, Bertoni) Using Hormones, American Journal of Plant Sciences, vol. 10, no. 10, pp. 1789, October 2019. doi: 10.4236/ajps.2019.1010126. Abstract
    The sweet taste of Stevia leaves makes it a potential substitute for table sugar which can be used to sweeten foods and beverages. However, the limited planting materials become a constrained to large production; hence the experiment aims to investigate the different part and methods of propagation for stevia specifically use of different rooting hormones. The experiment was laid out in 3 × 4 factorial arranged in Randomized Complete Block Design. It consists of 3 types of cutting (shoot tips, intermediate stem and basal stem part) and four kinds of commercial hormones (miracle gro, rootech gel, NAA and control). Results showed that the highest percentage survival of stevia was obtained from shoot tips (93.92\%) which differed statistically from those intermediate (91.00\%) and basal stem cuttings (85.51\%). On the other hand, basal stem cutting significantly has the lowest percent survival. Results revealed that shoot tip cuttings treated with Rootech Gel developed roots early (6.92 days), with most number of roots (13.70), longer roots (3.33 cm), and 96.38\% survival.
13. Bortoloso Pigatto, Guilherme and Nunes Gomes, Erik and De Cássia Tomasi, Jessica and Portes Ferriani, Aurea and Deschamps, Cícero and Bortoloso Pigatto, Guilherme and Nunes Gomes, Erik and De Cássia Tomasi, Jessica and Portes Ferriani, Aurea and Deschamps, Cícero, Effects of Indolebutyric Acid, Stem Cutting Positions and Substrates on the Vegetative Propagation of Stevia Rebaudiana Bertoni, Revista Colombiana de Ciencias Hortícolas, vol. 12, no. 1, pp. 202--211, April 2018. doi: 10.17584/rcch.2018v12i1.6631.
14. Khalil, Shahid Akbar and Zamir, Roshan and Ahmad, Nisar, Selection of Suitable Propagation Method for Consistent Plantlets Production in Stevia Rebaudiana (Bertoni), Saudi Journal of Biological Sciences, vol. 21, no. 6, pp. 566--573, December 2014. doi: 10.1016/j.sjbs.2014.02.005. Abstract
    Stevia rebaudiana (Bert.) is an emerging sugar alternative and anti-diabetic plant in Pakistan. That is why people did not know the exact time of propagation. The main objective of the present study was to establish feasible propagation methods for healthy biomass production. In the present study, seed germination, stem cuttings and micropropagation were investigated for higher productivity. Fresh seeds showed better germination (25.51–40\%) but lost viability after a few days of storage. In order to improve the germination percentage, seeds were irradiated with 2.5, 5.0, 7.5 and 10Gy gamma doses. But gamma irradiation did not show any significant change in seed germination. A great variation in survival of stem cutting was observed in each month of 2012. October and November were found the most suitable months for stem cutting survival (60\%). In order to enhance survival, stem cuttings were also dipped in different plant growth regulators (PGRs) solution. Only indole butyric acid (IBA; 1000ppm) treated cutting showed a higher survival (33\%) than control (11.1\%). Furthermore, simple and feasible indirect regeneration system was established from leaf explants. Best callus induction (84.6\%) was observed on MS-medium augmented with 6-benzyladenine (BA) and 2,4-dichlorophenoxyacetic acid (2,4-D; 2.0mgl−1). For the first time, we obtained the highest number of shoots (106) on a medium containing BA (1.5mgl−1) and gibberellic acid (GA3; 0.5mgl−1). Plantlets were successfully acclimatized in plastic pots. The current results preferred micropropagation (85\%) over seed germination (25.51–40\%) and stem cutting (60\%).
15. Khlebova, L. P. and Orazov, A. and Titova, A. M. and Pirogova, A. V., Adaptation to Ex Vitro Conditions of Stevia Rebaudiana (Bertoni) Hemsl. Regenerants, Ukrainian Journal of Ecology, vol. 9, no. 3, pp. 376--380, 2019. doi: 10.15421/2019_110. Abstract
    Stevia rebaudiana (Bertoni) Hemsl. belongs to Asteraceae family and is of great importance for pharmaceutical and food industries. Stevioside obtained from the leaves of this plant is regarded as a valuable natural sweetener. Low seed fertility is one of the most important problems in stevia production. It multiplies almost exclusively in a vegetative way. Plant tissue culture is an efficient method for mass propagation of S. rebaudiana. We studied the effect of various concentrations of auxins on rooting stevia shoot cuttings under in vitro conditions. We found that adding 0.6-1.0 mg l-1 IBA or 0.2 mg l-1 IAA to the В5 medium is effective forrooting the shoot fragments of this species. The regenerants were adapted to ex vitro conditions for 3 weeks on a hydroponic setup filled with a solution of mineral salts according to the quarter-strength Murashige and Skoog (MS) basal medium modified by the content of KH2PO4 and NH4NO3. Using a triple concentration of KH2PO4 (510 mg l-1) during the first week of adaptation and a fullconcentration of NH4NO3 (1650 mg l-1) over the next 2 weeks ensures 100\% acclimatization of stevia regenerants to ex vitro conditions. The replacement of agar in the nutrient medium with a perlite-vermiculite mixture in the ratio of 1 : 3 stimulated the transition of regenerants to the photomyxotrophic type of nutrition. The use of a porous substrate provided a decrease in humidity inside the culture vessels, which led to forming both leaves with well-functioning stomata and a branched root system with root hairs. The stevia regenerants propagated in vitro on a porous substrate did not require special conditions for the ex vitro acclimatization. The yield of surviving plants in the greenhouse was 100\%.
16. Kiss, Annamária and Hájos, Mária Takácsné, Stevia (Stevia Rebaudiana B.) Yield in the Case of Different Production Technologies, Acta Agraria Debreceniensis, no. 72, pp. 71--77, May 2017. doi: 10.34101/actaagrar/72/1591. Abstract
    Stevia rebaudiana B. offers a natural alternative of sweetening, potential health promotion plant, and our country shows increased interest about cultivation in Hungary in addition to the neighboring European countries. The agricultural production system installation necessaryunderstanding of the needs of the plant, as well as exploring the agronomic potential. Field experiments were conducted in 2015 with the aim to highlight some of the technological production parameters and correlations between them. We have reviewed the most important agronomic factors, the spacing (50×50 cm and 33×33 cm), ground covering (agro-cloth covered and uncovered/ control), their vegetative growth (first-,second-order branch), herb yield and quality in effect.Based on empirical evidence, that the Hungarian climates also have the opportunity of 3 cuttings during a growing season, besides of early planting, optimal climatic conditions (in October didn’t reduce the daily minimum temperature below 0 °C, after cuttings the maximum interval values remain below 40 °C), and adequate water supply and crop protection facility. The 33×33 cm spacing evaporates more than 50×50 cm spacing, because of the dense population, the continuous canopy less able to breathe, so there are serious chances to the pathogen colonization.Based on the results of our research to the wider 50×50 cm spacing favorable appreciate the stevia optimal progress in terms of qualitative and quantitative parameters of the yield. The stevia yields produced in the Northern Great Plains field cultivation can produce similar results as stevia crop yields in warmer climates, where the primary crops. Our research experience suggest that there is a viable domestic stevia cultivation, developing the necessary technology is still growing further investigation justifies.
17. Smitha, G. R. and Umesha, K., Vegetative Propagation of Stevia [ Stevia Rebaudiana (Bertoni) Hemsl.] through Stem Cuttings, Journal of Tropical Agriculture, vol. 50, no. 1, pp. 72--75, October 2012. url: http://jtropag.kau.in/index.php/ojs2/article/view/271. Abstract
    Stevia rebaudiana (Bertoni) Hemsl. is a non-caloric bio-sweetener wherein seed propagation is difficult. Propagation of stevia through stem cuttings was evaluated under two environmental conditions (natural shade and greenhouse with intermittent mist) and four combinations of sand, soil, FYM, vermicompost, and coir dust, with growth regulator (IBA), bio-inoculants (Trichoderma viride), and cow’s urine treatments. Stem cuttings treated with T. viride, placed in soil, sand, and vermicompost rooting media (1:1:1) under greenhouse conditions recorded better shoot and root growth parameters, besides better field establishment (90\%), over other treatment combinations.
18. Arpita, Das and Mainak, Biswas and Nirmal, Mandal, An Economic Analysis of Stevia ( Stevia Rebaudiana Bert.) Cultivation through Stem Cutting and Tissue Culture Propagule in India, Trends in Agricultural Economics, vol. 3, April 2010. doi: 10.3923/tae.2010.216.222. Abstract
    The present study has been formulated to study the cost of cultivation of stevia to encourage the farmer regarding cultivation of this plant and also provide information regarding profitability of cultivation. Stevia become a potential and renewable raw material in the food market because the increase in the number of diabetic and health conscious individual boost up the international market of high quality stevia leaves which is a non-caloric natural sugar. Lack of information regarding the cost of cultivation of stevia specially in Indian context generate plenty of confusion with regard to cultivation of this plant and also about selection of the profitable propagating material. The present study thus concerned with calculating the cost of cultivation, return and cost benefit ratio to identify economic viability and technical feasibility of stevia cultivation through cutting and tissue culture propagated planting material. For this an experimental plot size of 100x100 m each was used for cultivation for 3 years with cutting and tissue cultured plantlets as propagating material. The cost of cultivation refers to the total expenses incurred in cultivating stevia, expressed on a per hectare basis and worked out using operation wise approach in both the cases for three years. Lastly benefit cost ratio was incurred which is the ratio of the present worth of gross costs and represents the economic viability of the two projects. From the two project it was revealed that fixed as well as variable cost was more in tissue culture plantlets propagated field but tissue cultured plants favour disease free clean cultivation with high foliage production as compared with cutting where disease and pest infection was severe. For this during three years of economic life total sales of dry stevia leaves was generate more income in tissue cultured propagule established fields than cutting propagated field. From the cost benefit ratio of the two projects it was clear that profit of the two projects was comparable with each other and was technically feasible and economically viable.
19. Salama, A. M. A., Morphological, Anatomical and Chemical Studies on Stevia Plant and Its Response to the Growth Regulators GA3 and IBA, 2012. url: https://agris.fao.org/search/en/records/64738cac68b4c299a3f83790. Abstract
    A field experiment was carried out at Giza Agricultural Research ýStation, during the two successive seasons 2007-08 and 2008-09 aiming ýto investigate the effect of two growth regulators GA3 and IBA with ýthree concentrations (0, 250 and 500 ppm), applied in single or double ýfoliar sprays on the botanical, yield and chemical characteristics of ýstevia (Stevia rebaudiana (Bertoni) Hemsl.) plants. In addition, a ýgreenhouse experiment, was carried out to study the effect of the ýplanting date (spring, summer and fall), cutting position (tip, mid and ýbasal) and IBA concentration (0,500 and 1000 ppm) on the success of ýstevia propagation by stem cuttings. The field experiment showed that ýGA3 induced significant promotion effect on all morphological traits ýý(plant height, number of branches/plant, leaves fresh and dry ýweights/plant, stem fresh and dry weights/plant and total dry weight of ýleaves over the four cuts (the yield)), while decreased flowering ýbranches percentage comparing with control. The effect of ýconcentration regardless of type of growth regulators, 500 ppm induced ýsignificant effects on the previous morphological traits. Also, the result ýexplained the role of number of sprays on promoting the vegetative ýgrowth,as plants sprays twice showed increases in all morphological ýtraits compared with theþ þsingle spray. Studying the anatomy, GA3 ýinduced different effects on the anatomical structure of the main stem ýand leaf of stevia according to the used concentration. The maximum ýreduction in stem diameter was observed with 500 ppm GA3 ýtreatments. It is observed that, both cortex and vascular tissues in GA3 ýtreated plants showed relatively decrease in thickness as compared with ýtheir respective control. Treatment with IBA, induced thicker stem due ýto increasing the thickness of all included tissues, especially phloem and ýxylem tissues and pith diameter, also there are positive effects on ýanatomical structure of the leaf blade. The highest stevioside percentage ýý(8.85\%) was in the 4thþ þý cut followed by the 1st cut of plants treated with ýdouble sprays of 500 ppm GA3. The interaction between the studied ýfactors proved that plants sprayed twice with 500 ppm IBA showed the ýhighest rebaudioside A (4.94\%). Non treated plants showed the highest ýcarbohydrates percentage (57.2\%) as compared with that of GA3 ýý(55.8\%) and IBA treatments (55.9\%). Maximum percentage of survival ýcuttings was obtained from basal cuttings treated with 1000 ppm IBA ýconcentration in spring (89.3\%) while the lowest value was obtained ýfrom tip cuttings with 0 ppm IBA in fall (20.3\%).ý
20. Padhiyar, Pooja K and Rathod, Mayuri C, Study of Various Combinations of Soil on Stevia Cuttings for Herbage Yield and Root Parameters, World Journal of Pharmaceutical Research, vol. 6, no. 17, pp. 792--797, 2017. url: https://wjpr.net/abstract_show/8620.
21. Abdullateef, Raji Akintunde and Osman, Mohamad, Effects of Stem Cutting Types, Position and Hormonal Factors on Rooting in Stevia Rebaudiana Bertoni, Journal of Agricultural Science, vol. 4, no. 1, pp. p49, November 2011. doi: 10.5539/jas.v4n1p49. Abstract
    Stevia rebaudiana Bertoni, a compositae, originated from Paraguay. It is propagated by stem cuttings. Leaves’ glycosides are about 300 times sweeter than sugar and safe for diabetic patients. In Malaysia, techniques for stevia mass production are limited. Varieties MS012 and MS007 obtained from MARDI were studied. For each variety, cuttings made were: (i) young apical shoot (ii) old apical shoot and (iii) non apical shoot. They were treated with six concentrations of IBA ranging from 1.9 to 2.5mM, and were placed in micro cutting chambers with the control. Characters studied were: (i) number of days for rooting, and (ii) root number at emergence. Analysis of variance revealed there were significant differences between characters at probability level p {$<$} 0.05. Cuttings from young apical shoots of MS012 and MS007 rooted on 5th day with root number ranging from 2.8 to 13.8. IBA 2.3mM was optimal. Young apical cuttings of either variety treated with the IBA 2.3mM were ideal.
22. Beemnet, Mengesha and Kassahun, Beemnet and Mekonnen, Solomon and Mekonnen, Solomon, Effect of Cutting Position and Rooting Hormone on Propagation Ability of Stevia (Stevia Rebaudiana Bertoni), The African Journal of Plant Science and Biotechnology ©2012 Global Science Books, vol. 6, pp. 5--8, October 2011. Abstract
    To fill in existing information and knowledge gaps on asexual propagation of stevia (Stevia rebaudiana Bertoni), this experiment was conducted at the Wondo Genet Agricultural Research Center nursery site in a plastic chamber. The experiment consisted of two levels of cutting positions (top and middle) and three levels of rooting hormones (zero hormone, 0.2\% indole-3-butyric acid (IBA) and 0.4\% 1-naphthalene acetic acid (NAA)). The experiment was laid out in a 3×2 factorial arrangement in a randomized complete block design with three replications. Data on leaf number/plant, survival count and rate were recorded and analyzed. Mean squares from analysis of variance revealed the existence of a very highly significant influence (P {$<$} 0.001) of cutting position on leaf number and survival rate. The application of rooting hormone exerted a significant influence (P {$<$} 0.05) on survival rate only. Interaction effect of cutting position and hormone application did not exert an influence (P {$>$} 0.05) on the parameters considered. Higher but statistically similar survival rate were recorded for the control and the 0.2\% IBA treatment whereas the lowest values were recorded for the 0.4\% NAA treatment. Top cuttings demonstrated significantly more leaves (eight) and survival rates (80.18\%) and showed a 46.78 and 28.49\% increase in leaf number and survival rate compared to middle cuttings. Therefore, it is recommended that the top part be used for the propagation of stevia. The application of rooting hormone might not necessarily be an economically sound option for vegetative propagation.
23. Lee, J. I. and Kang, K. H. and Lee, E. U., Studies on new sweetening resource plant Stevia (Stevia rebaudiana Bertoni) in Korea. I. Effects of transplanting-date shifting by cutting and seeding dates on agronomic characteristics and dry leaf yields of Stevia, The Research reports of the Office of Rural Development. Crops, 1979. url: https://agris.fao.org/search/en/records/647121713c73b155c84953ee. Abstract
    AGRICULTURAL SCIENCE AND TECHNOLOGY INFORMATION
24. Osman, Mohamad and Samsudin, Nur Syamimi and Faruq, Golam and Nezhadahmadi, Arash, Factors Affecting Microcuttings of {\emph{Stevia}} Using a Mist-Chamber Propagation Box, The Scientific World Journal, vol. 2013, pp. e940201, December 2013. doi: 10.1155/2013/940201. Abstract
    Stevia rebaudiana Bertoni is a member of Compositae family. Stevia plant has zero calorie content and its leaves are estimated to be 300 times sweeter than sugar. This plant is believed to be the most ideal substitute for sugar and important to assist in medicinal value especially for diabetic patients. In this study, microcutting techniques using a mist-chamber propagation box were used as it was beneficial for propagation of Stevia and gave genetic uniformity to the plant. The effects of different treatments on root stimulation of Stevia in microcuttings technique were evaluated. Treatments studied were different sizes of shoot cuttings, plant growth regulators, lights, and shades. Data logger was used to record the mean value of humidity ({$>$}90\% RH), light intensity (673–2045\,lx), and temperature (28.6–30.1°C) inside the mist-chamber propagation box. From analysis of variance, there were significant differences between varieties and treatments in parameters studied ( ). For the size of shoot cuttings treatment, 6 nodes cuttings were observed to increase root number. As compared to control, shoot cuttings treated with indole butyric acid (IBA) had better performance regarding root length. Yellow light and 50\% shade treatments showed higher root and leaf number and these conditions can be considered as crucial for potential propagation of Stevia.
25. Rashwan, Basma R. A. and {Reem M. Abd-El Raouf} and {Nagwa R. Ahmed} and {H. Ferweez}, Efficacy of K-Humate, Compost and Biofertilizer Application as Well as Cutting Number on Yield and Quality of Stevia (Stevia rebaudianaBertoni) as Natural Sweetener, Assiut Journal of Agricultural Sciences, vol. 48, no. 1-1, pp. 251--268, February 2017. doi: 10.21608/ajas.2016.3745. Abstract
    Stevioside is natural sweetener isolated from the leaves of plant stevia and it is up to 300 times sweetener than sucrose, since it is a sweetener with no caloric value and with proven non-toxic effect on human health. Steviol glycosides are used as a sweetener in many industrial foods, such as soft drinks or fruit juices. So, two field experiments were conducted at Mallawi Agricultural Research Station, El-Minia Governorate during 2014 and 2015 seasons to deduce the effect of different sources of nutrient, i.e. Control (80 kg N fed-1), K-humate + (40 kg N fed-1), biofertilizer +(40 kg N fed-1) and compost + (40 kg N fed-1)] and number of cutting , i.e. 1st , 2nd and 3rd cutting on yield and quality of stevia (Stevia rebaudianaBertoni) under Middle Egypt conditions. The obtained data pointed out that different sources of nutrient had a significant effect on plant height, fresh plant weight, dry plant weight, fresh leaves weight/plant, dry leaves weight/plant, N, P and K \% of stevia leaf, fresh biomass yield, dry biomass yield , fresh leaves yield, dry leaves yield and fresh stem yield, total stevioside \% (St \%), rebaudioside A\% (Rb\%), stevioside yield and rebaudioside A yield of stevia in two growing seasons. The studied cutting number of stevia had a significant influence on plant height, fresh plant weight, dry plant weight, fresh leaves weight/plant, dry leaves weight/plant, dry leaves weight: dry stem weight, P \% of stevia leaf, fresh biomass yield, dry biomass yield, fresh leaves yield, dry leaves yield and fresh stem yield and dry stem yield of stevia, rebaudioside A\%, total stevioside yield (kg/fed) and rebaudioside A yield (kg/fed) of stevia rebaudiana in two growing seasons. From the present study, it may be concluded that the application of compost at 2.0 ton/fed+(40 kg N fed-1) with 3rd cutting was the best treatment for improving the yield and quality of stevia (Stevia rebaudianaBertoni) and is advisable because it is achieved the highest value of rebaudioside A(102.80 kg/fed) of stevia. This helps in reducing the great gap in sugar production, which amounted to 0.7 million tons between production and sugar consumption at the national level production under the experimental conditions.
26. Tansı, Leyla Sezer and Samadpourrigani, Elnaz and Gedik, Selin, Effects of Different Plant Density and Cutting Times on Yield of Stevia under the Çukurova Conditions, International Journal of Secondary Metabolite, vol. 4, no. 3, Special Issue 2, pp. 355--358, December 2017. doi: 10.21448/ijsm.373822. Abstract
    Stevia ( Stevia rebaudiana Bertoni) is perennial shrub form plant belonging to Asteraceae. It is indigenous to Paraguay and Brazil. Stevia is a natural sweetening and it has using potential to diets of obesity patients with non-caloric specialty and treatment of diabetes with insulin secretagogue specialty. In this study, the effects of different planting spaces and two cutting times on yields of two-year old Stevia plant were investigated. The highest dry leaf yield (515.96 kg/da) was obtained from blooming stage, cuttings in spring and 30x60 cm planting density.
27. Shock, Clinton C., Rebaudi's Stevia: Natural Noncaloric Sweeteners, California Agriculture, pp. 5, September 1982. url: https://ucanr.edu/repository/view.cfm?i=i&search=&article=61878&mailer=yes. Abstract
    Leaves of Rebaudi’s stevia, a plant used historically in Paraguay as a sweetener and herbal remedy, contain compounds about 250 times as sweet as table sugar. Preliminary trials at the University of California, Davis, have shown that production of one of the compounds, stevioside, could be equivalent to the sweetening power of 28 tons per acre of sucrose. However, much needs to be learned about production. problems before the plant can be grown commercially. The plant, Stevia rebaudiana Bertoni, belongs to the eupatory tribe of the composite family and is native to northeastern Paraguay. It is related to other members of the genus found in the United States and in Central and South America. The chemicals of interest are stevioside, rebaudioside A, and at least six other sweet compounds that have glucoside groups attached to a three-carbon-ring central structure. Stevioside concentrations usually range between 3 and 10 percent of the leaf dry weight; rebaudioside A is less concentrated, ranging from 1 to 3 percent. Stevioside has also been of interest as a source of gibberellins, plant growth hormones, most of which are not available com- mercially. The glucoside groups are removed from stevioside to yield steviol. Modified or normal steviol has been placed in the growth medium of Gibberella fujikuroi mutants to produce several gibberellic acids. Gibberellic acid, GA, is known to occur naturally in stevia leaves but not in commercial quantities. Possible health risks from human consumption of the various compounds in Stevia rebaudiana are not well defined and are being studied by others.
28. Pande, S. S. and {e} and Gupta, Priyanka, Plant Tissue Culture of Stevia Rebaudiana (Bertoni): A Review, Journal of Pharmacognosy and Phytotherapy, vol. 5, no. 2, pp. 26--33, February 2013. doi: 10.5897/JPP13.0258. Abstract
    Plant tissue culture is a technique used forin vitroregeneration of plants. It relies on maintaining plant cells in aseptic conditions on a suitable nutrient medium. The culture can be sustained as a mass of undifferentiated cells for an extended period of time or regenerated into whole plants.Plant tissue culture techniques are also central to innovative areas of applied plant science, including plant biotechnology and agriculture. This review paper outlines the work done onStevia rebaudiana,a herbaceous perennial plant of the Asteraceae family. It is gaining lot of importance for the production of diterpene glycosides which are non-nutritive, non-toxic, high-potency sweeteners, and may substitute sucrose as well as other synthetic sweeteners, being 300 times sweeter than sucrose. The taxonomy, botanical description of the plant, its distribution and uses, are discussed in this paper. Various tissue culture methods to get mass propagation ofS. rebaudianaare reviewed. Key words:Stevia rebaudiana,asteraceae, tissue culture.
29. Kazmi, Abeer and Khan, Mubarak A. and Mohammad, Sher and Ali, Amir and Ali, Huma, Biotechnological Production of Natural Calorie Free Steviol Glycosides in Stevia Rebaudiana: An Update on Current Scenario, Current Biotechnology, vol. 8, no. 2, pp. 70--84, June 2019. doi: 10.2174/2211550108666191210100751. Abstract
    Stevia rebaudiana is a vital medicinal plant of the genus Stevia and family Asteraceae. It is commonly used as a natural sweetener plant and its products are 300 times sweeter than the commonly used sugarcane. The sweetening potential is due to the presence of calorie-free steviol glycosides (SGs). The plant species has been extensively profiled to identify steviol glycosides (SGs) with intensity sweetening properties. However, the limited production of plant material is not fulfilling the higher market demand worldwide. Researchers are working worldwide to enhance the production of important SGs through the intervention of different biotechnological approaches in S. rebaudiana. In this review, the research work conducted in the last twenty years, on the different aspects of biotechnology to enhance the production of SGs has been precisely reviewed. Biotechnological methods such as micropropagation, callus and cell cultures, elicitation and the metabolomics and transcriptomic elucidation of the biosynthetic metabolic pathways for the production of steviol glycosides have been concisely reviewed and discussed.
30. Basharat, Samra and Huang, Ziyang and Gong, Mengyue and Lv, Xueqin and Ahmed, Aqsa and Hussain, Iftikhar and Li, Jianghua and Du, Guocheng and Liu, Long, A Review on Current Conventional and Biotechnical Approaches to Enhance Biosynthesis of Steviol Glycosides in Stevia Rebaudiana, Chinese Journal of Chemical Engineering, vol. 30, pp. 92--104, February 2021. doi: 10.1016/j.cjche.2020.10.018. Abstract
    Stevia rebaudiana Bertoni is commonly called stevia and mostly found in the north east regions of South America. It is an herbaceous and shrubby plant belonging to the Asteraceae family. Stevia is considered as a natural sweetener and a commercially important plant worldwide. The leaves of S. rebaudiana contain steviol glycosides (SGs) which are highly potent and non-caloric sweeteners. The sweetening property of S. rebaudiana is contributed to the presence of these high potency, calorie free steviol glycosides. SGs are considerably suitable for replacing sucrose and other artificial sweetening agents which are used in different industries and pharmaceuticals. SGs amount in the plant mostly varies from 8\% to 10\%, and the enhancement of SGs is always in demand. These glycosides have the potential to become healthier alternatives to other table sugars for having desirable taste and zero calories. SGs are almost 300 times sweeter than sucrose. Being used as alternative sugar intensifier the commercial value of this plant in biopharmaceutical, food and beverages industries and in international market is increasing day by day. SGs have made stevia an important part of the medicinal world as well as the food and beverage industry, but the limited production of plant material is not fulfilling the higher global market demand. Therefore, researchers are working worldwide to increase the production of important SGs through the intercession of different biotechnological approaches in S. rebaudiana. This review aims to describe the emerging biotechnological strategies and approaches to understand, stimulate and enhance biosynthesis of secondary metabolites in stevia. Conventional and biotechnological methods for the production of steviol glycosides have been briefly reviewed and discussed.
31. Srivastava, Vartika and Chaturvedi, Rakhi, An Interdisciplinary Approach towards Sustainable and Higher Steviol Glycoside Production from in Vitro Cultures of Stevia Rebaudiana, Journal of Biotechnology, vol. 358, pp. 76--91, November 2022. doi: 10.1016/j.jbiotec.2022.08.018. Abstract
    Stevia rebaudiana is one of the vastly acclaimed commercial plant in the world and belongs to Asteraceae family. The exclusive advantage of Stevia over artificial sweeteners is impeccable and targets its potentiality to the presence of diterpene glycosides. Moreover, the flaunting sweetness of steviol glycosides with associated medicinal benefits, turns the plant to be one of the most economic assets, globally. As compared to vegetative propagation through stem-cuttings, plant tissue culture is the most suitable approach in obtaining true-to-type plants of superior quality. During last few decades, significant in vitro propagation methods have been developed and still the research is ongoing. The present review discusses the tissue culture perspectives of S. rebaudiana, primarily focusing on the mineral nutrition, growth regulators and other accessory factors, motioning the optimum growth and development of the plant. Another crucial aspect is the generation of sweeter varieties in order to reduce the bitter-off taste, which is noticed after the consumption of the leaves. The in vitro cultures pose an efficient alternative system for production of steviol glycosides, with higher rebaudioside(s) content. Moreover, the review also covers the recent approaches pertaining to scale-up studies and genome editing perspectives.
32. Kaur, Ramandeep and Manchanda, Pooja and Sidhu, Gurupkar Singh, Optimization of Extraction of Bioactive Phenolics and Their Antioxidant Potential from Callus and Leaf Extracts of Stevia Rebaudiana Bertoni, Journal of Food Measurement and Characterization, vol. 16, no. 1, pp. 461--470, February 2022. doi: 10.1007/s11694-021-01176-2. Abstract
    The present study was intended to investigate total phenolic content (TPC), total flavonoid content (TFC) and antioxidant potential in terms of radical scavenging activity (RSA) of organic solvent extracts from callus and leaves of Stevia rebaudiana Bertoni, which is very well known for its extraordinary sweetening properties. MS medium\,+\,2, 4-D (4~mg~L−1)\,+\,Kin (0.5~mg~L−1) was found to be the best medium for callus induction of stevia. The extracts from callus and leaves were prepared by ultrasonic extraction using different concentrations of ethanol:water i.e. 25, 50 and 75\% ethanol in water at different temperatures (30, 50 and 70~°C) and extraction times (10, 20 and 30~min). Maximum amounts of TPC, TFC and RSA (dependent response variables) were optimized by response surface methodology to study the effects of individual factors i.e. independent variables (ethanol:water ratio, ultrasonic temperature and time) and their mutual interactions on the values of above said responses. To the best of our knowledge, this is the first report involving optimization studies using these independent and dependent variables form extracts of stevia. On investigation of 3D surface plots, ethanol:water ratio as extraction solvent was found to be the most important factor in obtaining maximum TPC and TFC whereas ultrasonic temperature while extraction was observed as the determining factor for RSA. It was concluded that callus and leaves of S. rebaudiana possess enormous potential for their incorporation into dietary supplements. They can also be recommended as sugar-free and antioxidant functional ingredients in food products especially designed for diabetic people.
33. Ahmed, M B and Salahin, M and Karim, R and Razvy, M A and Hannan, M M and Sultana, R and Hossain, M and Islam, R, An Efficient Method for in Vitro Clonal Propagation of a Newly Introduced Sweetener Plant (Stevia Rebaudiana Bertoni.) in Bangladesh, pp. 6, 2007. Abstract
    Shootlets were regenerated from nodal explants of Stevia rebaudiana Bertoni through axillary shoot proliferation. The induction of multiple shoots from nodal segments was the highest in MS medium supplemented with 1.5 mg l 1 BA + 0.5 mg l 1 Kn. For rooting different concentrations of IBA, NAA and IAA were used and highest rooting percentage (97.66\%) was recorded on MS medium with 0.1 mg l 1 IAA. The rooted plantlets were hardened and successfully established in soil.
34. Akbari, F. and Arminian, A. and Kahrizi, D. and Fazeli, A., Effect of Nitrogen Sources on Some Morphological Characteristics of in Vitro Stevia Rebaudiana Bertoni, Cellular and Molecular Biology, vol. 63, no. 2, pp. 107--111, February 2017. doi: 10.14715/cmb/2017.63.2.17. Abstract
    Stevia rebaudiana Bertoni belongs to Asteraceae family that leaves 200-300 times sweeter than sugar. Low seed fertility is one of the most important problems in Stevia production. So, Plant tissue culture is an efficient method for mass propagation of Stevia. In this research, we studied the effect of various concentrations of nitrogen on some morphological traits of stevia under in vitro conditions. We used axillary nodes as explants and they were cultured on Murashige and Skoog (MS) medium containing inorganic nitrogen sources i.e. NH4NO3(0, 825 and 1650 mg/l), KNO3(0, 950 and 1900 mg/l) were observed. The cultures were kept for 4 weeks at a temperature of 25±2°C with a photoperiod of 16/8 hour low light/dark each day. Maximum shoot length (89.33 mm), dry weight of plants (0.10 mg) and leaf fresh weight (0.42 mg) was observed on MS medium with 1650 mg/l NH4NO3 and 950 mg/l KNO3. Minimum shoot length (6.13 mm), root length (6.60 mm), leaf number (4.26), leaf dry weight (0.01 mg), leaf fresh weight (0.05 mg), total dry and fresh weight (0.02 and 0.15 mg) and growth rate was observed on a MS medium without nitrogen sources. Moreover, presence of nitrogen sources increases both shooting and rooting in Stevia rebaudiana Bertoni.
35. Anbazhagan, M. and Kalpana, M. and Rajendran, R. and Natarajan, V. and Dhanavel, D., In Vitro Production of Stevia Rebaudiana Bertoni, Emirates Journal of Food and Agriculture, pp. 216--222, 2010. doi: 10.9755/ejfa.v22i3.4891. Abstract
    Experiments were conducted for the standardization of in vitro culture technique for the mass propagation of Stevia rebaudiana, a medicinally important, zero-calorie value, sweet tasted and an antidiabetic herb. Shoot tip, nodal segment and leaf were used as explants and they were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of BA, Kn and IAA both in individual and in combined form for shoot inductions and the best results were obtained from MS medium supplemented with BA+ IAA at the concentrations of 1.0 mg/l and 0.5 mg/l respectively. Among the explants used, shoot tip stood first in inducing shoot development. Best root formation of in vitro developed shoots could be achieved on half-strength Nitsch (N6) medium supplemented with IAA at concentration 1.0 mg/l. The in vitro developed plantlets were transferred to pot and they were grown in greenhouse for hardening and finally they were planted in the open filed. Around 82\% of plants were successfully established in natural field condition.
36. Barroso, Marisa and Goes, Hugo and Rodrigues, M. A. and Arrobas, Margarida and Pedro, Luís G. and Sousa, Maria João, Stevia Rebaudiana: A Study in the Volatiles Profile from Plants Grown in the Field in the Greenhouse and Micropropagated in Vitro, 1st European Conference of Post graduate Horticulture Scientists, pp. 16--16, 2016. url: https://bibliotecadigital.ipb.pt/handle/10198/15574. Abstract
    Stevia rebaudiana Bertoni leaves are natural sources of steviol glycosides, which are used commercially for sweetening and flavouring foods and beverages. Steviol glycosides are natural sweeteners constituting an alternative to synthetic compounds like cyclamates or aspartame. S. rebaudiana has been produced mainly for its stevioside compounds but it contains other metabolites with potential therapeutic benefits such as alkaloids, hydroxycinnamic acids, oligosaccharides or essential oils. The chemical profile of samples development by micropropagation or in green house or in field conditions, should be characterized to ensure the quality of the samples supplied by Stevia producers. Multiplication rate and fresh weight were determined for plants micropropagated in two different culture media (medium A - Murashige and Skoog (MS) without hormones and sucrose), (medium B - MS with 0.5 mg.L-1 of kinetin and 20 g.L-1of sucrose). Apart from spontaneous rooting rate determination, induction of plant rooting by auxin shock, using indole-3-butyric acid (IBA) (2 mg.mL-1), was also evaluated. Acclimatization in greenhouse was performed with hydro atomization nozzles working every 10 minutes. Plants on the field were fertilized by a nutrient solution with N, P2O5, K2O and B. The essential oil yield was determined for plants in all conditions (in vitro, greenhouse, field) using a Clevenger-type apparatus. Volatiles were isolated using a Likens-Nickerson apparatus and analyzed by GCMS. The in vitro multiplication rate was 300\% per month and the fresh weight after a 4 week subculture was 0.9 g. Spontaneous rooting rate was less than 4\% after 4 months but induced rooting achieved 30\% of plants with developed root system after 1 week and 70\% after 2 weeks. Acclimatization rate was 100\% after 2 weeks. The essential oil yield was {$<$}0.06\% for all samples. Volatiles identification revealed identical composition in all samples, with α-pinene (11-31\%), bicyclogermacrene (5‑19\%), trans-β-farnesene (7-15\%), β-elemene (6-10\%) and β-caryophyllene (3-10\%) as major compounds. Quantitative differences were noteworthy.
37. Blinstrubienė, Aušra and Burbulis, Natalija and Juškevičiūtė, Neringa and Vaitkevičienė, Nijolė and Žūkienė, Rasa, Effect of Growth Regulators on Stevia Rebaudiana Bertoni Callus Genesis and Influence of Auxin and Proline to Steviol Glycosides, Phenols, Flavonoids Accumulation, and Antioxidant Activity In Vitro, Molecules, vol. 25, no. 12, pp. 2759, January 2020. doi: 10.3390/molecules25122759. Abstract
    Stevia is a plant containing many active compounds, but usually propagated by stem cuttings because of low seed-yield-germination ability. The aim of this study was to investigate the impact of plant-growth regulators on stevia callus induction and growth from somatic tissue, as well as to determine the effect α-naphthalene acetic acid (NAA) and proline (PRO) on the amount of stevioside, rebaudioside A, phenols, flavonoids, and antioxidant activity. Stem and leaf segments were inoculated on a Murashige and Skoog (MS) medium supplemented with different concentrations of NAA and 6-benzylaminopurine (BAP) for callus genesis. The amount of steviol glycosides (SGs) was evaluated using high-performance liquid chromatography (HPLC), and the amounts of total phenols, flavonoids, and antioxidant activity by spectrophotometric methods. The highest callus-induction frequency and callus-mass increase were obtained from the leaf explants in MS medium supplemented with 2.0 μM NAA. The highest amount of SGs, phenols, and flavonoids, and stronger antioxidant activity were determined in the cellular compounds of callus from leaf explant. PRO reduced the amount of SGs and flavonoids. The significantly highest amount of total phenolic compounds was obtained in the callus from leaf explants in the medium supplemented with 2.0 µM NAA and 2.0 µM PRO.
38. Dey, Avishek and Bandyopadhyay, Abhijit and Bhattacharjee, Aloke, An Efficient in Vitro Multiple Shooting Method of Stevia Rebaudiana Bertoni., BIONATURE, pp. 89--95, February 2010. url: https://www.globalpresshub.com/index.php/BN/article/view/499. Abstract
    The small miracle plant\ Stevia rebaudiana\ Bert. is commercially important due to presence of a natural sweetner, stevioside (diterpene glycoside), a potent alternative to sucrose. Poor seed germinability limits its reproduction to only vegetative propagation by stem cuttings. This makes micropopagation most reliable method. Axenically grown cotyledonary leaves produce profuse calli (10mg/lit NAA-0.5mg/lit Kinetin), which subsequently develop microshoots. Vigorous microshooting (max 72.65, microshoots/explant)\ was noticed at moderate concentrations of Kinetin and BA (Kinetin 3mg/lit- 5mg/lit, BA 0.5mg/lit-3mg/lit) with maximum shoot length in minimum shoot initiation time. Most of such microshoots rooted efficiently (20 roots /shoot; 4cm root length) within 5-6 days of culture at high IBA concentrations (5mg/lit- 10mg/lit). Such efficient microshoots are being tested for their acclimatization and field establishment potential through routine hardening procedures. The objective of the study is to develop an elite line (microshoots) with high regeneration, good field transfer potential with sustained stevioside production.
39. Hasan, Fakhrul Razin, Macronutrients Screening on the Growth and Development of Stevia Rebaudiana (Bertoni) in Vitro Shoot Culture and the Yielding of Stevioside and Rebaudioside A. / Fakhrul Razin Hasan, 2015. url: https://ir.uitm.edu.my/id/eprint/15923/. Abstract
    Stevia rebaudiana (Bertoni) is a herbaceous plant which has an increasing demand in agricultural industry worldwide. This is due to the presence of the sweet glycosides in the leaves that are hundreds times sweeter than sugar and have zero calories.Previously, studies were focused on the increasing its yield such as growth regulator manipulation, light, water and temperature controlling in greenhouse and genetic modification of the herb. However, no study had been done on the macronutrients manipulation in Stevia rebaudiana (Bertoni). Therefore, the novelty of this study is, it is the first study in discovering the effects of macronutrients manipulation in Stevia rebaudiana (Bertoni) in vitro plantlets. This study aimed at screening the growth and development of Stevia rebaudiana (Bertoni), and the stevioside and rebaudioside A yield in different concentration strength of macronutrients. It was done by using onefactor-at-a-time (OFAT) technique. Different parts of the in vivo plants were separated and extracted in different solvents and analysed by using HPLC. Meanwhile, the sterile shoot tip explants were cultured onto MS basal media. After 1 month, several of these sterile plantlets were extracted in different solvents and analysed by using HPLC. The remained sterile plantlets were continued regenerated and multiplied to increase their quantities. Media with manipulated macronutrients (N, K, Ca, Mg, P and S) were prepared in different concentrations strength (0, 0.5x, lx, 2x, 4x and 8x) for each macronutrient element. The sterile plantlets were then cultured onto these modified media. After 1 month, the whole plantlets were oven dried and ground into powder for extraction in different solvents and analysed by using HPLC. Findings showed that in vitro shoots contain significantly high concentration of stevioside (22.63±0.25mg/ml), while in vivo leaves contain significantly high concentration of rebaudioside A (2230.40±26.72 mg/ml) as compared to other parts of Stevia rebaudiana (Bertoni). Results from this study also showed that the aqueous solvent was the best solvent to extract stevioside while methanol was the best solvent to extract rebaudioside A.Moreover, 4x K concentration produced highest number of leaves (22.00±2.21), highest number of nodes (9.40±0.85), highest fresh biomass (0.07±0.01g) and highest dry biomass (0.006±0.001g), while 8x S produced the highest shoot length (3.83±0.39cm). There is no direct relationship between macronutrients concentration increment towards physical characteristics and biomasses of Stevia rebaudiana (Bertoni) shoot culture. The proposed macronutrient concentrations in optimizing the growth and development of Stevia rebaudiana (Bertoni) shoot culture are lx N, 4x K, 8x Ca, 4x Mg, 8x P and lx S. Furthermore,media without Mg (Ox concentration strength) yielded the highest stevioside concentration (4.57±0.02mg/ml), while media without Ca (Ox concentration strength) yielded the highest rebaudioside A concentration (1709.10±6.44mg/ml). There is no direct relationship between the macronutrients concentration increment towards the stevioside and rebaudioside A yield. The proposed macronutrients concentration strength in yielding the highest stevioside concentration are 8x N, 0 K, 0.5x Ca, 0 Mg,8x P and 2x S while the proposed macronutrient concentration strength in yielding the highest rebaudioside A concentration are 4x N, 2x K, 0 Ca, 2x Mg, 0 P and 0.5x S. Findings from this study also showed that there is no direct relationship between the physical characteristics and biomass towards the stevioside and rebaudioside A yield.
40. Islam, S. A. M. Nurul and Tareq, Saiful Alam M., In Vitro Cloning and Stem Cutting of Stevia (Stevia Rebaudiana Bertoni.) for Mass Propagation in Chittagong, Bangladesh, The International Journal of Biotechnology, vol. 4, no. 3, pp. 14--19, March 2015. doi: 10.18488/journal.57/2015.4.3/57.4.14.19. Abstract
    Stevia (Stevia rebaudiana Bertoni.) is non-caloric sweetening plant. It was cloned using shoot tip in vitro MS medium supplemented with 6-Benzyl Amino Purine (BAP) and Kinetin (Kn). Excised shoots were rooted in half strength Murashige and Skoog (MS) medium supplemented with Indole-3 Butyric Acid (IBA). The rooted plantlets were transferred to soil and coconut husk filled bags and beds. Stem cutting method in sand medium with water misting propagation bed without plant growth regulator was effective for mass propagation. The plantlets derived from in vitro and stem-cutting grew luxuriantly in cultivating field during long day months (March to September) and produced gregarious flowering during short day months(October to February). Similar type of flowering behavior was observed between these two types of propagules of Stevia.
41. Khan, Mohd Kamran and Misra*, Pragati and Sharma, Taru and Shukla, P. K. and Ramteke, P. W., Effect of Adenine Sulphate on in Vitro Mass Propagation of Stevia Rebaudiana Bertoni, Journal of Medicinal Plants Research, vol. 8, no. 13, pp. 543--549, April 2014. doi: 10.5897/JMPR2013.5217. Abstract
    Stevia rebaudiana, a medicinal plant normally used as a natural herbal sweetener, has documented properties of antimicrobial, antihypertensive and anti-hyperglycemic and hence a boon to diabetic people. An efficient protocol has been developed for the in vitro plant regeneration established from nodal explants of stevia. Best shoot proliferation was observed when nodal explants were inoculated on Murashige and Skoog (MS) medium supplemented with Kinetin (9.3 \µM) and adenine sulphate (Ads) 40 mg/L. Proliferated shoots were transferred to rooting media having different concentration of \α-n-Naphthalene acetic (NAA) acid and Indole-3-butyric acid (IBA). Best rooting was observed with NAA 5.3 \µM. The plantlets were successfully subjected to hardening media containing soil, soilrite and vermiculite (2:1:1 w/w) and then rooted plant transferred to pots and acclimatized, which showed 65\% survival in the field with normal growth. Key words: Stevia rebaudiana, adenine sulphate, in vitro.
42. Kumar, Amit and Goswami, Aakansha and Sagar, Anubha and Kumar, Permod and Singh, Raj, Effect of Plant Growth Regulator on {\emph{In-Vitro}} Callus Induction and Shoot Proliferation of a Natural Sweetening Crop, Stevia Rebaudiana (Bertoni), Progressive Agriculture, vol. 19, no. 1, pp. 118, 2019. doi: 10.5958/0976-4615.2019.00015.2.
43. Modi, Arpan R. and Patil, Ghanshyam and Kumar, Nitish and Singh, Amritpal S. and Subhash, N., A Simple and Efficient In Vitro Mass Multiplication Procedure for Stevia Rebaudiana Bertoni and Analysis of Genetic Fidelity of In Vitro Raised Plants Through RAPD, Sugar Tech, vol. 14, no. 4, pp. 391--397, December 2012. doi: 10.1007/s12355-012-0169-6. Abstract
    An investigation was carried out to develop an efficient micropropagation protocol for Stevia rebaudiana Bertoni. Experiments were conducted to optimize suitable media for in vitro shoot multiplication and root induction and to study the effect of culture vessel on shoot multiplication. Out of the different media compared for in vitro shoot multiplication, hormone-free liquid medium was found the most suitable. The results also revealed that strength of Murashige and Skoog (MS) salt, culture medium consistency (solid or liquid) and type of culture vessel significantly influenced the in vitro shoot multiplication rate. The shoots when placed on half strength hormone free half MS medium and 100~ppm charcoal showed cent percent root induction with maximum number of roots per shoot (21.2) as well as maximum root length (4.22~cm). Hardening of rooted plants on biopeat showed more than 80~\% of survival rate. Further, clonal fidelity of the in vitro raised plants was carried out using RAPD markers and results indicated that all the tissue cultured derived plants are true-to-type and there are no somaclonal variations among these plants.
44. Nower, Ahmed Abbas, In Vitro Propagation and Synthetic Seeds Production: An Efficient Methods for Stevia Rebaudiana Bertoni, Sugar Tech, vol. 16, no. 1, pp. 100--108, March 2014. doi: 10.1007/s12355-013-0228-7. Abstract
    Germplasm can be effectively stored in the form of synthetic seeds. Shoot tips obtained from in vitro shoot cultures of Stevia rebaudiana Bertoni were encapsulated in 4~\% calcium alginate. The present work discussed the role of components of culture medium on morphogenic response of Stevia rebaudiana Bertoni encapsulated buds to various MS strengths and sugar alcohol (Mannitol or sorbitol) in different concentrations for long term storage. Germination ability of the synthetic seeds was investigated. Shoots were regenerated from nodal explants of Stevia through axillary shoot proliferation. The induction of multiple shoots from nodal segments was the highest in MS medium supplemented with 1.0~mg~l−1 BA. Maximum shoot formation was obtained with fructose at 20 and 40~g~l−1 fructose, while with fructose at 20~g~l−1 gave the highest leaves number/explants). The longest shoot length obtained with sucrose and fructose than other sugar. Different media type (NN and WPM) were suitable for best shoot number of Stevia, leaf number and shoot length than other media. Growth of shoot was increased and observed in capsules stored for 5~weeks on MS than other MS strengths. The growth of capsules dependent on mineral concentration and storage time. The most suitable conversions of capsules was using 0.05~M mannitol after 6~weeks from storage of synthetic seeds of Stevia. For rooting, when Stevia shoots cultured on MS medium supplemented with IAA, at 0.2~mg~l−1 resulted in the maximum number of roots/explant while, IBA at 1.0 and 2.0~mg~l−1 resulted in longest root/plant and gave the same length of root.
45. Rafiq, Muhammad and Dahot, Muhammad Umar and Muhamamd, Sher and Naqvi, Habib Ahmed and Qarshi, Iqbal Ahmed, In Vitro Clonal Propagation and Biochemical Analysis of Field Established Stevia Rebaudiana Bertoni, Pakistan Journal of Botany, vol. 39, no. 7, pp. 2474, 2007. Abstract
    An experiment was conducted to optimize growth medium and growth conditions for In vitro propagation of Stevia rebaudiana Bertoni through nodular stem sections. Varying concentrations of different growth regulators BAP, Kn, and IAA were applied through growth medium to assess their effects on shoots development while NAA and IBA were applied to assess their role in root formation. Although all plant growth regulators promoted shoot formation, maximum shoot formation was observed by supplementing 2.0 mgL-1 BAP. In contrast 0.5 mgL-1 NAA caused the maximum root formation in nodular stem sections of S. rebaudiana. Furthermore, survival rate of regenerated plants were 92 and 83\% during hardening and shifting to green house, respectively. Various biochemical attributes (carbohydrates, proteins) in the leaves were also measured and compared with leaf extract of Egyptian cultivar to assess its quality.
46. Razak, Ummi Nur Ain Abdul and Ong, Chong Boon and Yu, Tiew Sing and Lau, Li Kiaw, In Vitro Micropropagation of Stevia Rebaudiana Bertoni in Malaysia, Brazilian Archives of Biology and Technology, vol. 57, pp. 23--28, February 2014. doi: 10.1590/S1516-89132014000100004. Abstract
    Stevia rebaudiana Bertoni is a medicinal plants and commercially use as non-caloric sweetener for diabetic patient. In the present study, a protocol was developed for in vitro micropropagation using 6-benzylamino purine (BAP) and Kinetin (Kn) for the formation of multiple shoot proliferation and Indole-3-acetic acid (IAA), Indole-3-butyric acid (IBA) and 1-Naphthaleneacetic acid (NAA) for the induction of roots. Maximum shoot formation (7.82 ± 0.7 shoots per explants) was observed on a Murashige and Skoog (MS) medium supplemented with 0.5 mg L-1 BAP and 0.25 mg L-1 Kn. The maximum number of roots (30.12 ± 2.1 roots per explants) was obtained on a MS medium containing 1.0 mg L-1 IBA. The well rooted plantlets were successfully weaned and acclimatized in plant soil with survival rate of 83.3 \%.
47. Sairkar, P. and Ch, M. K. and {ravanshi} and Shukla, N. P. and Mehrotra, N. N., Mass Production of an Economically Important Medicinal Plant Stevia Rebaudiana Using in Vitro Propagation Techniques, Journal of Medicinal Plants Research, vol. 3, no. 4, pp. 266--270, April 2009. doi: 10.5897/JMPR.9000862. Abstract
    Experiments were conducted for standardization ofin vitroculture technique ofstevia rebaudiana, an important non-caloric sweetening herb to explore its potential for micro-propagation and callus culture. Nodal segments of the selected herb as explants were cultured for micro-propagation on MS medium containing 0.1 mg/l N6-benzyl amino purine for shoot initiation. Maximum plantlets (83.2 \± 0.445033) were found in MS medium treated with 3.5 mg/l N6-benzyl amino purine at multiplication stage. Young leaves were placed on MS medium containing 2 mg/l 2-4-Dichlorophenoxyacetic acid+1 mg/1 Kinetin was given best result of callusing. Higher regeneration of plantlets (3.8 plantlets/calli) was obtained by placing callus on MS medium with 5 mg/l BA + 1 mg/l NA. Highest rooting average (11.1 \± 0.264052) was recorded on1/2MS medium with 100 mg/l activated charcoal. The rooted plantlets were hardened in 1:1:1 ratio of sand: soil: vermicompost and successfully established in soil. Key words:Stevia rebaudiana,in vitropropagation, regeneration of callus, non-caloric sweetener, medicinal plant, N6-benzyl amino purine,2, 4-Dichlorophenoxyacetic acid.
48. Singh, Manvender and Saharan, Vinod and Dayma, Jyotsna and Rajpurohit, Deepak and Sen, Yadunandan and Sharma, Ajay, In Vitro Propagation of Stevia Rebaudiana (Bertoni): An Overview, International Journal of Current Microbiology and Applied Sciences, vol. 6, no. 7, pp. 1010--1022, July 2017. doi: 10.20546/ijcmas.2017.607.122.
49. Uddin, M. S. and Chowdhury, M. S. H. and Khan, Mmmh and Uddin, M. B. and Ahmed, R. and Baten, MdA, In Vitro Propagation of Stevia Rebaudiana Bert in Bangladesh, African Journal of Biotechnology, vol. 5, no. 13, 2006. doi: 10.4314/ajb.v5i13.43088. Abstract
    An experiment was conducted on in vitro culture of Stevia rebaudiana Bert, an important non-caloric sweetening herb to explore its potential for micro-propagation. Leaf, nodal and inter-nodal segments of the selected herb as explant were cultured on MS medium containing 2,4-D at 2, 3, 4 and 5 mg/L for callus induction. Inter-nodal segments initiated callus earlier than node and leaf. The highest amount of callus was found in MS medium with 3.0 mg/L 2,4-D and MS medium with 5.0 mg/L 2,4-D gave the poorest callus
50. Yang, Yau Wen and Chang, Wei Chin, In Vitro Plant Regeneration from Leaf Explants of Stevia Rebaudiana BERTONI, Zeitschrift für Pflanzenphysiologie, vol. 93, no. 4, pp. 337--343, July 1979. doi: 10.1016/S0044-328X(79)80267-6. Abstract
    Rapid plant regeneration of Stevia rabaudiana BERTONI (Composite) was achieved by culturing leaflets of 12 to 16-day-old seedlings on a modified Murashige and Skoog formulation (MS). Multiple shoots were induced on MS media supplemented with 2–10 mg/1 benzyladenine. Then roots were induced by subculturing the regenerated shoots on the MS medium without hormonal factors or on the moistened vermiculite. Successful transferring of plantlets to soil was accomplished and complete flowering plant formation was feasible in large scale.
51. Yücesan, Buhara and Mohammed, Aliyu and Büyükgöçmen, Refik and Altuğ, Cevher and Kavas, Özge and Gürel, Songül and Gürel, Ekrem, In Vitro and Ex Vitro Propagation of Stevia Rebaudiana Bertoni with High Rebaudioside-A Content—A Commercial Scale Application, Scientia Horticulturae, vol. 203, pp. 20--28, May 2016. doi: 10.1016/j.scienta.2016.03.008. Abstract
    Stevia rebaudiana Bertoni is a self-incompatible and the pollination is an entomophilous short-day plant. Rebaudioside A, as an individual steviol glycoside, is of particular interest in global sweetener market due to its most desirable flavour profile as compared to stevioside having aftertaste bitterness. In the present investigation, regenerant formation was performed for 6 weeks, in which randomly selected nodes excised from in vitro germinated seedlings were cultured on solid Murashige and Skoog medium (MS) with or without growth regulators (6-benzylaminopurine- BAP or kinetin- KIN) at various concentrations (ranging from 0.1 to 2.0mg/L). Irrespective of the medium composition, the results showed that all treatments were effective for shoot induction, producing an average of 2 shoots per explant after three weeks of culture. Following subsequent sub-culturing on MS medium at 3-week intervals, all the shoots regenerated from the nodes were transferred to MS medium with or without indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) or naphthalene acetic acid (NAA) at two different concentrations (0.25 or 0.50mg/L) for root formation for 3 weeks. IAA was more effective for root formation, producing 7.6 roots per shoot with 100\% rooting frequency. All the regenerants (∼13.5cm in length) were potted and successfully acclimatized in a greenhouse for 2 weeks, and then transferred to the field for 14 weeks with a high survival rate ({$>$}99\%). Similarly, seedlings (8 weeks-old) derived from seed germination in pots were also transferred to the same field in a different plot. There was no significant difference in terms of morphological, yield performance and steviol glycoside compositions between regenerants and seedlings sampled from two developmental periods (late vegetative and flowering period). It was clearly shown that clonal propagation using nodal explants was effective for superior stock plant production with high Reb-A content (11.7\% w/w).
52. Zayova, Ely and Stancheva, Ira and Geneva, Maria and Petrova, Maria and Dimitrova, Lyudmila, Antioxidant Activity of in Vitro Propagated Stevia Rebaudiana Bertoni Plants of Different Origins, TURKISH JOURNAL OF BIOLOGY, vol. 37, no. 1, pp. 106--113, February 2013. url: https://journals.tubitak.gov.tr/biology/abstract.htm?id=13354.
53. Taak, Pooja and Koul, Bhupendra and Chopra, Manpriya and Sharma, Kritika, Comparative Assessment of Mulching and Herbicide Treatments for Weed Management in Stevia Rebaudiana (Bertoni) Cultivation, South African Journal of Botany, vol. 140, pp. 303--311, August 2021. doi: 10.1016/j.sajb.2020.05.016. Abstract
    Stevia rebaudiana Bertoni is a commercially important natural sweetener plant and a boon to the diabetics. Unfortunately, its cultivation faces several abiotic and biotic constraints. Among the biotic ones, the most important is its poor competition with the weeds which culminates in 2-25\% yield penalty and further raises the cultivation and production cost. Hence, weed management for successful Stevia cultivation is a major challenge faced by Stevia-farmers. Present study aimed at assessing the effects of mulching (organic and synthetic) and herbicides treatments for efficient weed control and improving the yield of Stevia. Maximum weed control was recorded with herbicides spray while significant improvement in plant growth characteristics like, plant height (98.2 cm average), branch number (5.1 plant−1), leaf number (415 plant−1) and dry weight were recorded in plots treated with rice straw (organic mulch: @ 15t. h−1). Maximum leaf biomass was recorded in plots treated with eucalyptus leaves (organic mulch: @ 15t. h−1) during the year 2017. It is concluded that herbicide spray controlled the weed growth while the crop yield and growth parameters were successfully enhanced by the use of mulche(s), in both the years (2017–18). Meticulous use of mulches or mulch plus limited herbicide(s) application for weed control, may ensure sustainable agriculture and shall ultimately decrease the dependability on synthetic herbicides.
54. Angelini, Luciana G. and Tavarini, Silvia, Crop Productivity, Steviol Glycoside Yield, Nutrient Concentration and Uptake of Stevia Rebaudiana Bert. under Mediterranean Field Conditions, Communications in Soil Science and Plant Analysis, vol. 45, no. 19, pp. 2577--2592, October 2014. doi: 10.1080/00103624.2014.919313. Abstract
    Stevia rebaudiana Bertoni (Asteraceae Family), characterized by a high content of steviol glycosides (SG) in its leaves, represents an interesting source of non-sucrose and no-calorie sweeteners. Stevia, which is native to Paraguay, is a relatively new crop for the Mediterranean region, where it is grown as an annual or poly-annual crop. In order to assess the crop’s environmental requirements, productive performance and nutrient uptakes, a two-year field experiment was carried out in north-eastern Italy, where the species had never previously been cultivated. The aim was to evaluate the effects of important pre-harvest factors, such as cultivation site, harvest time and their reciprocal interaction, on productivity, leaf SG yield and nutrient requirements. Results showed that the timing of the harvest and the pedo-climatic conditions of the cultivation sites had a significant effect on the main biometric traits, total and leaf dry yield, SG production, macronutrient concentration and uptake.
55. Baral, Mary Ruth O and Salas, Ma Cecilia I, Development of Component Technology for High Yield and Quality Stevia (Stevia Rebaudiana Bertoni), no. 1, 2014. Abstract
    Two experiments conducted at the experimental field station of the Nueva Vizcaya State University from August 2013 to December 2013 aimed to develop a technology in the production of Stevia propagules using different stem cuttings and planted in different substrates. Field performance in terms of growth, yield, percent survival and quality were also studied. The first experiment was laid in 2 x 4 factorial in Completely Randomized Design (CRD) with three replications and the second experiment was laid in a 4 x 3 factorial in Randomized Complete Block Design (RCBD).
56. Serfaty, Mordechai and Ibdah, Mwafaq and Fischer, Ravit and Chaimovitsh, David and Saranga, Yehoshua and Dudai, Nativ, Dynamics of Yield Components and Stevioside Production in Stevia Rebaudiana Grown under Different Planting Times, Plant Stands and Harvest Regime, Industrial Crops and Products, vol. 50, pp. 731--736, October 2013. doi: 10.1016/j.indcrop.2013.08.063. Abstract
    Stevia rebaudiana (Bertoni) Bertoni is well known because of its accumulation of the sweet-tasting ent-kaurene diterpeneoid glycoside, which tastes about 300 times as sweet as sucrose. Although stevioside is one of the most abundant and best analyzed, more than 30 additional steviol glycosides so far have been identified and described. Stevioside concentration in the leaves is known to vary widely, depending on the growing conditions and agricultural practices. The present study aimed to examine the feasibility of growing Stevia as an open-field crop in Israel. In order to determine the agricultural practices required for optimizing Stevia biomass production and stevioside yield, effects of planting and harvest times upon plant development, biomass yield components, and stevioside content were examined. The optimal planting season, manifested in intensive plant development and maximal plant biomass yield, was at the beginning of spring, i.e., mid-March to early April. A minimal stand of 10 plants/m2 was found more favorable than lower stands of 6, 8, or 10 plants/m2′‘. The optimal harvesting time, with the highest stevioside yield of about 30g/m2 was at the beginning of September, prior to flowering initiation. Moreover, harvesting at this time yielded increased leaf biomass, highly suitable for commercial stevioside extraction. Thus, Stevia rebaudiana offers substantial potential for introduction as a commercial agricultural crop for stevioside production in Israel.
57. Das, Kuntal and Dang, Raman and Shivananda, T. N., Effect of Biofertilizers on the Nutrient Availability in Soil in Relation to Growth, Yield and Yield Attributes of Stevia Rebaudiana, Archives of Agronomy and Soil Science, vol. 55, no. 4, pp. 359--366, August 2009. doi: 10.1080/03650340802658432. Abstract
    A field experiment was conducted at Rani Chandramma Agricultural University (Arabhavi, Belgaum), Karnataka, India, in basic soil to study the nutrient availability in soil, yield and yield attributes of the medicinal plant stevia (Stevia rebaudiana). The results showed that the availability of nutrients such as nitrogen (N), phosphorus (P) and potassium (K) in the soil increased up to the fifth month; and thereafter, decreased by the same amount with the progress of the plant growth up to the sixth month, irrespective of treatments. Results also showed that the fresh and dry biomass yields significantly increased up to the sixth month with different treatments, but the yield attributes like plant height and the number of branches were observed to be varied with various treatments, being highest in the combined application of biofertilizers over that of their corresponding sole applications.
58. {Takács-Hájos}, Mária and Rubóczki, Tímea and Szabó, Fruzsina M. and Kiss, Annamária, Effect of Environmentally Friendly Nutrition Supply on Stevia (Stevia Rebaudiana B.) Production, Notulae Botanicae Horti Agrobotanici Cluj-Napoca, vol. 47, no. 1, pp. 201--206, 2019. doi: 10.15835/nbha47111232. Abstract
    The experiment was carried out on raised bed (3 rows) with 33 cm row distance and 25 cm between the plants and 24 plant m-2 density. The plantation was prepared on 28 May, 2015 with about 10 cm high transplants. The soil surface was mulched with wooden chips (5 cm layer). The aim was to evaluate the environmentally friendly fertilizers (Dudarit - 150 g m-2, Sprintalga – 0.04\% concentration four times 200 mL per plant). During the vegetation period pruning was applied at 30 cm plant height at the 4th double leaf from the soil surface and two cuttings (13 Aug and 29 Sept). By evaluating the effect of treatment on the leaf surface and chlorophyll content, statistically significant results were not found. Higher SPAD (relative chlorophyll content) value was measured in the middle of the growing period compared to the end of the vegetation when the plants were older and the temperature started to decrease. The positive effect of Dudarit and Sprintalga was clear on the plant height and biomass production. The dried herb yield was higher (4 kg m-2) on treated plots comparing to control (3 kg m-2). Although increased photosynthetic intensity was not detected on treated plots, the plantation showed greater vitality and side shoot improvement to control plots. Under our circumstances, the environmentally friendly fertilization (Dudarit and Sprintalga) has increased the dried leaves yield with 20\% by similar stevioside and rebaudioside-A content.
59. Taleie, Negar and Hamidoghli, Yousef and Rabiei, Babak and Hamidoghli, Saeid, Effects of Plant Density and Transplanting Date on Herbage, Stevioside, Phenol and Flavonoid Yield of Stevia Rebaudiana Bertoni, 2012. Abstract
    Stevia rebaudiana Bertoni is a natural sweetener plant. The leaves of Stevia are the source of glycosides. Even more, stevia contains a high percentage of phenols, flavonoids and antioxidant activity. Planting density and transplanting date are the most important agronomical factors that may affect the quality and quantity of yield. This study was conducted in Guilan province, on the base of a split-plot field experiment in a randomized complete block design for two cultivation seasons (2009-2010 and 2010-2011). Tissue culture-derived stevia plantlets were transplanted on 15 March, 30 March and 15 April in rows 50-cm apart with an inter-row spacing of 20, 25, 35, and 50 cm. Transplanting date and spacing significantly (P {$<$} 0.05) affected plant height, herbage (leaf and stem) fresh and dry weight and also stevioside, phenol and flavonoid yield. Maximum plant height (80 cm), total fresh (2017.21 g/m2) and dry (588.69 g/m2) herbage weight, and the highest stevioside (34.51 g/m2), phenol (1.5 g/m2) and flavonoid (1.97 g/m2) yield were obtained in the 50×20 cm spacing when plants were transplanted on the 15 March.
60. Shivani, Kumari and Gautam, Ghosh, Influence of Different Levels of Nitrogen on Yield and Economics of Stevia (Stevia Rebaudiana Bertoni) under Different Planting Geometry, International Journal of Chemical Studies, vol. 7, no. 3, pp. 806--809, 2019. url: https://www.chemijournal.com/archives/?year=2019&vol=7&issue=3&ArticleId=5610. Abstract
    Stevia (Stevia rebaudiana Bertoni) is a crop of economic importance due to its utilization as the alternative source of sugar. The productivity of stevia depends on many agronomical factors such as planting density, nutrient levels, field preparation, spacing etc. A field experiment was conducted during Zaid season 2018 in a clayey soil under irrigated conditions to study the “Influence of different levels of nitrogen on yield and economics of stevia (Stevia rebaudiana Bertoni) under different planting geometry. The experiment was laid out in randomized block design which comprised of 2 factors viz., Nitrogen levels (50, 75 and 100 kg ha-1) and Plant spacing S1 (30 cm x 20 cm), S2 (40 cm x 20 cm), and S3 (50 cm x 20 cm). The combination of 100 kg ha-1 N at (30 cm x 20 cm) spacing was proved to be best treatment in terms of highest fresh biomass yield (24.35 t ha-1), fresh leaf yield (10.54 t ha-1) and dry leaf yield (2.63 t ha-1). However, maximum leaf to stem ratio on fresh weight basis (0.78) and harvest index (0.44) was obtained in treatment T4 i.e., 75 kg ha-1 N at (30 cm x 20 cm) spacing.
61. Benhmimou, Benhmimou and Ibriz, Mohammed and Al Faïz, Chaouki and Gaboun, Fatima and Douaik, Ahmed and Amchra, Fatima Sahra and Khiraoui, Abdelkarim and Lage, Mounira, Stevia, Density, Harvesting Time, Steviol Glycosides, Dry Leaf Yield, Morocco, International Journal of Plant Research, vol. 7, no. 4, pp. 83--89, 2017. doi: 10.5923/j.plant.20170704.01. Abstract
    Stevia (Stevia rebaudiana Bertoni) has achieved economic importance due to the different natural steviol glycosides (SG) which are obtained from its leaves which are many times sweeter than sugarcane and sugarbeet. The produvtivity of stevia depends on many agronomical factors such as planting density. A field experiment was conducted from 10th May to 23rd October 2014 in a sandy soil under irrigated conditions to study the effect of plant spacing D1 (70 cm x 30 cm), D2 (70 cm x 20 cm), and D3 (70 cm x 10 cm) on growth, yield, and quality of stevia. Spacing significantly affected plant height, stem diameter, fresh biomass yield, fresh and dry leaf yield, stevioside (STV), rebaudioside A (Reb A), and total SG yield in all the harvests. Higher plant height (79.67 cm) and stem diameter (6.73 mm) were obtained in the wider spacing D1 as compared to closer spacing D3 (65.00 cm and 6.09 mm, respectively) in first harvest (95 days after transplanting). While, highest fresh biomass, dry leaf and total SG yields (cumulative of two harvests) were obtained with D3 (37.23, 4.95, and 0.69 t ha-1, respectively). SG contents were not significantly affected by planting density. However, higher STV and total SG contents were obtained with closer plant spacing D3 (11.27 and 17.20\%, respectively) in the first harvest. At the second harvest (72 days after first harvest) significantly lower dry leaf and SG yields were obtained in all the 3 planting densities. The study revealed that under Larache, Moroccan conditions, the higher dry leaf yield and better quality of stevia were obtained in the narrow spacing when plants were harvested during summer season.
62. Kumar, Rakesh and Sharma, Saurabh and Sood, Swati, Yield Components, Light Interception and Marker Compound Accumulation of Stevia (Stevia Rebaudiana Bertoni) Affected by Planting Material and Plant Density under Western Himalayan Conditions, Archives of Agronomy and Soil Science, vol. 60, no. 12, pp. 1731--1745, December 2014. doi: 10.1080/03650340.2014.909029. Abstract
    A field experiment was conducted to study the effect of planting material and plant density on stevia (Stevia rebaudiana Bertoni) under western Himalayan conditions during 2011 and 2012. The experiment conducted in a split plot design consisted of two types of planting material (rooted slips and fresh seedlings) in the main plot and five inter- and intra-row spacing in subplots with three replications. Yield attributes and dry leaf biomass yield of stevia were not affected by the type of planting material; however, plant density significantly influenced the yield attributes and leaf and stem dry biomass. Although the wider spacing (60 × 45 cm) gave more leaves, higher leaf area index, higher leaf dry mass per plant as compared to closer spacing, it resulted in lower values of these attributes per unit area. Plants spaced in 30 × 30 cm accumulated 41.2\% and 42.8\% more total biomass than 60 × 45 cm. Steviol glycoside content did not change due to different planting materials and plant densities; however, closer plant spacing (30 × 30 cm) recorded 114.8\% and 70.0\% higher steviol glycoside accumulation compared to wider row spacing (60 × 45 cm) in 2011 and 2012, respectively.
63. Mahajan, Mitali and {Anuradha} and Pal, Probir Kumar, Attaining Higher Biomass and Steviol Glycosides Yields of Stevia Rebaudiana through Adjustment of Plant Population and Nitrogen Rate, Industrial Crops and Products, vol. 165, pp. 113426, July 2021. doi: 10.1016/j.indcrop.2021.113426. Abstract
    Stevia rebaudiana is being cultivated in many parts of the world for its industrial uses as a low-caloric natural sweetener. However, the effects of plant population and nitrogen (N) levels and their interactions on biomass yield and steviol glycosides accumulation are not properly known in the mild-temperate conditions. Therefore, an experiment was laid out with ten treatment combinations having two plant densities (50,000 and 100,000 plants ha−1) and five N levels (0 to 160 kg ha−1). The overall dry leaf yield of stevia ranged from 1.74 to 3.35 Mg ha−1, while total steviol glycosides (SGs) concentration of the stevia leaf varied from 7.6 to 9.3\%. The dense population (100,000 plants ha−1) registered about 64.9 and 71.8\% higher dry leaf yields compared with thin population (50,000 plants ha−1) during 2014 and 2015, respectively. Irrespective of plant density, N at 120 kg ha-1 recorded significantly (P\,≤\,0.05) higher dry leaf yields (3.35 and 2.83 Mg ha−1) compared with control during both the experimental years. However, substantially higher apparent N-recovery and agronomic N-efficiency were registered with lower doses (40−80 kg ha−1) of N. The total SGs yield (g plant−1) was not reduced with dense plantation. Similarly, the significantly higher total SGs yield was recorded with the application of N at 120 kg ha−1. The response curve suggests that the dense plantation and N up to 143 kg ha−1 can be practiced to increase dry leaf yield of stevia without sacrificing the production of total SGs under mild temperate conditions.
64. Besheit and Nassar, A. M. and Allam, A. I. and Allam, S. M., Density Studies on Stevia Rebaudiana (Bertoni) in Egypt, Journal of Plant Production, vol. 27, no. 1, pp. 33--45, January 2002. doi: 10.21608/jpp.2002.247814. Abstract
    The fresh leaf yield and quality i.e. total soluble carbohydr- ates and stevioside (the main sweetening agent) of stevia under six plant densities of 24000 to 48000 plants/fed. resulted from the treatment combinations of three inter-row spacing (58.3, 70.0 and 87.5 cm) and two intra-row spacing (15 and 20 cm) using two seed types (seedlings resulted from tissue culture and root rizomes) of the variety Spanti from Spain imported were evaluated in Giza Experimental Station, Agricultural Research Center during the period of September 1998 to July 2000, where a ten successive cuts were carried out. Results revealed that: For seedlings, plant population density of 40000 plants/fed (70x15 cm) gave the highest leaf yield (4.304 tons/fed.). However, for rizomes planting, plant population of 36000, 40000 and 48000 plants/fed.( 58.3 x 20cm, 70 x 15cm and 58.3 x 20cm), respectively, yielded the highest leaf yield (7.158, 7.226 and 7.793 tons/fed.). For both seedling types, increasing or decreasing the population density beyond that induced significant reduction in fresh leaf yield. Total soluble carbohydrate and stevioside content in the leaves were not significantly affected by either inter or intra row spacing or their interaction with cutting times. Fresh Leaf yield was increased gradually and significantly in successive cuts for both seed types and this increased was more pronounced in summer cuts and in the latest cuts. On the other hand, cutting time insignificantly affected leaf content of total soluble carbohydrate and stevioside.
65. {Barbet-Massin}, Claire and Giuliano, Simon and Alletto, Lionel and Daydé, Jean and Berger, Monique, Towards a Semi-Perennial Culture of Stevia Rebaudiana (Bertoni) Bertoni under Temperate Climate: Effects of Genotype, Environment and Plant Age on Steviol Glycoside Content and Composition, Genetic Resources and Crop Evolution, vol. 63, no. 4, pp. 685--694, April 2016. doi: 10.1007/s10722-015-0276-9. Abstract
    Stevia rebaudiana (Bertoni) Bertoni is a perennial shrub native to Paraguay whose leaves accumulate sweetening compounds of high value: steviol glycosides (SVglys). These diterpenoids differ in the number (1–4) and the nature of sugar units bound to a steviol skeleton: mainly glucose but also rhamnose and xylose. The two main SVglys are stevioside (ST; 3 glucose units) and rebaudioside A (RA, 4 glucose units). Along with an evaluation of genotypic variability for SVglys content and composition, this study investigates the winter survival and the effect of perennial cultivation on S. rebaudiana genotypes through a 2-year experiment conducted on two locations. The first year, a population of 96 genotypes was examined in a nursery field (site A) and a subset of five genotypes was grown in a field trial (site B). The winter surviving genotypes (16 on site A and 5 on site B) were studied the following year, alongside new plantings of the same lines (8 on site A and 5 on site B). The genotypes showed a high variability in SVgly content (from 45.7 to 186.2~mg~g−1 DM) and composition along four distinct clusters. There was no correlation between total SVglys content and composition. Genotypes without RA had no other SVglys with more than three conjugated sugars. SVgly content varied among environments and generally increased between 1- and 2-year-old plants, while SVgly composition remained stable. This study showed that breeding for winter survival in temperate conditions would allow an increase in SVgly productivity in a semi-perennial stevia production.
66. Ramesh, K. and Singh, Virendra and Megeji, Nima W., Cultivation of Stevia [Stevia Rebaudiana (Bert.) Bertoni]: A Comprehensive Review, vol. 89, pp. 137--177, January 2006. doi: 10.1016/S0065-2113(05)89003-0. Abstract
    Stevia rebaudiana (Bert.) Bertoni is one of the 154 members of the genus Stevia. It is a sweet herb of Paraguay. The leaves of the shrub contain specific glycosides, which produce a sweet taste but have no caloric value. For centuries, this herbal sweetener has been used by native Guarani Indians to counteract the bitter taste of various plant‐based medicines and beverages. Many countries have shown interest in its cultivation, and research activities have been initiated. Incorporation of this species in agricultural production systems, however, depends upon a thorough knowledge of the plant and its agronomic potential. The published literature on research and development of this crop is meager. The aim of this chapter is to describe the ecology, importance of the plant, and its production requirements, but major emphasis is given to the agronomic and management aspects of the plant to be grown as a crop. Further, this chapter represents an effort to compile the literature on S. rebaudiana and review the current status of understanding of the plant and its potential as an alternate source of cane sugar.
67. Anchal, Shubham and Bahuguna, Sonam and {Priti} and Pal, Probir Kumar and Kumar, Devshree and Murthy, P. V. S and Kumar, Amit, Non-Destructive Method of Biomass and Nitrogen (N) Level Estimation in Stevia Rebaudiana Using Various Multispectral Indices, Geocarto International, vol. 37, no. 22, pp. 6409--6421, November 2022. doi: 10.1080/10106049.2021.1939436. Abstract
    Unmanned Aerial Vehicle (UAV) based remote sensing is one of the modern techniques for crop management, which has been used in this study for biomass and Nitrogen (N) level estimations for Stevia rebaudiana, a medicinal crop used as an alternative to sugar as a natural sweetener. Different levels of nitrogen treatments were given to S. rebaudiana and the crops were harvested for biomass estimation. Mica sense Altum multispectral sensor on board was used for acquiring the image data of the crop. The linear regression model was used to examine the best vegetation index using K-fold cross validation approach. Excess Green Index (ExG) was identified as best vegetation index for biomass estimation (R2 = 0.7; RMSE = 23.77 g/m2; nRMSE = 29.14\%), whereas Enhanced Normalized Difference Vegetation Index (ENDVI) was found as best predictor for Nitrogen (N) level estimation (R2 = 0.9; RMSE = 1.75 g/m2; nRMSE = 14.59\%).
68. Singh, D. P. and {Rajiv} and Kumari, Meenakshi and Prakash, H. G. and Kumar, Prabhat, Augmenting Commercial Yield of Stevia (Stevia Rebaudiana) through Agronomic Interventions in Indian Sub-Tropics, Sugar Tech, vol. 24, no. 5, pp. 1583--1589, October 2022. doi: 10.1007/s12355-022-01110-w. Abstract
    Field experiments were conducted to ascertain the effect of agronomical interventions on vegetative-yield and quality traits of stevia. The experiments were laid out in randomized block design with seven treatments of inorganic fertilizers (NPK @ 80:50:40~kg/ha) alone and integrated with organic sources (25, 50 and 75\% N through FYM and vermi-compost) and relative efficacy of these treatments were evaluated on the yield of stevioside. The pooled data for two year showed that the combined application of 75\% NPK through inorganic and 25\% N through vermi-compost produced highest plant height (64.26~cm), number of branches/plant (14.12), number of leaves/plant (136.54), leaf area/plant (1698 cm2), fresh leaves weight (34.62~g/plant), dry leaves weight (10.18~g/plant) and dry leaves yield (13.92 q/ha). However, the maximum yield of commercial product, i.e. stevioside content (11.88\%) and stevioside yield (1.47 q/ha), was recorded in dry leaves of plant fertilized with 50\% NPK through inorganic combined with 50\% N through vermi-compost. These studies have conclusively established that supplementing NPK with vermicompost or FYM in the range of 25–50\% has significant stimulatory effect on stevioside yield (1.09–1.47 q/ha) compared to recommended application of NPK alone (0.68 q/ha). It is therefore surmised that in order to get higher economic yield of stevia under central plain zone of North India, recommended dosage of NPK application should invariably be supplemented with 50\% vermi-compost/FYM.
69. Hirich, El Hocine and Bouizgarne, Brahim and Zouahri, Abdelmjid and Azim, Khalid, Agronomic Practices and Performances of Stevia Rebaudiana Bertoni under Field Conditions: A Systematic Review, Environmental Sciences Proceedings, vol. 16, no. 1, pp. 44, 2022. doi: 10.3390/environsciproc2022016044. Abstract
    Stevia (Stevia Rebauiana Bertoni) is one of the most renowned medicinal plants for its low calorific value. Stevia’s active components are steviol glycosides (SGs), which include Rebaudioside A, B, C, D, E, F, M, Stevioside, Steviolbioside, Dulcoside A, and Dulcoside C. These steviol glycosides are 150–300 times sweeter than sugar. The sweetening molecules stevioside and rebaudioside A are the most common. In this work, we performed a systematic review combined with a bibliometric analysis of stevia farming techniques in the field. The study is based on published literature data for the years 2000–2021. A sum of 54 articles was found, indicating that scientific study on stevia’s agronomic techniques and productivity in the field is currently insufficient. Asia, Europe, and South America were the major research production sites in this domain, accounting for more than 90\% of the research output. The number of articles dealing with density and planting that were examined was quite restricted. The principal themes covered in the scientific literature were the effects of “fertilization” and “irrigation”, followed by plant growth-promoting rhizobacteria “PGPR” and fungi “PGPF”, “salinity”, and “harvest” on stevia yield and quality. The results of this research will allow us to highlight insufficient available research works and knowledge gaps and the agronomic treatments that had the greatest impact on productive response were fertilization, irrigation, and salinity.
70. Büyük, Gökhan and Bayram, Ceren A. and Kırpık, Muzaffer and İnan, Memet, Agronomic Performance and Nutrient Content of Stevia (Stevia Rebaudiana Bertoni) in Different Semi-Arid Locations, Communications in Soil Science and Plant Analysis, vol. 53, no. 7, pp. 848--861, April 2022. doi: 10.1080/00103624.2022.2028819. Abstract
    Stevia (Stevia rebaudiana Bertoni) is a medicinal plant whose leaves are used as a natural sweetener. This study was carried out to determine the agronomic performances, yield, and macro-micronutrients in the leaves of the plant under semi-arid conditions. For this purpose, field experiments were conducted in four different locations (Kahta, Menderes, Hasancık and ADYÜTAYAM) of Adıyaman province which is located in the Southeastern Anatolia Region of Turkey. 0.5 ha of land was prepared for each location. Plots were created as three replicates and the seedlings were transplanted in 70 cm × 33 cm row distances. Plants were harvested 2 times in one growing season. Fresh and dry herb yields in the first harvest were measured as 13,949.5 and 3900.3 kg ha−1, respectively, and at the second harvest as 6923.5 and 1920.6 kg ha−1, respectively, from Menderes location. Something similar happened with regards to the ratio of leaves per plant. The K and Mn contents of leaves were not found to be statistically different. With regards to the macro and micro-nutrients measured in stevia leaves, N (2.29–3.40\%) and P (0.20–0.31\%), Zn (21.4–44.7 mg kg−1), Cu (13.8–34.5 mg kg−1) and Fe (204.1–446.9 mg kg−1) values were found to be statistically significant. These nutrients were affected by location and harvesting time. TSG, Reb A and Stevioside contents in stevia leaves were measured as 10.93\%, 4.73\% and 4.95\%, respectively. The results are similar to the values specified for Criolla variety. Considering the data obtained from the study locations, it was observed that stevia can be grown easily in semi-arid conditions. It is also concluded that at least two harvests can be taken in semi-arid conditions.
71. Kumari, Shivani and Ghosh, Gautam and Mesharm, Mayur Kumar, Total Soluble Solids, Yield, Nutrient Uptake and Energetics of Stevia (Stevia Rebaudiana) as Influenced by Nitrogen Levels and Spacing under Eastern U.P. Conditions, Current Advances in Agricultural Sciences(An International Journal), vol. 12, no. 2, pp. 117--120, 2020. doi: 10.5958/2394-4471.2020.00024.6.
72. Hossain, M. F. and Islam, M. T. and Islam, M. A. and Akhtar, S., Cultivation and Uses of Stevia (Stevia Rebaudiana Bertoni): A Review, African Journal of Food, Agriculture, Nutrition and Development, vol. 17, no. 4, pp. 12745--12757, December 2017. doi: 10.4314/ajfand.v17i4. Abstract
    Stevia [Stevia rebaudiana Bertoni; Family Asteraceae] is a natural sweetener plant that is grown commercially in many parts of Brazil, Paraguay, Central America, Thailand, Korea, China and India. The leaves of stevia are the source of sweet glycosides. It is mainly used as a sweetener and flavor enhancer in the food and beverage industry. The chemical compound obtained from stevia is considered to be the best alternative source of sugar especially for diabetes patients. Climatic factors and agronomical practices affect the quality and quantity of yield. The concentration of stevioside in the leaves is higher when the stevia plants are grown under long days and when these plants are harvested just prior to flowering. Time of harvesting depends on land type, type of stevia and growing season. The first harvest can be done four months after planting and subsequent harvest once after every 3 months. Such medicinal plants are becoming fairly popular for the treatment of different diseases all over the world. It could be suitable for diabetic and obese persons. It also showed antibacterial, antiseptic, anti-inflammatory, anti-fertility, hypotensive, diuretic and cardiotonic properties. Stevia is a small perennial shrub that has been used for centuries as a bio-sweetener and for other medicinal purposes. In addition, alternative sweeteners offer another benefit in maintaining good dental health. S. rebaudiana sweeteners are used sparingly and there seems to be no threat to public health. Stevia has been introduced to the Kenyan market as one of the cash crops for agro-based industry. The changes in leaf yield and accumulation of stevioside in response to different environmental conditions and nutritional variations might provide some leads to develop strategies for increasing the productivity of the stevia. Quality of the stevia product depends on drying temperature; high temperatures negatively affect quality, diminishing medicinal and commercial value. Multiple global regulatory organizations have determined that consumption of high quality stevia products within recommended doses is safe for all.Keywords: Stevia, Cultivation, Medicinal uses, Diabetes, Natural sweetener, Flavor enhancer, Glycosides
73. Stramarkou, Marina and Oikonomopoulou, Vasiliki and Karagianni, Elvira and Stamatis, Christos and Nana, Konstantina and Krystalli, Evangellia and Komaitis, Stratos and Krokida, Magdalini, Optimization of Green Extraction Methods for the Recovery of Stevia Glycosides, Chemical Engineering Transactions, vol. 87, pp. 43--48, July 2021. doi: 10.3303/CET2187008. Abstract
    In recent years, the rising rate of obesity and health problems associated with metabolic syndrome indicators (diabetes, cardiovascular, blood pressure) are turning consumers to exploring healthy, low-sugar and low-fat diets, as well as to using low-calorie sweeteners. In the current food market, sweeteners of synthetic origin, such as aspartame, sucralose, cyclamates etc. are available, which although they provide a sweet, calorie-free taste, they have often been accused of toxicity. This fact promotes the growing need for consumption of natural sweeteners, such as sweeteners from the plant Stevia rebaudiana Bertoni, which are 200-300 times sweeter than sugar and contain zero calories. The main objective of this work was to optimize the recovery of glycosides by dried stevia leaves. Dried samples were treated using green extraction techniques, namely ultrasound and microwave assisted extraction, using water as solvent, and extracts were compared with the conventional method. Several parameters, such as stevia / water ratio, time, temperature and power (microwave, ultrasound) were tested in order to optimize the glycoside recovery. The final extracts were evaluated for their total yield, antioxidant capacity and total phenolic content. The quantity and type of glycosides was also evaluated using HPLC. Based on the results, differences were observed between the extracts in terms of yield, antioxidant capacity and glycoside content. The optimum conditions were then used for the extraction of glycosides from samples that were dried and fertilized with different methods, to examine the effect of cultivation conditions on the quality and quantity of glycosides. Oven drying resulted in samples containing higher quantity of RebA and stevioside, while fertilization resulted in lower stevioside content.Keywords: ultrasound and microwave assisted extraction, freeze drying, phenolics, antioxidant activity, RebA, stevi
74. Turgut, Kenan and Karhan, Mustafa and Hacioglu, Ahmet and Yildiz, Melis and Unal, Narin, Effects of Different Harvest Times and Leaf Positions on Steviol Glycosides Content in Stevia Rebaudiana Bertoni Under Mediterranean Climate Conditions, Fresenius Environmental Bulletin, vol. 30, no. 9, 2021. url: https://avesis.akdeniz.edu.tr/yayin/e43ee57c-9c66-46f4-a5ba-956de26d28e6/effects-of-different-harvest-times-and-leaf-positions-on-steviol-glycosides-content-in-stevia-rebaudiana-bertoni-under-mediterranean-climate-conditions. Abstract
    The leaves of the stevia ( Stevia rebaudiana Bertoni) plant, a perennial plant from the Asteraceae family, contain glycosides such as Stevioside, Rebaudioside A, B, C, D, E and Dulcoside A, which are sweeter than sucrose. However, among these glycosides, Stevioside (Stv) and Rebaudioside A (Reb A) give the plant the main sweetening properties. Especially, the higher the amount of Reb A in the leaves, the higher the sweetener quality of the products. This sweetener is known to be 200-300 times sweeter than sugar. Since the sweetener obtained from the stevia does not need insulin secretion during digestion, it can be used by diabetics. It is also preferred in diet products due to its zero-calorie feature. Adaptation studies carried out in Antalya conditions have shown that stevia can be cultivated perennially. It is important to know the change of Reb A amount and Reb A / Stv ratio, which are very important for the sweetener quality of the stevia leaves, according to the plant's development period (ontogenetic) and the position of the leaves in the plant. In order to determine the most suitable harvest time, trial samples were taken on 20 July, 5 August, 20 August, 5 September and 20 September 2020 and the amounts of Reb A and Stv were determined. Also, Reb A and Stv analyses were performed in the lower, middle and upper leaf samples on the same plant. It is found that the 4th harvest time (September 5th) is superior to other harvest times in terms of both high leaf yield and high SGs amount in Antalya conditions. At this harvest date, Reb A / Stv ratio, which is important for leaf quality, was found to be high as well. On the other hand, the change in Reb A / Stv ratios in lower, middle and upper leaves at different harvest times was found to be significant.
75. Witono, Judy Retti and Chandra, Andy, The Study on the Method for Maximizing Steviol Glycoside Extract from Stevia Leaves, IOP Conference Series: Materials Science and Engineering, vol. 742, no. 1, pp. 012048, January 2020. doi: 10.1088/1757-899X/742/1/012048. Abstract
    One of the 9 types of basic needs of Indonesian is sugar. The main resource as a sugar producer is sugar cane. However, currently with the increasing of population, the area for sugarcane plantation become limited. On the other side, Indonesia, with its wealth of natural resources, has the opportunity to use other raw materials as a source of sweetener. One of the potential sugar sources is Stevia rebaudiana. Its dry leaves contents of steviol glycosides around 5-10\%. In addition, this sugar has a therapeutic function as well, since its sweetness level is quite high (200 - 300 times of sugarcane), contains vitamins, minerals and anti-oxidants. The aim of this research is to study the appropriate method that can maximize the extraction of glycoside from stevia leaves. The variables observed during the experiment were temperature generated by microwave and size of leaves. Stevioside separation process was carried out by extraction with using a microwave. Analysis of the glycoside yield was conducted using turbidity meter and colorimeter.
76. Gomes, Erik N. and Moterle, Diego and Biasi, Luiz Antonio and Koehler, Henrique S. and Kanis, Luiz Alberto and Deschamps, Cícero, Plant Densities and Harvesting Times on Productive and Physiological Aspects of Stevia Rebaudiana Bertoni Grown in Southern Brazil, Anais da Academia Brasileira de Ciências, vol. 90, pp. 3249--3264, 2018-Oct-Dec. doi: 10.1590/0001-3765201820170510. Abstract
    Abstract Stevia (stevia rebaudiana Bertoni) is a species characterized by producing non-caloric substances with high sweetening potential. Among these substances, rebaudioside A and stevioside are produced in greater quantity. Plant density and harvesting time are factors that affects biomass and sweetening compounds yield in this species. The objective of this research was to evaluate the effect of plant densities and harvesting times on the productive and physiological characteristics of stevia in southern Brazil. The experimental design was in randomized blocks, in a split-plot scheme, with 9 treatments comparing the effect of three planting densities (166 667, 83 333 and 33 333 plants ha-1) in the plots and three harvesting periods (before, in the beginning and in full flowering) in the subplots. Harvesting at the beginning of flowering promoted higher dry leaf biomass yield and, when associated with the lowest planting density, promoted higher levels of rebaudioside A and stevioside. The lowest planting density resulted in greater leaves biomass accumulation, whereas the highest density promoted higher yields per area. Interaction between density of 166 667 plants ha-1 and the harvest at the onset of flowering promoted higher yields of rebaudioside A (43.22 kg ha-1) as well as higher rebaudioside A/stevioside ratio (0.60).
77. {Hyo-Jun}, Lim and {Sang-Lyong}, Oh, Quality of Extracts from Domestic Stevia(stevia rebaudiana BERTONI) Leaves with Harvest Time, Korean Journal of Food Preservation, vol. 11, no. 4, pp. 491--495, 2004. url: https://koreascience.kr/article/JAKO200431234552293.page. Abstract
    천연 저 칼로리 감미료로써 stevia의 소비가 증가하고 있는 시점에서 재배 및 기능성 식품소재로 이용하기 위하여 수확시기별 특성을 조사한 결과는 다음과 같다. 가용성 고형분 함량과 추출수율은 성장 기간이 길어질수록 증가하였고, pH는 감소하는 경향을 보였다. 색도와 투과율은 큰 변화가 없었으나, 성장 시기가 길어질수록 L, a, b값은 유사한 감소 경향을 나타내었고, 갈색도는 증가하였다. 성장기간 중 stevioside와 rebaudioside A의 비율은 stevioside는 {$<$}TEX{$>\$$}68.97\textbackslash\%\${$<$}/TEX{$>$}에서 {$<$}TEX{$>\$$}61.09\textbackslash\%\${$<$}/TEX{$>$}까지 감소하고, rebaudioside A는 {$<$}TEX{$>\$$}20.83\textbackslash\%\${$<$}/TEX{$>$}에서 {$<$}TEX{$>\$$}27.52\textbackslash\%\${$<$}/TEX{$>$}까지 증가하였다. Stevia 잎의 감미성분함량은 성장함에 따라 일정한 수준으로 증가하여 최고치는 8월말이며 함량은 {$<$}TEX{$>\$$}12.80\textbackslash\%\${$<$}/TEX{$>$}였고, 9월말에는 함량이 {$<$}TEX{$>\$$}12.10\textbackslash\%\${$<$}/TEX{$>$}로 감소하는 경향을 보였다. 최고 감미도는 25 - 30배였으며 감미질은 5월말에 채취한 시료가 가장 우수하였다. Consumers were tend to purchase more natural sweeting materials then atificial sweeting materials because of safety and the consumed amount of natural sweeting material was increased sharply with consumers concern to health. The proper harvest time with changes of sweeting material contents was investigated in the purpose of cultivation and utilization on functional foodstuff, Soluble solid content and extraction yield were increased with growth priod, but pH was decreased. Color value, transmittance and browning color showed little. L, a, b values was changed a little. Stevioside ratio({$<$}TEX{$>\$$}68.97\textbackslash\%\${$<$}/TEX{$>$}) in sweetness components was decreased to {$<$}TEX{$>\$$}61.09\textbackslash\%\${$<$}/TEX{$>$}. Rebaudioside A ratio was increased from {$<$}TEX{$>\$$}20.83\textbackslash\%\textbackslash;to\textbackslash;27.52\textbackslash\%\${$<$}/TEX{$>$} stevioside contents was maximized to {$<$}TEX{$>\$$}12.80\textbackslash\%\${$<$}/TEX{$>$} of August. The highest sweetening potencies of stevia leaves was 2530times to sugar. The stevia leaves harvested at May showed the best deliciousness.
78. Li, Guo Qing and Liu, Xiang Yang and Shi, Yan, The Effect of Different Harvest Date on the Quality and Yield of Stevia Rebaudiana Bertoni, Advanced Materials Research, vol. 524--527, pp. 2109--2112, 2012. doi: 10.4028/www.scientific.net/AMR.524-527.2109. Abstract
    The effect of different harvest date on the quality and yield of stevia has been studied in the open field. The results showed that if the stevia was harvested at 65-85 days after transplanted, not only the yield was lower, but also the total content of glycosides of stevia and the content of Rebaudioside A (RA) and Stevoiside (STV) were lower. And the stevia harvested at 105 days after transplanted had similar results to that harvested at 65-85 days after transplanted. The results from the analysis to all the records of this experiment were that stevia could get the best quality and yield if they were harvested at 95 days after transplanted.
79. Martini, A. and Tavarini, S. and Macchia, M. and Benelli, G. and Canale, A. and Romano, D. and Angelini, L. G., Influence of Insect Pollinators and Harvesting Time on the Quality of Stevia Rebaudiana (Bert.) Bertoni Seeds, Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, vol. 151, no. 2, pp. 341--351, March 2017. doi: 10.1080/11263504.2016.1174173. Abstract
    Stevia rebaudiana (Bert.) Bertoni has sporophytic self-incompatibility and this may lead to poor seed yield and quality, which are obstacles to large-scale crop establishment. This research investigated the influence of insect pollinators and the harvesting time on the qualitative and quantitative characteristics of the ripe seeds. A pot trial under open field conditions was established to evaluate the abundance of insect pollinators and three harvesting times on the production of ripe seeds, germination percentage, mean germination time and thousand seed weight (TSW) in 36 F1 open-pollinated genotypes. Large variability in the number of corymbs of capitula, flowering time, reproductive period and seed yield was observed among the genotypes. Genotypes with promising phenological and reproductive properties were identified. The worst germination percentage and TSW were recorded in the latest harvest. Significant linear regressions were found among the investigated parameters (insect number, germination percentage, TSW, seeds yield per plant and cycle length), confirming complex interactions on the yield and quality of stevia seeds. Results indicate that earlier flowering genotypes produced higher seed quantity, due to favourable weather conditions during the reproductive phase. Moreover, cross-pollination and the insect abundance, as Apidae and Syrphidae, play a crucial role for enhancing the stevia seed yield and quality.
80. Pal, Probir Kumar and Mahajan, Mitali and Prasad, Ramdeen and Pathania, Vijaylata and Singh, Bikram and Ahuja, Paramvir Singh, Harvesting Regimes to Optimize Yield and Quality in Annual and Perennial Stevia Rebaudiana under Sub-Temperate Conditions, Industrial Crops and Products, vol. 65, pp. 556--564, March 2015. doi: 10.1016/j.indcrop.2014.09.060. Abstract
    Uses of the perennial crops have been proven to increase the sustainability in agriculture. However, information about the relative efficiency of annual versus perennial stevia (Stevia rebaudiana) under different harvest regimes is unknown in the sub-temperate region of western Himalaya in India. The harvesting time of stevia is generally controlled by growth behavior and accumulation pattern of the steviol glycosides (SGs). Our objectives were to standardize the harvesting regimes in both the cropping modes for higher yield and quality of stevia leaf. Thus a field experiment with six treatment combinations comprising two life cycles (annual and perennial) and three harvest regimes (single-cut, double-cut and triple-cut) was conducted. The total dry leaf yield was in the range of 1.40–4.11tha−1, and significantly (P≤0.05) highest dry leaf yield was recorded with the perennial stevia under three-cut management system (PH3) but remained statistically at par with PH2 (perennial with two-cut). However, PH2 produced maximum SGs (10.29g plant−1). The results of Principle component analysis reveal that PH2 and PH3 are equally effective and suitable management practices for dry leaf and SGs yield. Thus, our results suggest that the perennial stevia with two-cut management system is suitable for sustaining the stevia production in this condition.
81. Tavarini, Silvia and Angelini, Luciana G, Stevia Rebaudiana Bertoni as a Source of Bioactive Compounds: The Effect of Harvest Time, Experimental Site and Crop Age on Steviol Glycoside Content and Antioxidant Properties, Journal of the Science of Food and Agriculture, vol. 93, no. 9, pp. 2121--2129, 2013. doi: 10.1002/jsfa.6016. Abstract
    Background This study was aimed at identifying the effect of harvest time, experimental site and crop age on the no-calorie sweetener steviol glycosides (SG) and on the antioxidant properties of stevia leaf extracts. The experiment was conducted over two growing seasons at two sites in the northeastern plain of Italy. Results The results showed that all analysed factors played an important role in defining the SG profile and the antioxidant properties of stevia extracts. A high level of phenols (78.24 mg GAE g−1 DW by Folin–Ciocalteu method) and high antioxidant activity (812.6 µmol Fe2+ g−1 DW by FRAP assay) were observed. The inhibition of DPPH free radicals was evaluated and an IC50 mean value of 250 µg mL−1 was obtained. Significant relationships among the total antioxidant capacity and the analysed compounds were found. Conclusion The results showed the possibility of obtaining, in the tested environments, very high SG yields thanks to the long-day conditions during the spring/summer season. The harvest time played a key role in determining the stevia quality, influencing the rebaudioside A/stevioside ratio. The strong antioxidant properties make very interesting the possibility of using stevia extracts to improve functional food properties. © 2012 Society of Chemical Industry
82. Zaman, M. M. and Chowdhury, T. and Nahar, K. and Chowdhury, M. a. H., Effect of Cow Dung as Organic Manure on the Growth, Leaf Biomass Yield of Stevia Rebaudiana and Post Harvest Soil Fertility, Journal of the Bangladesh Agricultural University, vol. 15, no. 2, pp. 206--211, December 2017. url: https://www.banglajol.info/index.php/JBAU/article/view/35064. Abstract
    Organic manures as a source of plant nutrients for the cultivation of field crops has received worldwide attention due to rising costs, rapid nutrient loss and adverse environmental impacts from inorganic fertilizers. A pot experiment was conducted in the net house of the Department of Agricultural Chemistry, BangladeshAgriculturalUniversity, Mymensingh to observe the effects of cow dung on growth, yield of stevia along with post-harvest fertility status of soil. Four treatments of CD viz. 0, 5, 7.5 and 10 t ha–1 in two contrasting soils (acid and non-calcareous) were examined following Completely Randomized Design (CRD) with three replications. Growth and yield attributes increased significantly with the advancement of growth period (60 DAP) and increased rate of CD up to 10 t ha–1. An overall performance of non-calcareous soil was better than acid soil. In non-calcareous soil, the leaf biomass yield was increased by 275\% whereas in acid soil it was 268\% over control. The acidity of both soils significantly decreased with the increased rate of CD. All essential plant nutrients viz. total N, available P exchangeable K, Ca, Mg, available S, Zn, B and organic matter content of soil were significantly increased with the increased levels of CD up to its highest dose (CD @ 10 t ha–1) in both soils. Thus from the findings of the present research work it can be concluded that for getting optimum leaf biomass yield of stevia along with fertility of both soils CD should be applied @ 10 t ha–1J. Bangladesh Agril. Univ. 15(2): 206-211, December 2017
83. Zaman, M. M. and Chowdhury, M. a. H. and Islam, M. R. and Uddin, M. R., Effects of Vermicompost on Growth and Leaf Biomass Yield of Stevia and Post Harvest Fertility Status of Soil, Journal of the Bangladesh Agricultural University, vol. 13, no. 2, pp. 169--174, 2015. doi: 10.3329/jbau.v13i2.28772. Abstract
    In view of the growing awareness about eco-friendly organic farming, vermicompost (VC) could be a very good option for increasing crops yield. The organic carbon in VC releases nutrients slowly and steadily into the system and enables the plant to absorb these nutrients. To assess the effect of VC on soil fertility, growth and yield of stevia in acid and non-calcareous soils, an experiment was undertaken in the net house of the Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh, during February to May, 2012. Four levels of VC viz. 0, 5, 7.5 and 10 t ha-1 in two contrasting soils (Acid and Non-calcareous) were examined following CRD with three replications. Growth and yield attributes such as plant height, branch and leaf number, leaf area, fresh and dry weight of leaves were significantly influenced by different levels of VC. All the plant parameters increased with the advancement of growth period as well with increased rate of VC up to 7.5t ha-1 and then declined with further additions. The leaf biomass yield was 335\% and 338\% higher in acid soil and in non-calcareous soil, respectively over control. The overall performance of non-calcareous soil was superior to acid soil in terms of both plant and soil parameters studied. The acidity of both soils significantly decreased with the increased application of VC ranging from 4.9 to 5.7 in acid soil and 6.5 to 7.2 in non-calcareous soil. Total N, available P, exchangeable K, Ca, Mg, available S, Zn, B were also significantly increased with the increased levels of VC up to its highest level (VC @ 10t ha-1) in both soils. Thus the results suggest that VC @ 7.5t ha-1 should be applied for getting maximum leaf biomass yield of stevia and 10t ha-1 for increasing the fertility of both soils under the agro-climatic conditions of the studied area.J. Bangladesh Agril. Univ. 13(2): 169-174, December 2015
84. Bafhat, A. K. and Gupta, L. M. and Gupta, Meenakshi and Gupta, S. K. and Raina, N. S., Effect of Integrated Nutrient Management on Growth and Yield of Stevia ( Bertoni), Indian Journal of Ecology, vol. 49, no. 5, pp. 1965--1967, October 2022. doi: 10.55362/IJE/2022/3768. Abstract
    Field experiment was conducted at Sher-e-Kashmir University of Agricultural Sciences and Technology, Chatha, Jammu to study the integrated nutrient management technique suitable for increasing growth and yield in Stevia rebaudiana Bertoni. At the inception of the experiment, the soil was sandy-clay loam in texture, slightly alkaline in reaction having low status of available N with medium in available P and K. Application of vermicompost @ 1.5t/ha along with half of recommended dose of nitrogen(30kg N/ha) and Azotobacter significantly increased the growth and yield parameters over control and resulted in maximum plant height (66.17cm), number of branches per plant (24.87), number of leaves per plant (284.68), fresh leaf yield (23.35gm) and dry leaf yield per plant (5.98gm) compared to other fertilizer combinations, but it is at par with leaf yield in 30 kgN +vermicompost (VC) @1.5t/ha. Higher values of yield parameters are observed in vermicompost @ 1.5 t/ha in combination with 30 kg N and Azotobacter and 30kgN +vermicompost@1.5t/ha\vphantom\{\} with estimated dry leaf yield of 4.78q ha -1 and 4.32q ha-1, respectively. Maximum contents of NPK in soil after harvest of crop were in FYM @ 12t/ha and Azotobacter followed by VC @ 3t/ha alongwith Azotobacter. Integrated nutrient management comprising the use of VC or FYM in combination with inorganic fertilizers and biofertilizer was best combination of nutrient management compared to sole application of organic or inorganic to increase the leaf yield in stevia under Jammu subtropics. The combination of organic, inorganic and biofertilizers is not only superior over application of manures or fertilizers alone for achieving higher growth and yield but also in maintaining the fertility status of soil.
85. Vozhehova, Raisa and Lykhovyd, Pavlo and Biliaieva, Iryna and Shebanova, Vitaliya and Rudik, Oleksandr and Sinhaievskyi, Andrii, Modeling Stevia Yields Depending on Plant Density and Mineral Fertilizers Rates, Modern Phytomorphology, vol. 15, no. 4, pp. 82--85, 2021. doi: 10.5281/zenodo.5801191. Abstract
    Stevia is one of the most prospective sweeteners and medicinal plants in dietic treatment. The crop is cultivated almost worldwide, however the cultivation technology is still studied insufficiently. The generalization of current achievements of Ukrainian and foreign scientists in the field of stevia cultivation was used as the basis for the creation of mathematical models of crop productivity depending on plant density and NPK fertilizers rates. The mathematical models, developed using the means of polynomial and multiple linear regression analysis, provided reasonable accuracy of the crop yield prediction (MAPE-28.77\%-52.86\%). The lowest errors (MAPE3.09\%) were observed for the model of stevia productivity depending on plant density, which was created using an artificial neural network approach. It was determined that the best yields of stevia are obtained under the plant density of 80-120 thousand plant/ha and mineral nutrition with phosphorus and potassium fertilizers, while nitrogen ones are less important.
86. Ho, Zhi Wei, The Effect of Different Nitrogen and Potassium Nutrient Levels Used in Hydroponic System on the Growth and Steviol Glycosides Production in Stevia Rebaudiana Bertoni, 2022. url: https://eprints.tarc.edu.my/22528/. Abstract
    Stevia rebaudiana Bertoni is a branched bushy shrub belonging to the Asteraceae family. Stevia rebaudiana contains various sweet-tasting diterpene glycosides in the leaves and has long been used as natural sweeteners. Stevioside and rebaudioside A are the two most abundant steviol glycosides and both are sweeter than sucrose. In recent years, stevia has become popularly used in the food and beverage industry. However, low biomass yield of the S. rebaudiana leaves which is dependent on the agricultural practices will lead to low yield of steviol glycosides extracted. Therefore, a study on the effect of different nitrogen (N) and potassium (K) levels on the growth and production of steviol glycosides, stevioside and rebaudioside A, of S. rebaudiana was undertaken. In this study, there were a total of seven treatments, which were 200\% N, 150\% N, 50\% N, 200\% K, 150\% K, 50\% K and 100\% as control. There were 10 S. rebaudiana plants in each treatment, five plants per replicate, and two trials were done in Farm Box in a controlled environment with a hydroponic system, and also in a greenhouse, which was an uncontrolled environment at Tunku Abdul Rahman University College Johor branch campus. The growth parameters such as height, number of leaves, leaves area, and the chlorophyll content of the young leaves were measured for every 7 days from day 1 until day 35, the day of harvest. The soxhlet extraction was done after the drying of the S. rebaudiana leaves. The leaf extract was further analyzed by using HPLC for the qualitative analysis. From this study, the 150\% N and 150\% K had the best growth to the height: N (13.28 ± 3.72), K (17.29 ± 2.10), number of leaves: N (52.00 ± 17.73), K (97.50 ± 15.04), leaves area: N (5.66 ± 2.80), K (16.75 ± 5.99), chlorophyll content: N (31.35 ± 1.92), K (26.99 ± 1.77), biomass of leaves: N (2.59 ± 0.87), K (3.21 ± 1.08) of the S. rebaudiana that were planted in Farm Box with the controlled environment. Besides, the 200\% N and 200\% K had the best growth to the height: N (18.8 ± 7.53), K (8.86 ± 2.84), number of leaves: N (51.4 ± 7.73), K (32.00 ± 9.27), leaves area: N (4.36 ± 1.51), K (3.93 ± 1.15), chlorophyll content: N (16.48 ± 3.58), K (17.36 ± 1.71), biomass of leaves: N (0.52 ± 0.16), K (0.32 ± 0.09) of the S.rebaudiana that were planted with cocopeat in a greenhouse with the uncontrolled environment. With the qualitative analysis of HPLC, the stevioside and rebaudioside A were proved to have presence in the S. rebaudiana plant with the retention time of 10.83 min and 10.84 min.
87. Khiraoui, Abdelkarim and Bakha, Mohamed and Boulli, Abdelali and Hasib, Aziz and Al Faiz, Chaouki, The Productivity of Stevia Rebaudiana (Bertoni) on Dry Leaves and Steviol Glycosides of Four Varieties Grown in Six Regions of Morocco, Biocatalysis and Agricultural Biotechnology, vol. 37, pp. 102151, October 2021. doi: 10.1016/j.bcab.2021.102151. Abstract
    Stevia rebaudiana Bertoni, is a perennial herbaceous plant native to Paraguay. This plant produces diterpene glycosides that are powerful natural low calorie sweeteners, about 300 times sweeter than saccharose. Stevia has now become an important agricultural crop for the production of a high-potency natural sweetener. Cultural practices are still in development and the productivity potential of desirable steviol glycosides in more or less stable proportions and under different agriculture conditions are largely unknown. Currently, commercial growers and processors all over the world are seeking to maximize the productivity of rebaudioside A, a steviol glycoside. The present study aimed to characterize the effects of region and varieties on stevia dry leaf yield, steviol glycoside content, and steviol glycoside yield under Moroccan conditions. The content of steviol glycosides obtained from dry leaves of four varieties of Stevia rebaudiana, compared to the edaphoclimatic conditions in six different areas in Morocco, was determined using High-Performance Liquid Chromatography (HPLC). Dry leaf yield, leaf steviol glycoside content, and leaf steviol glycoside yield varied according to varieties and regions, with significant interaction of varieties by regions. Dry leaf yield varied from 1.57 to 7.86~t/ha. Stevioside yield ranged from 57.04 to 739.77 kg/ha and rebaudioside A yield varied between 60.8 and 614.04~kg/ha, with Reb A/STV ratios that reached up to 2.62. The total of steviol glycosides yield ranged from 163.21 to 1353.2~kg/ha with significant interactions between regions and varieties concerning sweet glycoside contents. Stevia offers great potential for introduction as a commercial crop producing a biological sweetener under Moroccan conditions.
88. {Lozano-Contreras}, Mónica Guadalupe and {Ramírez-Jaramillo}, Genovevo and {Ramírez-Silva}, Jorge H., Interaction Effects between Organic Fertilizers and Biofertilizers on the Growth of Stevia Rebaudiana Bertoni, Open Access Library Journal, vol. 8, no. 11, pp. 1--13, October 2021. doi: 10.4236/oalib.1108065. Abstract
    In the last decade Stevia rebaudiana, has become one of the most demanded crops in the market dedicated to health care and food. However, the main consuming countries, from Asia and Europe, are constantly demanding organic products. Therefore, the purpose of this study was to evaluate the effect of organic fertilizers in combination with biofertilizers in the growth of Stevia. A randomized block design with divided plots (large and small) and three replications were used. In the large plots, the cuttings of stevia were inoculated with 1) Rhizophagus intraradices fungus (Rhiz); 2) A mixture of bacterias Bacillusspp. (Bacl) and Azospirillum brasilense (Azo); 3) Trichoderma spp. fungus (Trch); 4) A treatment with no inoculant (c). These inoculation treatments were combined, in the smaller plots with three sources of organic fertilizers named: 1) Sheep manure (Shim); 2) Bocashi (Bcsh); 3) chicken manure (Chm); 4) A treatment with any organic fertilizer. The plot with no inoculants nor organic fertilizers was the Absolute Control (Ac). There was a positive relationship between organic fertilizers and biofertilizers in the growth of Stevia. The highest yield corresponded to the Rhiz + Bcsh with 450.00 kg·ha-1 followed by Rhiz + Shim, and Trch + Chmboth with 410.00 kg·ha-1. The treatment with the lowest yield was the Ac with 120.00 kg·ha-1.
89. Amien, Suseno and Maulana, Haris and Ruswandi, Dedi and Nurjanah, Sarifah, Genetic Gain and Relationship of Yield and Yield Attributes of Mutant and Cross-Bred Stevia (Stevia Rebaudiana) Genotypes, Biodiversitas Journal of Biological Diversity, vol. 22, no. 8, July 2021. doi: 10.13057/biodiv/d220805. Abstract
    Abstract. Amien S, Maulana H, Ruswandi D, Nurjanah S. 2021. Genetic gain and relationship of yield and yield attributes of mutant and cross-bred stevia (Stevia~rebaudiana) genotypes. Biodiversitas 22: 3119-3126. Plant breeding programs involved many traits and genetic parameters in the selection process. The information on genetic parameters on yield and other related traits provided an overview for breeders and farmers in selecting new superior genotypes. The purpose of this study was to estimate genetic parameters including heritability and genetic gains in yield and other traits, to determine the relationship between various traits, and to select superior stevia (Stevia rebaudiana Bertoni) genotypes for each trait. Field experiments were carried out in two planting environments, namely, the highlands and the medium plains employing a randomized completed block design and each genotype was three replicates. The results showed that the yield had high heritability and genetic gains~ ??in mutant populations, whereas cross-bred populations had moderate heritability and low genetic gains. Stem weight (SW) and number of leaves (NoL) traits were identified as having high heritability and genetic gains in both populations. The GT biplot measurement showed that the yield was identified to have a significant and positive correlation with SW (p\<0.05). H4 was correlated with Number of branches (NoB), Yield, SW, and chlorophyll content (Chl) traits in the cross-bred populations. H9 excelled on and was correlated with NoL and plant height (PH). M11 was identified to be highly correlated with NoL, PH, NoB, and Chl traits in the mutant populations, while M15 excelled on and was correlated with yield and SW. The results of this study revealed that there was a potential for improvement in the traits tested of stevia through cross-bred and mutant populations in different environmental conditions. The selected genotypes can be developed in a suitable environment and used for further stevia plant breeding programs.
90. Youssef, Mohamed Ahmed and Yousef, Ahmed Fathy and Ali, Muhammad Moaaz and Ahmed, Alshaymaa I. and Lamlom, Sobhi F. and Strobel, Wacław Roman and Kalaji, Hazem M., Exogenously Applied Nitrogenous Fertilizers and Effective Microorganisms Improve Plant Growth of Stevia (Stevia Rebaudiana Bertoni) and Soil Fertility, AMB Express, vol. 11, no. 1, pp. 133, September 2021. doi: 10.1186/s13568-021-01292-8. Abstract
    The effects of different fertilizers and biofertilizers on crop production to increase plant growth, improve quality and yield components (dry leaves yield, leaf protein, and stevioside) of crops has been extensively studied. However, the combination of both types of fertilizers have rarely been investigated. To explore the effect of different fertilizers and biofertilizers on stevia plant, a two-year field experiment was conducted to investigate the growth response of stevia plants under the influence of nitrogenous fertilizers (NFs) and effective microorganisms (EM). The experiment was laid out in a split-plot design, with EM as the main plot factor (−EM and +EM) and NFs as the subplot factor [control, chemical NFs (Ch-N) and organic NFs (Org-N)]. The results showed that, plants treated with EM and Org-N showed 2-, 2.2-, 2.4-, 2.5-, 3.3- and 3-fold increases in plant height, number of branches, total leaf area, plant fresh weight, plant dry weight and leaf dry yield, respectively, compared to untreated plants. Similarly, plants receiving EM along with Ch-N showed 1.86-, 1.7-, 2.2-, 2.12-, 3-, and 2.72-fold increases in the same traits. Total chlorophyll, protein, N, P, K and sativoside contents were increased by 88.8, 152, 138, 151.5, 43 and 137.5\% when EM and Org-N were applied to stevia plants. Application of EM together with Ch-N increased these properties by 0.5, 127.7, 115, 216, 42.6 and 83.8\%, respectively in the same traits. Overall, the combined application of NFs and EM improved growth, yield and nutrient accumulation in stevia plants.
91. Hoseini, Raziye Zare and Goltapeh, Ebrahim Mohammadi and {Modarres-Sanavy}, Seyed Ali Mohammad and Heidarzadeh, Ali, Effect of the Bio-Fertilizers on the Steviol Glycosides (SGs) Content and Biomass in Stevia Rebaudiana (Bert.) Bertoni at Vegetative and Flowering Stages, Scientia Horticulturae, vol. 275, pp. 109658, January 2021. doi: 10.1016/j.scienta.2020.109658. Abstract
    Stevia rebaudiana Bertoni is a unique medicinal herb mostly utilized for substitution of the sugar, producing zero-calorie sweeteners known as steviol glycosides (SGs), including stevioside (ST), rebaudioside A (RA), rebaudioside F (RF), rebaudioside C (RC) and dulcoside (DU). While bio-fertilizers have been demonstrated to enhance the production of secondary metabolites in many plant species, their effects on S. rebaudiana have not been thoroughly studied. This paper presents a study on the effects of bio-fertilizers and their interactions on modifying and improving the SGs content and biomass production in S. rebaudiana at two growth stages, vegetative and flowering. Vermicompost (V) and cow manure (M) (as soil amendments), and garden soil (S) were used separately, and also in combination to fill pots. In this research two factors included cultivation bed [S (control), SM (garden soil + 15 \% cow manure + 0\% vermicompost), SMV10 (garden soil + 15 \% cow manure + 10 \% vermicompost), and SMV20 (garden soil + 15 \% cow manure + 20 \% vermicompost) by \%weight in pots (w/w)], and fungi application (two species of fungi Funneliformis mosseae (Fm), Serendipita indica (Si) inoculation and without fungi inoculation) were investigated on the percent, yield of SGs and biomass at vegetative and flowering stages. The percentage and yield of total SGs, SGs elements [(ST, RA, RF, RC, DU, and RA/SGs ratio] and aerial dry biomass of S. rebaudiana were significantly affected by all treatments and their interactions (P\,{$<$}\,0.01). Generally, the highest SGs elements percentage was obtained in the control plant at the vegetative and flowering stages (S). Also, the highest SGs yield was observed in SMV20Fm in both vegetative and flowering stages. Funneliformis mosseae, in combination with SMV20, had shown significant effects on RA/SGs ratio, SGs yield, and plant aerial dry biomass in vegetative and flowering stages.
92. Coelho, Luísa and Osório, Júlio and Beltrão, José and Reis, Mário, Organic Compost Effects on Stevia Rebaudiana Weed Control and on Soil Properties in the Mediterranean Region, Revista de Ciências Agrárias, vol. 42, no. 1, pp. 109--121, February 2019. doi: 10.19084/RCA18281. Abstract
    Stevia rebaudiana Bertoni is a promising crop for semiarid climates, including Algarve region. The objectives of this work were: to compare the feasibility of the eco-friendly stevia weed control strategy with a compost of vegetable residues (grass clippings and pruning’s); to identify the emerged weed species, and to evaluate the effect of compost application on soil properties. Treatments consisted on the application of a 5 cm layer of compost on soil surface or incorporated, and no compost application as control. The trial was set up in six randomized field plots, with four replications. Each plot was divided into three subplots, with one treatment per subplot, in a total of 24 subplots per treatment. Compost application had a distinct effect on weed species. Some species were significantly reduced when compost was applied, namely as mulch. Compost increased soil water content, mainly in area of the trial with lower soil drainage, especially when compost was applied as mulch, as well as other physical and chemical soil properties. Results showed the positive effect of compost on weed control and soil properties during stevia cultivation.
93. Sun, Yuming and Hou, Menglan and Mur, Luis A. J. and Yang, Yongheng and Zhang, Ting and Xu, Xiaoyang and Huang, Suzhen and Tong, Haiying, Nitrogen Drives Plant Growth to the Detriment of Leaf Sugar and Steviol Glycosides Metabolisms in Stevia (Stevia Rebaudiana Bertoni), Plant Physiology and Biochemistry, vol. 141, pp. 240--249, August 2019. doi: 10.1016/j.plaphy.2019.06.008. Abstract
    Steviol glycosides (SGs) in Stevia (Stevia rebaudiana Bertoni) leaves are important due to their high sweetness and low calorific value. The yield of SGs is dependent on fertilization regimes, but the relationship between nitrogen (N) administration and SGs synthesis is still unclear. In this study, we investigate the effects of N rates on SGs production through hydroponic and plot experiments. The SGs yield was not significantly changed by N fertilization, but leaf SGs concentrations were significantly reduced due to the “dilution effect”. Additionally, N addition decreased leaf carbon (C)/N ratio and soluble sugar concentration, accompanied with the inhibited phosphoenolpyruvate carboxylase and L-phenylalanine ammonia\_lyase activities. A significant positive correlation between leaf SGs concentrations, C/N ratio and soluble sugar concentration was observed. Overall, we suggest that N-driven Stevia growth negatively affects SGs concentrations. The leaf C/N ratio and soluble sugar changes indicated the occurrence of metabolic reprogramming.
94. Ahmed, T.E.S., Potential Evaluation of Applicative Integration of Gamma Radiation Electric Current and Elicitor Agent on Quantitative and Qualitative Biomass Yield Improvement in Stevia Rebaudiana Bertoni, 2016. Abstract
    Stevia, stevia rebaudiana, nowadays is converted from wild perennial short-day plant to modern and vital medicinal annual crop for its leaves contents for bioactive metabolites that had a broad spectrum of therapeutic effects on human health management Therefore to meat the over increasing national and international demands for the endogenous systems of medicinal and pharmacological industries, economic benefits to provide remunerative returns to the farm community and international trade too stevia was introduced from its origin habitat, paraguay and cultivated commercially as an annual crop in many countries at that stevia seeds were exotic from spain, Since 15 February 1998 as a new sweetener crop that well adapted to Egyptian agriculture
95. Aladakatti, Y R and Palled, Y B and Chetti, M B and Halikatti, S I and Alagundagi, S C and Patil, P L and Patil, V C and Janawade, A D, Effect of Irrigation Schedule and Planting Geometry on Growth and Yield of Stevia (Stevia Rebaudiana Bertoni.), 2012. Abstract
    A field experiment was conducted in medium black, clayey soil under irrigated conditions to assess the response of stevia to irrigation schedules and planting geometry. Highest dry leaf yield of stevia (cumulative of five cuttings) was obtained with irrigation scheduled at 1.2 IW/CPE (10.54 t ha-1) which was on par with irrigation scheduled at 1.0 IW/CPE (10.32 t ha-1) and significantly lower dry leaf yield was with irrigation scheduled at 0.8 IW/CPE (9.36 t ha-1). Planting geometry of 30 cm x 20 cm recorded the highest cumulative total dry leaf yield (11.12 t ha-1) which was comparable with the dry leaf yield obtained with the planting geometry of 30 cm x 30 cm (10.89 t ha-1). Significantly lower dry leaf yield was recorded with planting geometry of 45 cm x 30 cm (8.73 t ha-1). Interaction effects of irrigation schedules and planting geometry on dry leaf yield of stevia were not significant. Consumptive use of water was highest with irrigation scheduled at 1.2 IW/CPE (2373.2 mm) closely followed by 1.0 IW/CPE (1903.8 mm). The study revealed that irrigation schedule at 1.0 IW/CPE i.e., irrigation at 60 mm cumulative pan evaporation (CPE) with planting geometry of 30 cm x 30 cm (1,11,111 plants ha-1) was found optimum for higher stevia dry leaf yield and higher water use efficiency. Based on the average daily evaporation the irrigation interval of 9-10 days during kharif, 5-6 days during summer and 7-8 days during rabi season can be recommended in similar soil and agro climatic conditions.
96. Aladakatti, Y R and Palled, Y B and Chetti, M B and Halikatti, S I and Alagundagi, S C and Patil, P L and Patil, V C and Janawade, A D, Effect of Nitrogen, Phosphorus and Potassium Levels on Growth and Yield of Stevia (Stevia Rebaudiana Bertoni.), 2012.
97. Ameer, Kashif and Bae, Seong-Woo and Jo, Yunhee and Chung, Namhyeok and Gao, Yaping and Kwon, Joong-Ho, Optimization and Modeling for Heat Reflux Extraction of Total Yield, Stevioside and Rebaudioside-A from Stevia Rebaudiana (Bertoni) Leaves, Separation Science and Technology, vol. 52, no. 7, pp. 1193--1205, May 2017. doi: 10.1080/01496395.2017.1285313. Abstract
    Stevia rebaudiana (Bertoni) leaves consist of stevioside and rebaudioside-A (Reb-A). This research sought to improve extraction of target steviol glycosides from stevia leaf powder using response surface methodology (RSM) and artificial neural networking (ANN) under these independent variables: ethanol concentration, X1 (0–100\%), extraction temperature, X2 (55–75°C), and extraction time, X3 (45–75 min). ANN outperformed as potential alternative to RSM in predicting optimum conditions. Maximum responses were obtained at 100\% X1, 55°C X2, and 60 min X3. Heat reflux extraction proved superior to maceration extraction in terms of higher extraction yields with reduced energy consumption and CO2 emission.
98. Anu, Jalpot and Rupinder, Tewari and Harsh, Nayyar, Effect of Organic Compost, Tricalcium Phosphate and PGPB in Enhancing Growth and Glycoside Constituents in Four High Yielding Varities of Stevia Rebaudiana - ProQuest, International Journal of Science, Engineering and Computer Technology, vol. 5, no. 1, pp. 1--6, March 2015. url: https://www.proquest.com/openview/b2d4de8fb1a74767e7f6e82777890163/1?pq-origsite=gscholar&cbl=2032130. Abstract
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99. Asrul Afandi Ab. Halim, Optimization of Rebaudioside a Yield from Stevia Rebaudiana Cultivated on Bris Soil and Its Biological Activities, 2015. url: http://umkeprints.umk.edu.my/5035/. Abstract
    Stevia rebaudiana is a sweet perennial herb which has been widely cultivated through the world for the sweet diterpene glycosides. S. rebaudiana has been applied as substitutes for sucrose, for treatment of diabetes mellitus, obesity, hypertension and caries prevention. Among the diterpene glycoside, rebaudioside A showed the lowest bitterness and the taste is close to sucrose. In this study two varieties MSR012 and MSR007 obtained from MARDI, Bachok, Kelantan were studied to maximize the yield of rebaudioside A from S. rebaudiana grown on BRIS soil. In order to find the best harvesting time of S. rebaudiana, proximate analysis were done on S. rebaudiana leaves from different maturity stage, i.e., before flowering (30-35days), flowering time (50-60 days) \& over mature (70- 90days) of new apical stem grown on 2 year old plant. Separation method by solvent extraction followed by crystallization and re- crystallization of rebaudioside A in amorphous form were done in order to obtain sweetener which consist mainly bioactive compound, rebaudioside A. Moisture, ash, reducing sugar, non-reducing sugar and total carbohydrate were found maximum in variety MSR007 before flowering stage with 8.45\%, 7.17\%, 4.45\%, 8.45\%, and 13.65\% respectively. Percentages of rebaudioside A were found maximum just before flowering stage with 3.45\% followed by over matured stage with 2.20\% and during flowering time with 1.82\%.
100. Attia, Ahmed E. and {EL-BAGOURy}, Olfat E. and Allam, Abdel-Wahab I. and {Abdel-Ghany}, Ashraf M., Effect of Propagation Method and Nitrogen Fertilization on Stevia (Stevia Rebaudiana. Bertoni) Yield and Quality in Egypt, Egyptian Journal of Agricultural Research, vol. 83, no. 3, pp. 1269--1291, September 2005. doi: 10.21608/ejar.2005.247597. Abstract
     Two field experiments were carried out in Giza Agricultural Station - Agricultural Research Center during the two successive seasons 2001j2002 and 2002j2003 to study the effect of propagation method (seed, tissue culture and root cuttings), nitrogen fertilization (0, 20 and 40 kg Nlfedlcut) and their interaction on Stevia rebaudiana yield and quality. Seeds of stevia variety Spanti imported from Spain and locally regenerated vegetatively were used to produce plantlets, root cuttings and shoot apex tissue culture. Results showed that tissue culture and root cuttings propagated plants were significantly taller than seed propagated plants. Tissue culture and root cutting propagation methods exceeded seed propagated plants in No. of branches j plant in first, second and fifth cuts. Root cutting propagated plants gave the maximum values of leaves fresh weight (2.7, 3.12, 1.55 and 1.58 t/fed for the first, second, third and fourth cuts, respectively). Plants propagated through root cuttings exceeded plants propagated by seed and tissue culture in stevioside \% in all cutting dates giving maximum value of 24.16\% in the first season and 21.14\% in the second season in the 5th cut respectively. Application of 40kg N/fed/cut gave significant maximum values of plant height in three cuts (54.06, 54.33 and 53.07cm. for first, second and fifth cuts, respectively). Nitrogen fertilization affected all cuts for the No. of branchesjplant and the application of either 20 or 40 kg N/fed/cut significantly exceeded 0 kg N/fed/cut. Application of 40 kg N/fed/cut gave maximum values of fresh leaves weight in all cutting dates (2.27, 2.86, 1.56, 1.56 and 3.37 tjfed respectively), meanwhile dry leaves weight yield gave (0.87, 0.96, 0.52, 0.52 and 1.13 tjfed. respectively). Application of 20 and 40 kg N/fedcut exceeded Okg N/fedlcut in stevioside \% in both seasons. Application of 40 kg Nlfed/cut for stevia plants propagated by root cutting produced maximum yield of dry leaves weights of 1.06, 1.13 and 0.54 t/fed. for first, second and fourth cuts, respectively. Therefore, total stevioside yield reached its maximum value (962.43 kg/fed/year) when root cutting propagation method and application of 40 kg N/fed/cut were used.
101. Behera, {\relax MS} and Mahapatra, {\relax PK} and Singandhupe, Ramlal and Kundu, Dilip and Barman, Dhananjay, Enhancing Yield and Water Use Efficiency of Stevia (Stevia Rebaudiana, Bertoni) through Drip Irrigation System, Journal of Indian Society of Coastal Agricultural Research, vol. 31, pp. 71--76, January 2014. Abstract
     A field experiment was conducted at the Research Farm of the Directorate of Water Management, Bhubaneswar (Odisha) during rabi seasons of 2005-06 and 2006-07 to study the effect of drip irrigation regimes and fertilizer levels on the performance of stevia (Stevia rebaudiana, Bertoni) in a sandy soil of acidic reaction. The treatments included three irrigation regimes (I1- drip irrigation at 100\% PE, I2 at 80\% PE and I3 at 60\% PE) and three fertility levels (F1-100\%, F2– 75\% and F3- 50\% recommended dose of 110-45-45 kg N-P2O5-K2O ha-1) with a control treatment having surface (furrow) irrigation and conventional soil application of fertilizer. Drip irrigation reduced consumptive use of water by 40\%, increased water use efficiency by 62\% and water productivity by 68\% compared to surface irrigation. Application of irrigation at 100\% pan evaporation (PE) with 100\% recommended dose of fertilizer produced 9,131 kg fresh or 2, 903 kg dry leaf per hectare. The consumptive use of water was 780 mm with water use efficiency 3.73 kg ha-mm-1 and water productivity Rs 746 mm-1.
102. Bolonhezi, D. and Khan, I. A. and Moraes, R. M., Biomass Yield of Stevia Rebaudiana Grown on Hydroponic Systems Using Different Nitrogen Rates, Planta Medica, vol. 76, no. 5, pp. P2, March 2010. doi: 10.1055/s-0030-1251764. Abstract
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103. Chumthong, B. and Detpiratmongkol, S., Effects of Different Types of Manures and Levels of Applications on Growth and Yield of Stevia (Stevia Rebaudiana), International Journal of Agricultural Technology, vol. 12, no. 7.1, pp. 1367--1373, 2016. url: https://www.thaiscience.info/Journals/Article/IJAT/10985311.pdf. Abstract
     Stevia (Stevia rebaudiana (Bertoni.) Hemsl.) is a medicinally important plant, a sweet herb and is a natural non caloric bio-sweetener, which offers a solution for complex diabetic problems and obesity in human. The objective of this study was to investigate the effect of two animal manures on growth of stevia. A pot experiment was conducted in the net house of Faculty of Agricultural Technology, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand, during July to November, 2011. A split plot in randomized complete block design with 4 replications was employed. Two organic manures (cow and chicken manures) and four rates of organic manure applications (6.25, 12.50, 18.75 and 25.00 ton ha-1) were as main plots and sub plots, respectively. The results disclosed that stevia applied with chicken manure gave significantly higher growth (such as stem, leaf and root dry weight and total dry weight) and leaf dry weight yield than those applied with cow manure. The 25.00 ton ha-1 of animal manure gave the highest of total dry weight and leaf dry weight yield while 6.25 ton ha-1 of animal manure gave the lowest. Increasing chicken manures rates increased growth and total dry weight of stevia. However, it may be concluded that the stevia crop may be applied with 25.00 ton chicken manure ha-1.
104. Chumthong, B. and Detpiratmongkol, S., Response of Biomass and Yield of Stevia (Stevia Rebaudiana Bertoni.) to Flower Removal, International Journal of Agricultural Technology, vol. 14, no. 7, pp. 1141--1146, 2018. url: http://www.ijat-aatsea.com/pdf/v14_n7_2018_%20December/15_IJAT_14(7)_2018_Chumthong,%20B.%20.pdf. Abstract
     It has never been reported on the effect of flower removal on the yield of Stevia plant. The effect of flower removal on growth and yield of Stevia was studied. Reesults revealed that flower removal produced significantly (P=0.05) greater number of leaves, dry biomass yield and leaf dry weight yield compared to the control. Four times of flower removal plant gave the highest number of leaves (1,318.50 plant-1), total biomass dry weight (11.31 g plant1-) and leaf dry weight yield (0.81 t ha-1) compared to the control. Therefore, flower removal during the production of Stevia plant should be practiced in order to increase growth and leaf yield.
105. Das, Kuntal and Dang, Raman and Shivananda, Thippenahalli Narayanappa and Sekeroglu, Nazım, Influence of Bio-Fertilizers on the Biomass Yield and Nutrient Content in Stevia Rebaudiana Bert. Grown in Indian Subtropics, Journal of Medicinal Plants Research, vol. 1, no. 1, pp. 005--008, August 2007. doi: 10.5897/JMPR.9000788. Abstract
     A pot culture experiment was conducted at Indian Institute of Horticultural Research, Hessaraghata, Bangalore, India to study the effect of bio-fertilizers on the biomass yield and NPK content in Stevia (Stevia rebaudiana ). The results show the yield and NPK content in stevia plant has been found to be increased initially and thereafter, the amount of the same decreased with the progress of plant growth up to 60 days with the combined treatment of bio-fertilizers rather than individual treatment. This is due to their ability to fix atmospheric nitrogen (symbiotic and asymbiotic) and transform native soil nutrients likely phosphorus, zinc, copper, iron, sulfur from the non-usable (fixed) to usable form and decompose organic wastes through biological processes which in turn releases nutrients in a form which can be easily assimilated by plants resulting in an increase in biomass production of stevia plant.
106. Das, K and Dang, R and Shivananda, T. N., Influence of Bio-Fertilizers on the Availability of Nutrients (N, P and K) in Soil in Relation to Growth and Yield of Stevia Rebaudiana Grown in South India, International Journal of Applied Research in Natural Products, vol. 1, no. 1, pp. 20--24, March 2008. url: https://www.researchgate.net/publication/43655804_Influence_of_bio-fertilizers_on_the_availability_of_nutrients_N_P_and_K_in_soil_in_relation_to_growth_and_yield_of_Stevia_rebaudiana_grown_in_South_India. Abstract
     Summary: A field experiment was conducted at Ripponpet (Dist. Karnataka), India in an acidic soil (pH 6.10) to study the response of Stevia plant by the application of bio-fertilizers. The results showed the amount of available nitrogen (N), phosphorus (P) and potassium (K) contents in soil have been found to increase significantly up to third month and thereafter, the amount of the same decreased with the progress of the plant growth up to sixth month irrespective of treatments. However, the results further envisaged that the total yield of fresh biomass has been recorded an increase up to sixth month, being highest in the combined application of biofertilizers over that of their corresponding sole applications. The percent increase of bio-mass yield was recorded highest (22.14\%) in the treatment when all the bio-fertilizers were applied together. Industrial relevance: The demand of Stevia is increasing widely due to its non caloric nature and usages as sugar supplement. The leaves are having commercial importance due to presence of di-terpene sweet glycosides which are 300-400 times sweeter than sugar without any side effects. The plant was domesticated in India in last 20th century from the wide source. So there is a need to set up certain protocols for cultivation of Stevia in various soil conditions so that farmers can be benefited by selling, and industries also can get healthy leaves throughout the year for isolate the active components and can formulate economical market products.
107. Das, Kuntal and Dang, Raman and Shivananda, T. N. and Sur, Pintu, Interaction Between Phosphorus and Zinc on the Biomass Yield and Yield Attributes of the Medicinal Plant Stevia (Stevia Rebaudiana), The Scientific World Journal, vol. 5, pp. 390--395, 2005. doi: 10.1100/tsw.2005.49. Abstract
     A greenhouse experiment was conducted at the Indian Institute of Horticultural Research (IIHR), Bangalore to study the interaction effect between phosphorus (P) and zinc (Zn) on the yield and yield attributes of the medicinal plant stevia. The results show that the yield and yield attributes have been found to be significantly affected by different treatments. The total yield in terms of biomass production has been increased significantly with the application of Zn and P in different combinations and methods, being highest (23.34 g fresh biomass) in the treatment where Zn was applied as both soil (10 kg ZnSO4/ha) and foliar spray (0.2\% ZnSO4). The results also envisaged that the different yield attributes viz. height, total number of branches, and number of leaves per plant have been found to be varied with treatments, being highest in the treatment where Zn was applied as both soil and foliar spray without the application of P. The results further indicated that the yield and yield attributes of stevia have been found to be decreased in the treatment where Zn was applied as both soil and foliar spray along with P suggesting an antagonistic effect between Zn and P.
108. Das, Kuntal, Interaction Effect Between Zn and P on the Yield Attributes and Content of Zn in Stevia Rebaudiana., July 2006. url: https://acs.confex.com/crops/wc2006/techprogram/P9442.HTM. Abstract
     A green house experiment was conducted at the Indian Institute of Horticultural Research, Hessaraghatta, Bangalore to study the interaction effect between Zn and P on the yield attributes and content of Zn in Stevia rebaudiana, a non caloric medicinal and natural.Therefore, the present investigation was undertaken to improve the yield as well as quality through the use of modern agro-techniques. The treatments used for the present investigation are T1, only soil (control, -P, -Zn); T2, Soil (control, +P, -Zn); T3, soil + ZnSO4 @ 10 kg ha-1 (-P); T4, ZnSO4 @ 0.2\% ha-1 foliar spray (-P); T5, soil + ZnSO4 @ 10 kg ha-1 + ZnSO4 @ 0.2\% ha-1 foliar spray (-P); T6, soil + ZnSO4 @ 10 kg ha-1 (+P); T7, ZnSO4 @ 0.2\% ha-1 foliar spray (+P); T8, soil + ZnSO4 @ 10 kg ha-1 + ZnSO4 @ 0.2\% ha-1 foliar spray (+P). The results show that the total weight of fresh, oven dried biomass and growth attributes have been found to be highest in the treatment T5 where ZnSO4 was applied as soil (10 kg ha-1) foliar (0.2 \%) combinedly, The content of Zn in plants was recorded highest in the treatment T4 where ZnSO4 at 0.2 \% was applied as foliar while that of the same content recorded lowest in the treatment T6 where Zn and P was applied combinedly. Key words : Interaction, P, Stevia, yield attributes, Zn.
109. Donega, M. A. and Cantrell, C. L. and Moraes, R. M. and Mello, S. C., Influence of Calcium on Biomass Production and Yield of Rebaudioside in Stevia Rebaudiana Plants, Planta Medica, vol. 79, no. 5, pp. P3, March 2013. doi: 10.1055/s-0033-1336445. Abstract
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110. {El-Sirafy}, Z. and Hassan, R. and {El-Shazly}, M. and Gad, M., Role of Bio and Organic Fertilizers in Reducing Some Chemical Fertilizers Doses on Yield of Stevia Plants Under Some Different Soil Types, Journal of Soil Sciences and Agricultural Engineering, vol. 6, no. 7, pp. 829--844, July 2015. doi: 10.21608/jssae.2015.42776. Abstract
     To study the influence of organic and bio fertilization compared with NPK fertilization and their interactions on yield of stevia plant (Stevia rebaudiana Bertoni) under some different Egyptian Soils Conditions was carried out a pot experiment at the Experimental Farm of the Fac. Agric. Mansoura Univ. during the summer season of 2013. The experimental design of present study was complete randomized block design with three replications, where soil types represent blocks and each block contains fertilization treatments. Three soil types were used as clay, saline and calcareous and six fertilization treatments are contained in each soil type as control, 100 \% of recommended NPK fertilizers,50 \% of recommended NPK fertilizers, biofertilizer, organic fertilizer (compost), and mixture of 50 \% of recommended NPK + bio + compost. Results indicated that application all fertilizer sources increased the means values of leaves, stems and shoot fresh weights (32.3, 39.7 and 72.0 g/pot) and the others treatments of fertilizers used (63.6, 60.4, 48.6 and 38.9 g/pot for the treatments of mixture, 50 \%, organic and biofertilizer, respectively). The corresponding values of increases over control due to the aforementioned respective treatments were 42.5, 34.1, 30.9, 19.1 and 9.0 g/pot. These increases represent the following percentages over control : 144.6, 115.6, 104.7, 64.7 and 30.5 \%, respectively. Also dry yield was (24.1, 23.1 and 47.2 g/pot) of stevia plants significantly than control (without fertilization). Concerning to soil types revealed that the greatest value was obtained due to growing stevia plants on clay soil compared to both saline and calcareous soils. The greatest shoots plant fresh weight of stevia was obtained due to growing in clay soil where the mean value was 64.3 g/pot. Both saline and calcareous soils were followed clay soil where the respective mean values of shoot plant fresh weight were 48.5 and 43.8 g/pot. While The highest shoot plant dry yield of stevia was obtained due to growing stevia plants on clay soil where the mean value was 43.2 g/pot. Both saline and calcareous soils were followed clay soil where the respective mean values of shoot plant fresh weight were 31.4 and 28.0 g/pot. In addition, all fertilizers treatments eliminated bad effect of both saline and calcareous soils in comparison with control (interaction effect).
111. Gayla, J. K. L. and Politud, E. R. R., Herbage Yield of Stevia (Stevia Rebaudiana Bert.) in Response to Doufos Granules, Organic Growing Media and Levels of Carbonized Rice Hull, 2017. url: https://agris.fao.org/search/en/records/6473b0c413d110e4e7a990be. Abstract
     Stevia rebaudiana Bert. is a native tropical plant from Brazil and Paraguay with therapeutic benefits. Its leaves produce a sweetener-stevioside which is 150-300 times sweeter than cane sugar. Investigation on herbage yield of Stevia in response to doufos granules an organic growing media, and levels of carbonized rice hull was conducted from November 2016 to January 2017 in Ornamental Green House of the College of Agriculture, University of Science and Technology of Southern Philippines. No significant difference was observed among treatments in terms of growth and herbage yield parameters. The plants growth in medium composed of 1/3 kg sand + 1/3 kg vermicast + 1/3 kg garden soil + 200 g carbonized rice hull had the most number of leaves (63.84), highest fresh leaf yield (19.67 g), highest fresh herbage (847.22 kg/ha), oven-dried leaf yield (152.78 kg/ha), highest fresh stem weight (21 g), lowest leaf curling incidence (1.67 counts), highest gross sales (Php 763,900.00/ha) and R0I (124.35\%) while planting in pure garden soil led to the least fresh herbage (506.65 kg/ha) and oven-dried leaf yield (97.49 kg/ha).
112. Hernández, Jaime L. and Combatt, Enrique M. and Jarma O., Alfredo and Polo S., Janer and Rodríguez P., Luis, Yield and Quality of Leaves of Stevia Rebaudiana Bert. Under Pedological Offer and Two Levels of Radiation in Five Colombian Regions, Revista U.D.C.A Actualidad \& Divulgación Científica, vol. 19, no. 1, pp. 77--85, June 2016. url: http://www.scielo.org.co/scielo.php?script=sci_abstract&pid=S0123-42262016000100009&lng=en&nrm=iso&tlng=es.
113. Jalili, Zahra and Ghamarnia, Houshang and Kahrizy, Danial, Investigating on the Effect of Shallow Saline Groundwater on the Stevia Yield, Water and Irrigation Management, vol. 8, no. 2, pp. 193--209, September 2018. doi: 10.22059/jwim.2018.264526.630. Abstract
     The use of shallow groundwater as a source of irrigation water can be used in different plains located in southern, northern, western and north western parts of country during most crops planting period. In this investigation Lysimetric experiments were conducted to determine the contribution made by groundwater to the overall water requirements of (Stevia Rebaudiana B.). The plants were grown in 36 columns, each having a diameter of 0.40 m and packed with silty clay soil. The three replicate randomized complete block factorial experiments were carried out using different treatment combinations. Nine treatments were applied by maintaining groundwater, with an EC of 1, 2, 6 and 10 dS/m, at three different water table levels (0.7, 0.9 and 1.20 m) with supplementary surface irrigation. The supplementary irrigation requirement for each treatment was applied by adding water (EC of 1 dS/m). The average percentage contribution from groundwater for the different treatments (1, 2, 6 and 10 dS/m) and water table depths (0.7, 0.9 and 1.2 meter) as (66.5, 57.7, 45.3) and (61.5, 52.7, 42.1) and (59.9, 49.4, 41.0) and (59.0, 46.6, 40.1) percent of the average annual (Stevia Rebaudiana B.) water requirement respectively. The overall results showed that the shallow ground water with quality less than 2 dS/m can be used to compensate a most part of the annual plant water requirement.
114. Jena, Pradeep Kumar and Goyal, Ashwani Kumar and Bhardwaj, Arvind, Growth Pattern and Biomass Yield of Stevia Rebaudiana (Bert.) Grown Under Polyhouse Conditions in Relation to Climate Change., Journal of Plant Development Sciences, vol. 3, no. 3 \& 4, pp. 317--320, 2011. url: http://jpds.co.in/wp-content/uploads/2019/07/21.-Pradeep.pdf. Abstract
     Climate change affects the earth‟s temperature, precipitation, hydrological cycles, frequency and intensity of heat waves and many extreme events, which has a great impact on agricultural production. On the wake of the climatic change, polyhouse farming is the only way to protect crops and manage a better yield than in normal climatic condition. It protects crops from wind, rain, radiation, and precipitation, etc again it facilitates the farmers not to depend on the monsoon for the cultivation but allow scheduling of the production according to the market needs.
115. Kaur, Gurdeep and Sudhakara Reddy, M., Influence of P-Solubilizing Bacteria on Crop Yield and Soil Fertility at Multilocational Sites, European Journal of Soil Biology, vol. 61, pp. 35--40, March 2014. doi: 10.1016/j.ejsobi.2013.12.009. Abstract
     Phosphate-solubilizing bacteria (PSBs) Pantoea cypripedii (PSB-3) and Pseudomonas plecoglossicida (PSB-5) isolated from organic field were studied for improvement of maize and wheat crop at multilocational sites with and without rock phosphate (RP) fertilization during two year of field study under different agroclimatic regions. Application of both the bacterial strains as bio-inoculants showed significant effect on maize and wheat grain yield and on soil fertility at all different agroclimatic regions. Grain yield, phosphorous (P) uptake, soil organic carbon, available P, enzyme activities and P-solubilizing bacterial population in all the experimental crop fields at different sites significantly increased due to inoculation. Improvement in crop yield and soil fertility at three different sites was more pronounced and significant when RP was supplemented along with seed inoculation compared to uninoculated control treatment. Present study results suggest that P.~cypripedii (PSB-3) and P.~plecoglossicida (PSB-5) along with RP fertilization play an important role in plant growth promotion and improvement of soil fertility in different agroclimatic regions.
116. Kaushik, Gaurav and Vishnu, Jadav and Arslan, Ranjan, The Outcome of Farmyard Manure and Nitrogen on the Yield and Nitrogen Uptake by Stevia (Stevia Rebaudiana Bertoni), International Journal of Manures and Fertilizers, vol. 3, no. 6, pp. 529--532, June 2014. doi: 10.46882/IJMF/1079. Abstract
     Two independent field experiments were conducted at Punjab Agricultural University, Ludhiana, Punjab, India in 2006 and 2007 in a loamy sand soil normal in soil reaction and electrical conductivity, low in organic carbon and available nitrogen, medium in phosphorus and potassium status in a complete randomized design with four replications to study the effect of different levels of farmyard manure (FYM) and nitrogen on the yield and nitrogen uptake of Stevia rebaudiana Bertoni. Four levels of farmyard manure (0, 15, 30 and 45 t/ha) and four levels of nitrogen (0, 20, 40 and 60 kg/ha) were tested. Biomass yield (kg leaves/ha) and several other yield parameters (dry leaf yield, number of leaves per plant, leaf area index and dry matter accumulation per plant) were highest in plants grown at the highest level of farmyard manure (45 t FYM ha-1). Maximum nitrogen uptake was also recorded under 45 t FYM ha-1 in both experiments. Plants grown at 40 and 60 kg N ha-1 produced significantly higher number of branches, number of leaves per plant, and showed higher leaf area index and nitrogen uptake compared to lower nitrogen levels. Dry leaf yield and dry matter accumulation per plant was highest at 60 kg N ha-1.
117. Khan, A. R. and Chowdhury, S. H. and Karim, M. M., Effect of Date of Planting on the Growth and Leaf Yield of Stevia (Stevia Rebaudiana), Journal of the Bangladesh Agricultural University, vol. 10, no. 2, pp. 205--210, 2012. doi: 10.3329/jbau.v10i2.14684. Abstract
     An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh from December 2009 to March 2011 to determine the effect of date of planting on growth and leaf yield of Stevia. The experiment comprised 24 dates of planting in the year of 2010 viz. 1 January (T1), 15 January (T2), 1 February (T3), 15 February (T4), 1 March (T5), 15 March (T6), 1 April (T7), 15 April (T8), 1 May (T9), 15 May (T10), 1 June (T11), 15 June (T12), 1 July (T13), 15 July (T14), 1 August (T15), 15 August (T16), 1 September (T17), 15 September (T18), 1 October (T19), 15 October (T20), 1 November (T21), 15 November (T22), 1 December (T23) and 15 December (T24). The experiment was laid out in a Complete Randomized Design with three replications. Twenty four dates of planting were included in the experiment in 72 earthen pots (24 X 3) of 30 cm diameter X 30 cm height. Stem cuttings were placed in shaded seed bed for root initiation. Twenty one - day old stem cuttings were used as planting material. Stem cuttings were transplanted in the pots on the specific dates. Different dates of planting had significant effect on the growth and yield parameters. 1 April 2010 (T7) planting proved to be the superior to the other treatments i.e. plant height (68.50cm), number of leaves plant-1 (142.33), number of primary branches plant-1 (37.33), fresh weight of leaves plant-1 (14.11g), fresh weight of primary and secondary branches plant-1 (11.06g and 20.91g), dry weight of leaves plant-1 (3.38g) which might be due to warm environmental conditions like clear sunshine and high temperature. The overall results suggested that stevia seedlings may be planted from 15 February to 30 April for better yield of leaves. DOI: http://dx.doi.org/10.3329/jbau.v10i2.14684 J. Bangladesh Agril. Univ. 10(2): 205-210, 2012
118. Khanom, S. and Saha, B. K. and Islam, M. T. and Chowdhury, M. a. H., Influence of Organic and Inorganic Fertilizers on the Growth, Leaf Yield, Chlorophyll and Protein Contents of Stevia Grown in Different Soil Types, Progressive Agriculture, vol. 19, no. 1, pp. 23--31, 2008. doi: 10.3329/pa.v19i1.16986. Abstract
     A pot experiment was conducted in the open net house of the Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh from January to June, 2007, to study the effect of organic and inorganic fertilizers on the growth, leaf yield, chlorophyll and protein contents of Stevia rebaudiana (Bert.). The experiment was laid out in completely randomized design with three replications having 16 treatment combinations. Four types of soil viz., saline, acidic, calcareous and non-calcareous soils were collected from Khulna, Tangail, Natore and Mymensingh districts of Bangladesh, respectively. Two organic (poultry manure and cow dung) and one inorganic fertilizers @ the recommended dose along with a control were used as treatment factor. The experimental results indicated that different soil types significantly influenced all parameters studied. The highest values of all parameters were obtained from the plant grown in noncalcareous soil which was identical with acidic soil for some parameters. Different types of organic and inorganic fertilizer had also significant influence on all plant parameters. In all cases, the highest values were recorded from the plant fertilized with chemical fertilizers. Poultry manure and cow dung also showed identical results with chemical fertilizer in most cases. Interaction effect of different types of soil and fertilizer showed significant variation for most of the parameters studied except chlorophyll and protein contents. Plants grown in noncalcareous soil fertilized with chemical fertilizers exhibited the best performance in most of the cases. The overall results suggested that stevia can be cultivated in noncalcareous and acidic soils fertilized with chemical fertilizers along with poultry manure favoring the productivity of stevia.DOI:~http://dx.doi.org/10.3329/pa.v19i1.16986 Progress. Agric. 19(1): 23 - 31, 2008
119. Kipa, Prabha R and Prathap, Laxmisagar M and Singh, Vinod, Nutrient Composition in (Stevia Rebaudiana) Bert. Grown in Indian Sub-Tropics and Influence of Bio- Fertilizers on the Biomass Yield, International Journal of Manures and Fertilizers, vol. 2, no. 1, pp. 250--252, January 2013. doi: 10.46882/IJMF/1044. Abstract
     A pot culture experiment was conducted at Indian Institute of Horticultural Research, Hessaraghata, Bangalore, India to study the effect of bio-fertilizers on the biomass yield and NPK content in Stevia (Stevia rebaudiana). The results show the yield and NPK content in stevia plant has been found to be increased initially and thereafter, the amount of the same decreased with the progress of plant growth up to 60 days with the combined treatment of bio-fertilizers rather than individual treatment. This is due to their ability to fix atmospheric nitrogen (symbiotic and asymbiotic) and transform native soil nutrients likely phosphorus, zinc, copper, iron, sulfur from the non -usable (fixed) to usable form and decompose organic wastes through biological processes which in turn releases nutrients in a form which can be easily assimilated by plants resulting in an increase in biomass production of stevia plant.
120. Kochetov, A A, Growth and Yield of Stevia Rebaudiana Bertoni under Different Conditions of Lighting, pp. 197--199, October 2004. url: https://www.researchgate.net/publication/285525506_AA_Kochetov_Growth_and_yield_of_Stevia_rebaudiana_Bertoni_under_different_conditions_of_lighting_Innovation_towards_modernized_agriculture_Selangor_October_04-07_2004_P197-199. Abstract
     The photoperiod and the intensity of irradiation have been shown to be basic factors, determining the growth and yield of Stevia plants in controlled condition. The optimal lighting range has been determinate. The regressive correlation between the dry mass accumulation and the intensity of lighting has been derived. The most economic regimes are determined for cultivation Stevia plants under artificial light conditions.
121. Kumar, M E Charan and Gaval, A Rajesh and Rathod, Pradeep and Chandregowda, M, Effect of Organic Manures and Bio-Fertilizers on Growth and Yield of Stevia (Stevia Rebaudiana) - Proquest, Journal of Ecobiology, vol. 29, no. 2, pp. 81--88, 2011. url: https://www.proquest.com/openview/104b9f39a3bda659710321f3d1a045ac/1?pq-origsite=gscholar&cbl=1136338. Abstract
     An investigation on the effect of organic manures and bio-fertilizers on growth and yield of Stevia (Stevia rebaudiana Bert.) revealed that application of 50 \% of recommended dose of nitrogen through vermicompost (basal) + 50 \% of nitrogen through neem cake (top dressing) + bio-fertilizers resulted in significantly higher plant height (36.7 cm), maximum plant spread (840.6 cm2), maximum number of branches (39.3) per plant and total dry matter accumulation (16.2 g plant-1), maximum fresh weight of leaves [46.4 g plant-1 \& 4581.7 kg ha-1], dry weight of leaves [13.4 g plant-1 \& 1318.51 kg ha-1].
122. Kumar, R and Sood, S and Sharma, S and Kasana, R C and Pathania, V L and Singh, B and Singh, R D, Effect of Plant Spacing and Organic Mulch on Growth, Yield and Quality of Natural Sweetener Plant Stevia and Soil Fertility in Western Himalayas, International Journal of Plant Production, 2014. Abstract
     The use of leaf mulch as a soil cover is effective in improving yield and soil fertility. The field experiment was conducted during 2010 and 2011 to study the effect of plant spacing (30 cm × 30 cm and 45 cm × 30 cm) and four mulches \{pine needles (Pinus roxburghii), poplar leaf (Populus deltoides), silver oak (Grevillea robusta) tree leaf mulch and unmulched control\} on growth, yield, quality of stevia and soil fertility. Weed count and dry weed weight was not affected by spacing levels during August and at the time of harvest, whereas, in unmulched plots it was significantly higher than mulched plots. Dry leaf yield, total dry biomass and leaf area index (LAI) were significantly higher in 30 cm × 30 cm spacing level and poplar leaf mulch. All the mulched plots significantly increased organic carbon (OC), available nitrogen (N), phosphorus (P) and potassium (K), bacterial and fungal population compared to unmulched plots. Rebaudioside-A content was higher in plots mulched with poplar leaves. Steviol glycosides were not significantly affected by different treatments. Soil biological activities were also enhanced by tree leaf mulches. Leaf mulch enhanced microbial biomass, relative to non-mulched soils, likely via improving C and water availability for soil microbes.
123. Kumar, Rakesh and Sharma, Saurabh and Sharma, Mohit, Growth and Yield of Natural-Sweetener Plant Stevia as Affected by Pinching, Indian Journal of Plant Physiology, vol. 19, no. 2, pp. 119--126, June 2014. doi: 10.1007/s40502-014-0085-8. Abstract
     Leaf is the main economic part of stevia plant (Steviarebaudiana Bertoni), hence production of more leaf biomass with higher steviol glycosides is the main criterion for crop performance. A field experiment was conducted during 2009 and 2010 to assess the effect of pinching on growth, yield and quality of stevia. The experiment consisted of eight treatments of pinching; six treatments were executed at 20, 30 and 40~days after transplanting (DAT) at 10 and 20~cm height (main branches only), one at 40 DAT (main~+~secondary branches) at 20~cm height and one control (no pinching). The experiment was conducted using a randomized complete-block design with three replications. Pinching treatments significantly affected number of leaves, branches per plant, plant spread and leaf yield, as compared with the control. Stevia plants pinched at 40 DAT (main~+~secondary branches) at 20~cm height recorded significantly higher number of leaves plant−1 (213), fresh leaf weight (93.8~g plant−1) at first harvest and 27.7~\% higher total leaf dry biomass as compared with control. This treatment also recorded higher net returns (Rs. 1,86,998~ha−1) and benefit-cost (B:C) ratio because of higher production of leaf biomass as compared with other treatments. Steviol glycosides (stevioside and rebaudioside–A) were not affected significantly by pinching treatments. Interaction effects of years and pinching treatments were significant for all the growth traits and yield during both the harvests. We conclude that pinching enhances leaf biomass and profits in stevia.
124. Kumar, Rakesh and Sharma, Saurabh and Prasad, Ramdeen, Yield, Nutrient Uptake, and Quality of Stevia as Affected by Organic Sources of Nutrient, Communications in Soil Science and Plant Analysis, vol. 44, no. 21, pp. 3137--3149, November 2013. doi: 10.1080/00103624.2013.832285. Abstract
     A field experiment was conducted during 2008 and 2009 at the Council of Scientific and Industrial Research-Institute of Himalayan Bioresource Technology, Palampur, India, to study the effect of organic sources of nutrient on yield, nutrient uptake, fertility status of soil, and quality of stevia crop in the western Himalayan region. The experiment comprised eight different combinations of organic manure [farmyard manure (FYM), vermicompost (VC), and apple pomace manure (AP)]. Total leaf dry biomass increased by 149\% over the control with application of VC 1.5 t ha−1 + AP 5 t ha−1. Application of organic manures enhanced organic carbon and available nutrient status of soil more than the control. Nitrogen (N) and phosphorus (P) content in stem were significantly affected by the application of organic manures over the control. Stevia plants supplied with FYM 10 t ha−1 + AP 2.5 t ha−1 recorded more total glycoside than other treatments. Stevioside yield (kg ha−1) was greater with application of FYM 10 t ha−1 + AP 2.5 t ha−1.
125. Kumari, Shivani and Ghosh, Gautam and Meshram, M.R., TSS, Yield and Energetics of Stevia as Influenced by Nitrogen Levels and Spacing under Eastern U.P. Conditions, Agricultural Science Digest - A Research Journal, no. Of, March 2021. doi: 10.18805/ag.D-5199. Abstract
     Background: Stevia is a natural sweetener plant with zero calorie content which is used as an alternative source of sugar. Stevioside extract from stevia is considered to be 300-350 times sweeter than sugar. It is safe for use by both diabetics and hypo glycaemics due to its low glycaemic index.Stevia has some bitter aftertaste along with sweetness due to the presence of some essential oils, tannins and flavonoids.
126. Lal, R K and Chandra, R and Gupta, M M and Singh, A K and Singh, Manju and Verma, R K and Misra, H O and Kalra, A and Gupta, A K and Lal, C and Singh, H P and Kumar, B and Singh, H N and Shankar, H and Dhawan, O P and Krishna, A and Bansal, K and Rizvi, Hena and Bansal, R P and Chauhan, H S and Singh, S and Zaim, Mohd and Bahl, J R and Pandey, R, Registration of a High Yielding Variety CIMAP Madhu of Stevia, Journal of Medicinal and Aromatic Plant Sciences, vol. 33, no. 1, pp. 77--80, 2011. url: https://www.researchgate.net/publication/288921395_Registration_of_a_high_yielding_variety_CIMAP_MADHU_of_Stevia_Stevia_rebaudiana_Bert. Abstract
     Stevia (Stevia rebaudiana Bert.) of Family Asteraceae, also known as sweet herb or honey leaf, is the only natural sweetener in the world. Stevia is native to northeastern Paraguay. Stevia powder is extracted from the leaves of the plant and refined powder has been rated at 200 to 350 times sweeter than sugar. The medicinal uses of stevia are as a natural sweetener for diabetics, treating, obesity, hyperactivity, hypertension, carbohydrate cravings, tobacco and alcohol cravings, hypoglycaemia, indigestion, yeast infections, skin toning and healing. Its consumption is very high in Japan, Korea and China making upto 90\% of the world’s consumption. Under the genetic improvement programme of stevia by applying half sib family selection followed by cloline breeding approach, elite plants were selected on the basis of their performance in different field evaluation trials for high herb type quality- high steveoside, rebaudioside with low dulcoside -A content. CIMAP Madhu was found to highly promising for high fresh and dry leaf yield (4.3 t) with high steveoside (12.57\%), rebaudioside (5.8\%) with low Dulcoside –A content (0.2) and less pungent stevia leaves/powder against check (herb yield 2.6 t/ha, stevioside 3.63, rebaudioside 3.32 and dulcoside 3.69\%). The variety CIMAP Madhu of stevia has been developed by CIMAP through intensive breeding efforts. This variety will find direct utility in pharmacological/medical industries.
127. Lavini, Antonella and Riccardi, Maria and Pulvento, Cataldo and Luca, Sergio De and Scamosci, Michela and {d’Andria}, Riccardo, Yield, Quality and Water Consumption of Stevia Rebaudiana Bertoni Grown under Different Irrigation Regimes in Southern Italy, Italian Journal of Agronomy, vol. 3, no. 2, pp. 135--143, June 2008. doi: 10.4081/ija.2008.135. Abstract
     Stevia rebaudiana Bertoni is a herbaceous perennial plant originating in the north-east of Paraguay. Its leaves contain low-calorie sweetening agents that can be used as a natural alternative to artificial sweeteners. The leaves are consumed in special human diets and for the treatment of various diseases. The aim of the present work is to study water consumption, yield potential and quality characteristics of this species under different irrigation levels in southern Italy. The field work was carried out in 2006-2007. Irrigation treatments consisted of a control (T100), irrigated with 100\% restitution of water consumption and two treatments that received a water depth of 33\% (T33) and 66\% (T66) of treatment T100. Watering volume was estimated to replenish the soil profile to field capacity for a depth of 0.40 m. The crop was harvested twice a year, and agronomic performance as well as the major cation and glycoside contents (stevioside and rebaudioside A) were evaluated. Overall, the crop coefficients were similar between the two years, although in each year the second growing period showed higher values due to the higher evaporative demand of this period. Interactions of years with irrigation treatments and harvest time were not significant either for yield or yield components. In both cuts the T100 treatments achieved 40\% higher leaf dry yield than T33, while T66 showed intermediate values. The harvest index and water use efficiency showed no differences between the two cuts for the same treatments, while the values of both indices decreased with the increase in irrigation regime. Stevioside, rebaudioside A and cation content in the leaves were unaffected by irrigation regime. In order to develop the field cultivation of this species, field experiments are required to prepare a cultivation protocol as well as a genetic improvement program to develop varieties that better respond to the local environment.
128. Maniruzzaman, Md and Chowdhury, Tanzin and Rahman, Md Arifur and Chowdhury, Md Akhter Hossain, Potassium Requirement for Leaf Biomass Yield and K Nutrition of Stevia, Fundamental and Applied Agriculture, vol. 2, no. 3, pp. 297--302, September 2017. doi: 10.5455/faa.276431. Abstract
     Potassium (K) is an essential plant nutrient affecting most of the biochemical and physiological processes. It is classified as a macronutrient due to large quantities being taken up by plants during their life cycle. With the aim of establishing a scientific basis of K fertilization on the growth, leaf production, minimum K requirement and critical leaf K concentration of stevia, a pot experiment was carried out in the net house of the Department of Agricultural Chemistry, Bangladesh Agricultural University. Six levels of K viz. 0 (K0), 50 (K50), 100 (K100), 150 (K150), 200 (K200) and 250 (K250) kg ha-1 were used in acid and non- calcareous soils. Plants were harvested at 60 days after planting (DAP). Results showed that K application significantly influenced the growth attributes, leaf yield and other parameters. Highest values of most of the parameters were obtained at 200 kg K ha-1. Dry weight of stevia leaves at harvest was increased from 0.77-7.41g and 0.99-7.74g Pot-1 in acid and non-calcareous soils, respectively over control. Potassium content was directly proportional with the increased levels of K though uptake did not follow the same trend. Leaf critical K content was estimated to be ca 1.75 and 1.71\% in the plants grown in acid and non-calcareous soils, respectively. The minimum K requirement for maximum leaf biomass production (80\%) of stevia was also estimated to be ca 220 and 199 kg ha-1 grown in acid and non-calcareous soils, respectively. This study would contribute to improve K fertilization of stevia in various types of soil.
129. Martini, Andrea and Tavarini, Silva and Luciano, Avio and Sbrana, Cristiana and Giovannetti, Manuela and Angelini, Luciana Gabriella, Impact of Arbuscular Mycorrhizal Fungi (AMF) and Phosphorus Fertilization On Stevia (Stevia Rebaudiana Bertoni) Growth, Yield and Steviol Glycosides., vol. 1, pp. 101--114, 2016. url: https://arpi.unipi.it/handle/11568/813007. Abstract
     This study aims to evaluate the effect of Arbuscular Mycorrhizal Fungi (AMF) symbiosis and phosphorus fertilization on stevia growth, yield and steviol glycosides (SVglys) content and composition. Six treatments have been compared in a pot trial, testing three phosphorus doses (0, 25 and 50 mg P2O5/kg of soil) in plants with and without AMF (control). Rhizoglomus intraradices has been used as inoculum. Aboveground and belowground samplings have been done at 89 and 123 d after transplanting (DAT) for quantifying the main biometric characteristics, plant biomass and SVglys. R. intraradices successfully established mycorrhizal symbioses, with root colonisation above 75 \% in inoculated plants. At both sampling dates, mycorrhizal inoculation influenced plant height and branch number, independently of P level, with AMF-treated plants characterised by lower stem height and increased branching. At 123 DAT, inoculated plants showed a leaf dry yield higher than control (+16 \%). On the other hand, stem dry yield and below-ground biomass were not significantly influenced by AMF, while P fertilization seemed to be the main factor affecting their production level. A clear effect of AMF was evident in leaf SVglys content and composition at 89 DAT, with highest values in AMF-treated plants. Interestingly, in all P-treated plants Dulcoside A and Rebaudioside B could be detected, but not in control leaves. In plants harvested at 123 DAT, AMF positively influenced the total SVglys content only of treated plants grown without phosphorus (0P). Anyway, at 123 DAT, AMF-treated plants showed the highest yield (g plant-1) of Stevioside, Rebaudioside A and C, as a consequence of the enhanced leaf production. In conclusion, this study showed that AMF symbiosis could represent a valid biofertilization strategy to improve biomass in stevia, since AMF, in association with P supply, increased stevia leaf production and SVglys content, even if it was not possible to define a clear trend for all the analysed parameters.
130. Miyazaki, Y. and Watanabe, H. and Watanabe, T., Studies on the cultivation of Stevia rebaudiana Bertoni. III. Yield and stevioside content of 2-year-old plants, Eisei Shikenjo hokoku. Bulletin of National Institute of Hygienic Sciences, 1978. url: https://pubmed.ncbi.nlm.nih.gov/750051/. Abstract
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131. Moraes, R. M. and Donega, M. A. and Cantrell, C. L. and Mello, S. C., Yield of Diterpene Glycosides from the Leaves of Stevia Rebaudiana: A Specialty Crop for Mississippi, Planta Medica, vol. 79, no. 5, pp. P4, March 2013. doi: 10.1055/s-0033-1336446. Abstract
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132. Mostafa, Horia Sh., Impact of NPK Fertilization and Lithovit Rates on Growth, Yield Components and Chemical Constituents of Stevia Rebaudiana Bert. Plant, Middle East Journal of Applied Sciences, vol. 9, no. 2, pp. 412--420, 2019. url: http://w.curresweb.com/mejas/mejas/2019/412-420.pdf. Abstract
     In order to investigate the effect of NPK fertilization rates (0.0, 50, 75 and 100 of recommended rate), lithovit concentrations (0.0, 0.5 and 1.0 g/liter) and their combinations on Stevia rebaudiana growth and productivity, two field experiments were done. This trial was carried out at Experimental Farm (Ghazala), Fac. Agric., Zagazig University, Egypt, during the two consecutive summer seasons of 2017 and 2018. The recommended rate (RR) of NPK was 60, 30 and 50 kg/fed. as N, P2O5 and K2O, respectively. The obtained results demonstrated that the maximum values of plant height, branch and leaf number/plant, fresh and dry weight of leaves/plant, fresh yield of leaves/fed., fresh and dry weights of herb/plant, dry yield of herb/fed., total N, P and K and total sugars percentages as well as total chlorophyll content (SPAD unit) and active ingredients were detected when plants were applied with the highest concentration of lithovit and fertilized with 100\% RR of NPK compared to the other combinations under study. The main glycosides of Stevia rebaudiana leaves as detected by high performance liquid chromatography-mass spectrometry (LC-MS) were Rebaudioside A, Rebaudioside B, Rebaudioside C, Rebaudioside D, Rebaudioside E, Dulcoside A and Steviolbioside.
133. {Noor-E-Ferdous}, Rawnak Ara and Roy, Balaram and Sarker, Bikash C and Islam, Shariful, Effects of Different Cultivation Methods on Growth, Yield and Nutrient Content of Stevia, International Journal of Agriculture and Medicinal Plants, vol. 2, no. 4, pp. 10--18, 2021. url: https://www.researchgate.net/publication/361421823_Effects_of_different_cultivation_methods_on_growth_yield_and_nutrient_content_of_stevia. Abstract
     The experiment was conducted to study the effects of different cultivation methods on growth, yield and nutrient content of stevia at the experimental farm of Bangladesh Sugarcrop Research Institute, Pabna, Bangladesh. The treatments were T1: Field cultivation, T2: Under mango tree cultivation and T3: Pot cultivation. The experiment was laid out in Complete Randomized Design (CRD) with five (5) replications. Data were recorded on the following parameters plant height (cm), number of branch plant-1, number of leaves plant-1, leaf area plant-1 (cm2), fresh weight plant-1 (g), dry weight plant-1 (g), fresh leaf yield plant-1 (g), dry leaf yield plant-1 (g), N (\%), P (\%), K (\%), S (\%), Ca (\%), Mg (\%) and Zn (µg g-1) contents of Stevia leaf. Significant different was recorded among different cultivation methods. Significantly the highest plant height was obtained in T2 (under mango tree cultivation) treatment (127.93 cm) at 147 DAT. The highest primary and secondary branches at 147 DAT were recorded in T1 (field cultivation) treatment (12.72) and (31.83), respectively. The number of leaf plant-1 and leaf area plant-1 of stevia were significantly influenced by different cultivation methods and the highest was recorded in T1 treatment. The highest fresh weigh (165.92 g plant-1) and dry (44.15 g plant-1) plant-1 were obtained from T1 treatment. Significantly the highest fresh leaf yield (91.37 g plant-1 and 4512.12 kg ha-1) and dry leaf yield (24.83 g plant-1and 1226.17 kg ha-1) were obtained from T1 treatment also. The N content in stevia leaf ranged from 1.62 to 1.71\%. The highest (0.128\%) and the lowest (0.085\%) Phosphorus content was obtained in T1 and T2 treatment, respectively. The K content in stevia leaf ranged from 0.13 to 0.14\%. The highest Sulphur content was recorded in T1 treatment (0.25\%).The Ca and Mg content in stevia leaf ranged from (1.12 to 1.24\%) and (0.102 to 0.104\%), respectively. The highest Zn content was recorded in field cultivation (62.87 µg g-1). Results indicated the strong possibilities of field cultivation of stevia in Bangladesh.
134. Novak, B. and Benko, B. and Spicnagel, A.M. and Fabek, S. and Mesic, M., Yield, Nitrate and Steviol Content of Stevia (Stevia Rebaudiana Bertoni) Leaves as Affected by Fertilization Rate, Acta Horticulturae, no. 939, pp. 249--254, November 2012. doi: 10.17660/ActaHortic.2012.939.32.
135. Parris, Cheryl A. and Shock, Clinton C. and Qian, Michael, Soil Water Tension Irrigation Criteria Affects Stevia Rebaudiana Leaf Yield and Leaf Steviol Glycoside Composition, HortScience, vol. 52, no. 1, pp. 154--161, January 2017. doi: 10.21273/HORTSCI11352-16. Abstract
     Stevia (Stevia rebaudiana Bertoni) is of interest for the production of steviol glycosides due to their noncaloric sweetening properties. Commercial stevia leaf production to date has focused on rebaudioside A and stevioside. Relatively little is known about the cultural practices necessary for the efficient production of stevia leaf and steviol glycosides. Irrigation management is an important agronomic technique that growers can use to obtain high yield while also pursuing water use efficiency (WUE). This trial investigated the effect that irrigation onset criteria measured as soil water tension (SWT) had on dry stevia leaf yields, steviol glycoside content and yield, and steviol glycoside ratios. Two stevia cultivars, SW 107 and SW 129 (S\&W Seed Company Inc., Fresno, CA), were subjected to SWT irrigation criteria of 10, 20, 40, 60, and 80 kPa over a 57-day trial period at the Oregon State University (OSU) Malheur Experiment Station, Ontario, OR. Harvested plant material was evaluated for dry leaf yield and content of several steviol glycosides. Analysis of variance (ANOVA) showed significant cultivar differences in leaf yield, leaf stevioside and rebaudioside A content and yield, and steviol glycoside ratios (P = 0.05). Examining the data by ANOVA, dry leaf yield, stevioside percent, rebaudioside C percent, total steviol glycoside (TSG) percent, rebaudioside C yield, and TSG yield were significantly greater among the wetter (closer to 10 kPa) compared with the drier (closer to 80 kPa) SWT criteria treatments, yet a preferred treatment regime was not clearly evident. When comparing cultivars by regression analysis, there was a highly significant decrease in the stevioside content, and an increase in the ratio of rebaudioside A to stevioside from wetter to drier irrigation onset criteria (due to lower stevioside), whereas the rebaudioside A content did not respond significantly to differing irrigation criteria. Increasing dry leaf productivity with wetter irrigation criteria (closer to 10 kPa), directly increased the total rebaudioside A yield also, which in turn could provide increased crop value to the grower. Irrigating near 10 kPa produced higher dry leaf yield and total rebaudioside A yield, than irrigating at drier criteria.
136. Pude, R. and {Schmitz-Eiberger}, M. and Noga, G., Development, Yield and Selected Contents of Stevia Rebaudiana, Zeitschrift für Arznei- und Gewürzpflanzen, no. 1, pp. 37--43, 2005. url: https://pub.h-brs.de/frontdoor/index/index/docId/5199.
137. Rashid, Zahida and Rashid, Mudasir and Inamullah, Suhail and Rasool, Souliha and Bahar, Fayaz Ah, Effect of Different Levels of Farmyard Manure and Nitrogen on the Yield and Nitrogen Uptake by Stevia (Stevia Rebaudiana Bertoni), African Journal of Agricultural Research, vol. 8, no. 29, pp. 3941--3945, August 2013. doi: 10.5897/AJAR2013.6819. Abstract
     Two independent field experiments were conducted at Punjab Agricultural University, Ludhiana, Punjab, India in 2006 and 2007 in a loamy sand soil normal in soil reaction and electrical conductivity, low in organic carbon and available nitrogen, medium in phosphorus and potassium status in a complete randomized design with four replications to study the effect of different levels of farmyard manure (FYM) and nitrogen on the yield and nitrogen uptake of Stevia rebaudiana Bertoni. Four levels of farmyard manure (0, 15, 30 and 45 t/ha) and four levels of nitrogen (0, 20, 40 and 60 kg/ha) were tested. Biomass yield (kg leaves/ha) and several other yield parameters (dry leaf yield, number of leaves per plant, leaf area index and dry matter accumulation per plant) were highest in plants grown at the highest level of farmyard manure (45 t FYM ha-1). Maximum nitrogen uptake was also recorded under 45 t FYM ha-1 in both experiments. Plants grown at 40 and 60 kg N ha-1 produced significantly higher number of branches, number of leaves per plant, and showed higher leaf area index and nitrogen uptake compared to lower nitrogen levels. Dry leaf yield and dry matter accumulation per plant was highest at 60 kg N ha-1.
138. Rashwan, Basma and Ferweez, H., Effect of Mineral Nitrogen Fertilization and Compost on Stevia Yield and Its Profitability., Journal of Soil Sciences and Agricultural Engineering, vol. 8, no. 6, pp. 215--222, June 2017. doi: 10.21608/jssae.2017.37379. Abstract
     Stevia (Stevia rebaudiana Bertoni) was recently introduced to Egyptian agriculture in order to produce a natural sweetener (Steviol glycosides ) instead of sugar (Sucrose) to cover some of the lack of sugar production, which reached annually about 0.8 million ton. So, a field experiment was carried out at Mallawi Agriculture Research Station , Minia Governorate , Egypt, during two successive seasons (2014 and 2015) to study the effect of different levels of mineral N fertilization and compost on yield and its quality of stevia (Stevia rebaudiana Bertoni) under Middle Egypt conditions. The experimental design was a split plot in three replicates and the main plot were devoted N fertilizer levels ( 40, 60 and 80 kg N fed-1) while compost levels (0, 3 and 6 ton fed-1) were allocated in the sub plot. The obtained results revealed that N fertilizer level and/or compost level had a significant effect on plant height (cm) , fresh and dry leaves weight (g plant-1) , N, P\& K contents of stevia leaves and N uptake kg fed-1, dry leaves yield kg fed-1 , stevioside (St \%), rebaudioside A (Rb\%), stevioside yield (kg/fed) and rebaudioside A yield (kg fed-1), the remained nutrients ( N,P \& K (ppm) and OM \% ) in the soil post-harvest of stevia in two growing seasons, except P\% of leaf in the 2nd season for N fertilization. A significant interaction was scored between N fertilizer level and compost rate with regard to plant height (cm) , fresh and dry leaves weight (g plant-1) , N \% of stevia leaves and N uptake kg fed-1 , dry leaves yield kg fed-1 , stevioside (St \%), rebaudioside A (Rb\%), stevioside yield (kg fed-1) and rebaudioside A yield (kg fed-1) of steviain the two growing seasons. From the present study , it may be concluded that the application of 60 kg mineral N fertilizer + 6.0 ton compost fed-1 was the best treatment for improving the yield and quality of stevia and is advisable to achieve the highest values of rebaudioside A (298.99 and 297.74 kg fed-1) ,and net profit of stevia.
139. Rosnani, A G and Halim, R A and Yusop, M K and Shukri, M A Mohd, Effects of Rate and Application Frequency of Nitrogen Fertiliser on Biomass Yield and Sweetness Quality of Stevia (Stevia Rebaudiana Bertoni), Journal of Tropical Agriculture and Food Science, vol. 44, no. 2, pp. 305--313, 2016. url: http://jtafs.mardi.gov.my/jtafs/44-2/stevianew.pdf. Abstract
     Human life styles have changed so much and awareness on the use of sugar or sweeteners has become an integral part in our daily diet. Sweeteners which are high in calorie like white sugar, brown sugar, corn syrup, maple syrup, molasses and fruit syrups found in natural and processed are hazardous to our health. Stevia is very popular and ideal to substitute sugarcane. A study was conducted to determine optimum nitrogen (N) level and fertiliser application frequency (A) for high biomass yield and sweetness quality (content, yield, ratio) of stevia. A total of seven different levels of N and two application frequencies (after every harvest, A1 and after every two harvest, A2) were tested. Results indicated that biomass yield escalated with increased level of N up to 250 kg N/ha. At this level, total dry matter yield from four times of the harvesting frequency was 6 t/ha. There were interaction between N and A on glycoside content and glycoside yield of stevia. The maximum stevioside (St) content was about 85 mg/g at A2, under control treatment (0 N). Meanwhile, the maximum rebaudioside-A (Reb-A) content was 25 mg/g, better at A1 when plant treated with 40 kg N/ha as compared with A2. The St and Reb-A yield were better with application of 210 kg N/ha and 170 kg N/ha, respectively, at A2. Sweetness index of stevia was calculated by ratio of Reb-A to St because Reb-A possess the sweetest compound in stevia. It was found that application of N fertiliser at 50 kg/ha and at A1, the sweetness of stevia was high with the ratio of Reb-A to the St of 0.4.
140. High-Yield Cultivation Techniques of Stevia Rebaudiana (Bertoni) Hemsl. in Gannan Area of Jiangxi Province, Asian Agricultural Research, 2018. doi: 10.22004/ag.econ.279507. Abstract
     In order to expand the production of Stevia rebaudiana (Bertoni) Hemsl., the main points of high-yield cultivation techniques of a two-year-old stevia cultivar Shoutian No.3 in Gannan area of Jiangxi Province were summarized: cutting and transplanting in early spring; fine management, applying more basic and additional fertilizers and retaining stubbles two times in summer, retaining roots for seeding in late autumn, and mulching membrane for safe overwintering in winter. This study will provide certain guidance for the planting of S. rebaudiana in Ganzhou, Jiangxi Province
141. Sheu, B. W. and Tamai, F. and Motoda, Y., Effects of boron on the growth, yield and contents of stevioside and rebaudioside A of Kaa He-e (Stevia rebaudiana Bertoni), Journal of Agricultural Science - Tokyo Nogyo Daigaku (Japan), 1987. url: https://agris.fao.org/search/en/records/6471c79577fd37171a6f31b7. Abstract
     AGRICULTURAL SCIENCE AND TECHNOLOGY INFORMATION
142. Uçar, Esra and Özyi̇ği̇t, Yaşar and Turgut, Kenan, The Effect of Different Pollination Methods on Seed Yield and Germination Features in Stevia rebaudiana Bertoni, Türkiye Tarımsal Araştırmalar Dergisi, vol. 2, no. 2, pp. 114--117, September 2015. doi: 10.19159/tutad.44673. Abstract
     Pollination is a prerequisite system for reproductive of many plants and it is more important in self-compatible plants. Since, these plants need other flowers pollen for flower fertilization and seed production. In this study, the effects of different pollination methods (open/cross pollination, self-pollination with hand and control) on some features associated with seed production in Stevia rebaudiana were investigated. Stevia which belongs to the Asteraceae family and is used as sweetener has a self-incompatibility problem. In the experiment, ten plants which were planted in a row were covered with net in the field condition and five of them were selfed with hand pollination and remaining 5 plants were left as it is. Furthermore, five uncovered plants were left to cross-pollination by insects. At the end of the experiment, seed yield per plant, 1000 seed weight, black/filled seed rate, number of day to first germination and germination rate were determined in harvested seeds. According to the results, cross-pollination was more superior in respect to all features in Stevia. This status shows that insect population (especially bee) must be present in Stevia fields for successful seed production.
143. Uçar, Esra and Turgut, Kenan and Özyiğit, Yaşar and Özek, Temel and Özek, Gülmira, The Effect of Different Nitrogen Levels on Yield and Quality of Stevia (Stevia Rebaudiana Bert.), Journal of Plant Nutrition, vol. 41, no. 9, pp. 1130--1137, May 2018. doi: 10.1080/01904167.2018.1431673. Abstract
     In the present work, the efficiency of different nitrogen doses (0, 50, 100, 150, and 200 kg ha−1) on growth, yield, and quality of stevia (Stevia rebaudiana Bert.) was investigated in 2011–2013. The study was conducted in Antalya located in the Mediterranean Region of Turkey. Terra rossa type soil (LVx, FAO) characteristics of the experimental field were clay loam, with high amounts of lime (33,9\%) and slightly alkaline (pH 7.7). The experiment was carried out in randomized block design with four replications. All the results were summarized as mean of three years. The highest fresh and dry biomass yields (26.75 t ha−1 and 7.5 ha−1, respectively) were obtained from 150 kg ha−1 N dose and followed by 100 kg ha−1 N dose (26.29 t ha−1 and 7.24 ha−1, respectively). Whereas the highest fresh and dry leaf yields (13.27 t ha−1 and 3.82 t ha−1, respectively) were realized in 100 kg ha−1 N dose. Actually, all nitrogen doses gave higher biomass and leaf yields compared to the control. On the hand, major steviol glycosides (stevioside and rebaudioside A) in the leaf were not influenced by nitrogen levels. In conclusion, 100 kg ha−1 N dose was found to be suitable for cultivation of stevia under field conditions.
144. Umesha, K. and Smitha, G.R. and Sreeramu, B.S. and Waman, A.A., Organic Manures and Bio-Fertilizers Effectively Improve Yield and Quality of Stevia (Stevia Rebaudiana), Journal of Applied Horticulture, vol. 13, no. 02, pp. 157--162, December 2011. doi: 10.37855/jah.2011.v13i02.36. Abstract
     The influence of different organic manures, bio-fertilizers and green manures on growth, yield and glycoside content of stevia (Stevia rebaudiana) was studied over a period of three years (2004-2007). Various organic supplements viz., farm yard manure (15 and 25 t ha-1), vermicompost (1 and 2 t ha-1), neem cake (0.5 and 1 t ha-1) and bio-fertilizers viz., Azospirillum, phosphorus solubilizing bacteria and VAM (each @ 0 and 10 kg ha-1) were applied. The results of eleven harvests revealed that all the growth parameters viz., plant height, number of branches and plant spread were influenced by various organics and bio-fertilizers and showed variation from season to season (harvest to harvest) and plants responses did not followed a definite trend. Dry leaf yield during first (6.16 t ha-1) and second year (4.34 t ha-1) of cropping was maximum with the treatment receiving FYM (25 t ha-1) + vermicompost (2 t ha-1) + neem cake (1 t ha-1) + bio-fertilizers (10 kg ha-1) and differed significantly. However, in third year of cropping the treatments had no significant influence on the dry leaf yield. Both the glycosides i.e., stevioside (7.8 \%) and rebaudioside content (3.4 \%), and glycoside yield were also highest in the above said treatment.
145. Wu, Jing and Wang, Yiming and Lin, Xiangui, Purple Phototrophic Bacterium Enhances Stevioside Yield by Stevia Rebaudiana Bertoni via Foliar Spray and Rhizosphere Irrigation, PLOS ONE, vol. 8, no. 6, pp. e67644, June 2013. doi: 10.1371/journal.pone.0067644. Abstract
     This study was conducted to compare the effects of foliar spray and rhizosphere irrigation with purple phototrophic bacteria (PPB) on growth and stevioside (ST) yield of Stevia. rebaudiana. The S. rebaudiana plants were treated by foliar spray, rhizosphere irrigation, and spray plus irrigation with PPB for 10 days, respectively. All treatments enhanced growth of S. rebaudiana, and the foliar method was more efficient than irrigation. Spraying combined with irrigation increased the ST yield plant -1 by 69.2\% as compared to the control. The soil dehydrogenase activity, S. rebaudiana shoot biomass, chlorophyll content in new leaves, and soluble sugar in old leaves were affected significantly by S+I treatment, too. The PPB probably works in the rhizosphere by activating the metabolic activity of soil bacteria, and on leaves by excreting phytohormones or enhancing the activity of phyllosphere microorganisms.
146. Xu, Jiangbing and Feng, Youzhi and Wang, Yiming and Wang, Junhua and He, Xinhua and Lin, Xiangui, Soil Microbial Mechanisms of Stevia Rebaudiana (Bertoni) Residue Returning Increasing Crop Yield and Quality, Biology and Fertility of Soils, vol. 49, no. 7, pp. 839--846, October 2013. doi: 10.1007/s00374-013-0777-7. Abstract
     Due to the ever-increasing worldwide plantation of sweet leaf Stevia rebaudiana (Bertoni), how to efficiently and effectively utilize the huge amounts of leaf residues that contain abundant nutrients after sweetener extraction becomes an eminent issue. One option is to return these residues into soil, as organic manure in the fresh or composted form, in order to both sustain soil fertility and avoid potential environmental pollution. In a field experiment, we studied if the Stevia leaf residue returning affected both plant and soil microbial growths as well as the possible change of soil microbial community composition. In doing so, four treatments were employed: (1) no chemical fertilization and no Stevia residue returning (no-fertilization control); (2) chemical N, P, and K fertilization (NPK); (3) fresh Stevia residue plus NPK (FS + NPK); and (4) composted Stevia residue plus NPK (CS + NPK). Responses of plant and soil microbial communities to Stevia residue input after 1-year fertilizations were investigated by multiple approaches, including soil enzyme assay, real-time quantitative polymerase chain reaction, and PCR–denaturing gradient gel electrophoresis. Our results showed that compared to the sole NPK and no-fertilization control, returning Stevia residues to soil stimulated the enzyme activities of dehydrogenase, invertase, and urease, except neutral phosphomonoesterase; thereby, both the Stevia leaf biomass and sweet glycoside of rebaudioside A were increased. The soil microbial community abundance was increased by the returning of Stevia residues, and their composition was shifted, evidenced by an increase of relative abundance of some genotypic groups, such as Bacillales. Further molecular analysis of Bacillus confirmed that this guild composition was positively influenced by Stevia residue returning, especially for Bacillaceae. Our results demonstrated an effective use of Stevia residues as organic manure for promoting Stevia yield and quality through stimulating soil microbial growth and enzyme activities.
147. Yang, Jingtian and Liu, Xiangyang and Shi, Yan, Effect of Different Mixed Fertilizer on Yield, Quality and Economic Benefits in Stevia Rebaudiana Bertoni, Advance Journal of Food Science and Technology, vol. 5, no. 5, pp. 588--591, May 2013. doi: 10.19026/ajfst.5.3132. Abstract
     The effect of different mixed fertilizer on yield, quality and economic benefits in Stevia rebaudiana Bertoni had been studied in open field. The result showed that organic cultivation and the common had some remarkable difference in yield, quality, as well as the economic benefits. Leaf production of treatment that incorporating organic fertilizer with decomposed Stevia rebaudiana dregs lower than the one that incorporating organic fertilizer with inorganic fertilizer, yet higher than applying organic fertilizer only and inorganic fertilizer only; organic cultivation enable Stevia rebaudiana produced more Stevioside (STV) in leaf blade compared with common cultivation, especially in the content of Rebaudioside A (RA); and incorporating organic fertilizer with decomposed Stevia rebaudiana dregs led to a significantly higher economic benefit compared with others.
148. {Yong-ping}, Zhao and {Hai-ming}, L. I. N. and {Qing-xiang}, H. E. and {En-he}, Zhang and {Yu-jie}, W. E. I., Comparative Study on Photosynthetic Physiological Characteristics, Yield and Quality of Different Genotypes of Stevia Rebaudiana, Journal of Nuclear Agricultural Sciences, vol. 28, no. 5, pp. 935, May 2014. doi: 10.11869/j.issn.100-8551.2014.05.0935. Abstract
     In order to select the suitable Stevia rebaudiana for planting and hig...
149. Zaman, M. M. and Rahman, Md Arifur and Chowdhury, Tanzin and Chowdhury, M. a. H., Effects of Combined Application of Chemical Fertilizer and Vermicompost on Soil Fertility, Leaf Yield and Stevioside Content of Stevia, Journal of the Bangladesh Agricultural University, vol. 16, no. 1, pp. 73--81, April 2018. doi: 10.3329/jbau.v16i1.36484. Abstract
     Sustainable nutrient management with the combination of organic and chemical fertilizer amendment expects a key part in upgrading stevia yield without harming the environment and to build up the nutrient balance with increasing soil fertility. A pot experiment was conducted in the net house of the Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh to study the combined effect of vermicompost (VC) and chemical fertilizer (CF) on the growth, leaf biomass yield and stevioside content of stevia in acid soil. Six combinations of VC and CF were applied following completely randomized design (CRD) with three replications. Results showed that VC along with different rates of CF exerted significant influence on the growth, leaf biomass yield and stevioside content of stevia and postharvest soil fertility. The highest values for most of the parameters were found from the plant receiving VC @ 7.5 t ha­−1 along with 50\% CF. About 578\% higher leaf biomass yield was obtained from the treatment VC7.5+CF50 over control. Stevioside content was increased with the increasing levels of VC up to 7.5 t ha−1 along with 75\% of CF and also with the advancement of growth period from 30 to 60 days after planting. The highest amount of stevioside (11.05\%) was detected in the leaves of plant of the same treatment at harvest. Soil acidity was significantly decreased with the increased levels of VC and CF where as soil fertility in terms of organic matter and nutrient content was increased. Considering the overall performance, farmers may be advised to cultivate stevia in acid soil applying VC @ 7.5 t ha−1 along with 50\% chemical fertilizer to boost up stevia production under the agroclimatic condition of the study area in the context of BangladeshJ. Bangladesh Agril. Univ. 16(1): 73-81, April 2018
150. Zaman, M. M. and Chowdhury, M. a. H. and Chowdhury, Tanzin, Growth Parameters and Leaf Biomass Yield of Stevia (Stevia Rebaudiana, Bertoni) as Influenced by Different Soil Types of Bangladesh, Journal of the Bangladesh Agricultural University, vol. 13, no. 1, pp. 31--37, 2015. doi: 10.3329/jbau.v13i1.28708. Abstract
     Soils of different types affect crop production according to their capability as a nutrient supplier based on plant requirement. Soil provides physical support to plant as well as supplies necessary water and nutrient elements for plant growth and development. Suitable soil for stevia cultivation in Bangladesh is yet to be identified. A high concentrate sweetness producer plant, stevia (Stevia rebaudiana Bertoni) was grown in earthen pots in some soils of Bangladesh to choose the most suitable soil/s for the growth and leaf yield of stevia. Seven soil types namely acid, calcareous, non-calcareous, charland, saline, peat and acid sulphate were used as treatments. The soils were mostly light grey in colour and clay to clay loam in texture. Bulk density, particle density and field capacity ranged from 1.24-1.45, 2.20-2.58 and 27.03-30.19\%, respectively. pH, EC and organic matter content ranged from 3.90-8.00, 0.25-14.00 dS m-1 and 0.88-16.40\%, respectively. Total N, exchangeable K, available P and S contents ranged from 0.05-0.96\%, 0.17-0.70 cmol kg-1 soil, 3-12 and 11-735 ?g g-1 soil, respectively. Different soil types significantly influenced the growth and leaf yield of stevia. The highest values of plant height, branch and leaf number, leaf area, fresh and dry weight of leaves were obtained from the plant grown in non-calcareous soil which was identical with the plant those grown on acid soil while the lowest values of all the parameters were found from the plant grown in acid sulphate soil. Leaf biomass yield increase ranged from 16.18\% in peat soil and 90.11\% in non-calcareous soil over acid sulphate soil. The performance of the soils in terms of stevia leaf production was of the order non-calcareous\> acid\> calcareous\> charland\> saline(4.43 dS m-1)\> saline(6.08 dS m-1)\> saline(8.68 dS m-1)\> peat \>acid sulphate soils. The overall results suggest that farmers could be advised to grow stevia either in non-calcareous soil or acid soils of Bangladesh.J. Bangladesh Agril. Univ. 13(1): 31-37, June 2015
151. Integrated Effects of Poultry Manure and Chemical Fertilizer on the Growth, Leaf Yield and Stevioside Content of Stevia, Journal of the Bangladesh Agricultural University, 2015. doi: 10.22004/ag.econ.235278. Abstract
     Stevia is important for its leaves which are used as non calorie sweetener and also in many therapeutic applications including diabetes. The present investigation was carried out in the net house of the Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh to investigate the integrated effects of poultry manure (PM) and chemical fertilizer (CF) on the growth, leaf biomass yield and stevioside content of stevia grown in two contrasting soils (acid and non-calcareous) of Bangladesh. Six combinations of PM and CF viz. PM0+CF0, PM0+CF100, PM3+CF50, PM3+CF75, PM5+CF50, PM5+CF75 were used. The study revealed that PM along with different percentages of chemical fertilizers exerted significant influence on the growth, leaf yield and stevioside content of stevia. The highest values of all the parameters except stevioside were found from the plant receiving PM @ 3 t ha-1 along with 75\% CF. The leaf biomass yield was 1088\% and 867\% higher in acid soil and non-calcareous soil, respectively, over control. Stevioside content was increased with increasing the levels of PM up to 5 t ha-1 and also with the advancement of growth period from 30 to 60 days after planting. The highest amount of stevioside (10.45\%) was detected in the leaves of the plant that received PM @ 5 t ha-1 along with 75\% CF at 60 DAP in acid soil and it was 9.11\% in non-calcareous soil at the same period. The lowest values of all the parameters including stevioside content were obtained from the plant which received neither PM nor CF. Considering the overall performance, farmers may be advised to cultivate stevia in acid soil applying PM @ 3 t ha-1 along with 75\% chemical fertilizer to boost up the production of stevia under the agro-climatic condition of the study area in the context of Bangladesh
152. Çikman, Münevver and Koşar, İslim and Ozel, Abdulhabip, Determination of Yield and Some Agricultural Characters on Stevia (Stevia Rebaudiana Bertoni) under the Harran Plain Condition, Harran Tarım ve Gıda Bilimleri Dergisi, vol. 23, pp. 410--421, November 2019. Abstract
     This study was carried out in the 2nd year of the experiment, which was established in 2016 summer gowing period, at the GAP Agricultural Research Institute, Talat Demirören Research Station, to determine the yield and some agricultural characters on Stevia rebaduiana Bert. under the Harran Plain conditions. According to results of the trial the 1st harvest, average flowering days number was 127.32 day, plant height 68.90 cm, branches number 5.72 pieces plant-1, green herb weight 256.92 g plant-1, green leaf weight 161.52 g plant-1, dry leaf weight 53.13 g plant-1, dry leaf ratio 66.47\%, water dissolved dry matter ratio in leaf 2.93\% and in stem 2.26\%. In the second harvest, flowering days number was 30.83 day, plant height 31.14 cm, number of main branches 5.59 pieces plant-1, green herb weight 29.82 g plant-1, green leaf weight 21.70 g plant-1, dry leaf weight 6.71 g plant-1, dry leaf ratio 76.25\%, water dissolved dry matter ratio in leaf 1.86\% and in stem 1.57\%. As a result of the correlation, it was positive and significant relationship between the dry herb weight and plant height, number of leaves per plant, stems number, green herb weight, dry leaf ratio and dissolved matter in water ratio. When the results were evaluated in general; It could be said that two harvests can be taken annually the Stevia plant, but wilt disease can be seen before in the first harvest and the plants can be adversely affected by the high tepmparature in the second harvest period in the Harran Plain conditions.
153. Ascrizzi, Roberta and De Leo, Marinella and Pistelli, Laura and Giuliani, Claudia and Pieracci, Ylenia and Ruffoni, Barbara and Mascarello, Carlo and Fico, Gelsomina and Flamini, Guido and Pistelli, Luisa, Resilience of Stevia Rebaudiana (Bertoni) Bertoni in the Underwater Biospheres of Nemo’s Garden®: Adaptation to New Cultivation Systems, Molecules, vol. 27, no. 23, pp. 8602, January 2022. doi: 10.3390/molecules27238602. Abstract
     The Nemo’s Garden® project is an alternative production system for areas with scarce cultivable land but significant presence of water; thus, it is an interesting intervention to address the climate crisis. This work aimed to evaluate the micromorphological, biochemical, and phytochemical characteristics of Stevia rebaudiana (Bertoni) Bertoni grown underwater compared to the terrestrial specimens. The micromorphological analyses, performed on the leaves using light microscopy, fluorescence microscopy, and scanning electron microscopy, evidenced a general uniformity of the trichome morphotype and distribution pattern. The histochemical investigation indicated the simultaneous presence of terpenes and polyphenols in the trichome secreted material from the underwater samples and a prevailing polyphenolic content in the terrestrial specimens; this was also confirmed by biochemical analyses (26.6 mg GAE/g DW). The characterization of non-volatile components, performed using HPLC–MS, showed similar chemical profiles in all the samples, which were characterized by phenolic compounds and steviol glycosides. The volatile compounds, evaluated using HS-SPME coupled with GC–MS, showed sesquiterpene hydrocarbons as the main class in all the analyzed samples (80.1–93.9\%). However, the control plants were characterized by a higher content of monoterpene hydrocarbons (12.1\%). The underwater biosphere environment did not alter S. rebaudiana micro-morphological characters, although slight qualitative changes were evidenced for the compounds produced as a response to the growth conditions.
154. Saravi, Hadiseh Bahari and Gholami, Ahmad and Pirdashti, Hemmatollah and Firouzabadi, Mehdi Baradaran and Asghari, Hamidreza, The Response of Stevia (Stevia Rebaudiana Bertoni) Photosystem II Photochemistry to Fungi Symbiosis and Spermidine Application under Saline Water Irrigation, Russian Agricultural Sciences, vol. 47, no. 1, pp. 32--36, January 2021. doi: 10.3103/S106836742101016X. Abstract
     Since the medicinal plants mainly are cultivated in marginal areas, are exposed to environmental stresses such as salinity, more than other plants. Salt stress causes damage to photosynthetic process, carbohydrates assimilation and photosystem I and II. However, recently, the role of fungi coexistence and polyamines in plants tolerance to saline conditions are pronounced. Therefore, the present study was conducted to evaluate the effects of endophyte symbiosis and spraying of polyamine spermidine (Spd) on chlorophyll fluorescence parameters of stevia (Stevia rebaudiana Bertoni) medicinal plant under irrigation with saline water. Treatments included non-inoculation (Control) or co-inoculation of Piriformospora indica + Trichoderma virens (Pi + Trich), foliar application of Spd (0 and 0.75) and three salinity levels of Caspian sea water (0, 6 and 12 dS m–1). Seedlings of stevia were transplanted in field conditions and were sprayed with Spd solutions after 9 weeks of planting. Seven days later, the plants were irrigated with three saline treatments for two weeks. The results showed that the foliar application of Spd had a positive effect on Fm, Fv and Fv/Fm and negative effect on Y(NO). Irrigation of plants with saline water had an adverse effect on fluorescence parameters. However, fungi inoculation markedly increased Fm, Fv, Fv/Fm and Y(II) while decreased Fo, Y(NPQ) and Y(NO) in all levels of salt stress. Fungal inoculation and Spd application with 0.75 mM remarkably enhanced Fm. Generally, inoculation of endophytic fungi and Spd spraying improved the chlorophyll fluorescence parameters and adjusted adverse effects of salinity stress in stevia plants.
155. Zamani, Ameneh and Karimi, Mojtaba and {Abbasi-surki}, Ali and {Direkvand-moghadam}, Fatemeh, The Effect of Humic Acid Application on Stevia (Stevia Rebaudiana) Growth and Metabolites under Drought Stress, Iranian Journal of Plant Physiology, vol. 11, no. 3, pp. 3651--3658, April 2021. doi: 10.30495/ijpp.2021.682479. Abstract
     {$<$} p{$>$}The soil water limitation is a relevant abiotic stress that affects the plants life. In this respect, adoption an efficient strategy may improve the plant growth during this stress. The present study was conducted in order to find the likely useful effect of the humic acid (HA) on Stevia (Stevia rebaudiana) in a pot trial, especially under drought stress condition. Therefore, five levels of humic acid (0, 1, 1.5, 2 and 2.5 mg.kg-1 of soil) were applied in the soil containing Stevia seedling under normal (well-watered) and drought stress condition (resulted from 10-days irrigation intervals), based on a factorial experiment with three replications. Drought stress significantly reduced the Stevia leaf production and steviol glycosides (SVglys) content and compositions. Stevioside (Stev) and Rebaudioside A (Reb A) contents were significantly decreased by drought stress and all concentrations of HA. On the other hand, HA (in concentration more than 1.5 mg.kg-1 of soil) strongly increased the leaf production in Stevia and resulted in a significant increase of the SVglys yield (44\% in comparison with no HA). Results clearly demonstrated that although HA showed an inhibitory effect for SVglys content in Stevia leaf, it can increase the SVglys yield through a remarkable increase in leaf growth in Stevia, especially under drought stress condition.
156. Gerami, Mahyar and Majidian, Parastoo and Ghorbanpour, Akram and Alipour, Zeinab, Stevia Rebaudiana Bertoni Responses to Salt Stress and Chitosan Elicitor, Physiology and Molecular Biology of Plants, vol. 26, no. 5, pp. 965--974, May 2020. doi: 10.1007/s12298-020-00788-0. Abstract
     This study examined the effect of chitosan elicitor with four different concentrations (0, 0.2, 0.4 and 0.6~g/l) on physiological and biochemical properties of stevia under four levels of salinity stress (0, 50, 100, 150~mM level of NaCl). Salt stress caused reduction of chlorophyll a (Chl a), chlorophyll b (Chl b), total chlorophyll, carotenoid and total protein content. The increment of malondialdehyde (MDA) content was not significant in all NaCl levels, while the CAT and POX activities were increased as well as stevioside and rebaudioside A under salinity stress. On one side, chitosan treatments could compensate the reduction of physiological traits such as photosynthetic pigments and protein content. On the other side, chitosan caused multiple increases in malondialdehyde content, antioxidant enzymes activity (catalase and peroxidase), steviol glycosides (stevioside and rebaudioside A) under salt stress. We report for the first time, the potential of chitosan to enhance salinity-tolerant abilities in stevia through increment of the salt-adaptive factors and to diminish harmful damages caused by NaCl stress.
157. Aghighi Shahverdi, Mehdi and Omidi, Heshmat and Tabatabaei, Seyed Jalal, Stevia (Stevia Rebaudiana Bertoni) Responses to NaCl Stress: Growth, Photosynthetic Pigments, Diterpene Glycosides and Ion Content in Root and Shoot, Journal of the Saudi Society of Agricultural Sciences, vol. 18, no. 4, pp. 355--360, October 2019. doi: 10.1016/j.jssas.2017.12.001. Abstract
     The aims of the experiment were to determine NaCl threshold and evaluate the effect of NaCl stress on the growth and physiological traits of stevia (sugerleaf). For these aims, a greenhouse experiment was carried out with six NaCl concentration levels (NaCl 0, NaCl 30, NaCl 60, NaCl 90, NaCl 120 and NaCl 150\,mM). The plants were grown in pots and irrigated with Hoagland nutrient solution during 62\,days. NaCl threshold and EC50 (the NaCl level that 50\% of yield reduction) achieved 77.10 and 157.08\,mM, respectively. NaCl stress caused reduction of plant height, leaf fresh and dry weight, chlorophyll a (Chl a), chlorophyll b (Chl b), total chlorophyll (total Chl), K+ content in root and shoot organs. On the other hand, NaCl stress caused an increase of malondialdehyde content (MDA), Na+ content in root and shoot and Na+/K+ ratio in root and shoot. The low level of NaCl (30\,mM) indicated the highest of Chl a, carotenoids, total sugar, the percentage of Steviosides (Stev), Rebaudioside-A (Reb-A) and Stev+Reb-A. The finding of this study leads to the conclusion that, low level of NaCl concentration (30\,mM) caused increasing steviol glycosides and the result showed stevia as a moderate NaCl tolerant plant.
158. Angkapradipta, P. and {Tuti-Warsito} and Faturachim, P., N, P, K fertilizer requirement level of Stevia rebaudiana Bertoni M. on latosolic soil, Menara Perkebunan (Indonesia), 1986. url: https://agris.fao.org/search/en/records/6477517dbc45d9ecdbc09a28. Abstract
     An NPK factorial 5 x 2 x 2 pot experiment in a greenhouse using reddish brown latosol with a basal dressing of 200 gram cowdung manure per pot of 5,5 kg soil, was conducted during the period from February to August 1983. Each pot was supplied with one Stevia seedling. Yield response was assessed in terms of the above-ground fresh and dry matter weight of the cumulative yield of three harvests. Soil and plant analysis showed the following. Cowdung manure markedly improved the fertility level of the soil. Increasing rates of nitrogen did not affect the soil-N, but had a significant positive effect on plant-N content. Soil pH as well as K2O, CaO and MgO levels in the soil were depressed by increasing rates of nitrogen. The phosphorus and potassium fertilizer increased soil P2O5 and K2O contents, but did not affect P and K contents in the plant. Only nitrogen at the third level (N2) increased significantly the above-ground fresh and dry matter production, as well as fresh weight of roots. The results of this experiment suggest that the nitrogen requirement levels based on the quadratic regression of the fresh as well as the dry matter yields of the above-ground part are respectively 0,91 gram and 0,92 gram of Urea per plant for each application. These rates are restricted to the first year of harvest only. The phosphorus and potassium fertilizer requirement levels could not be determined from the results of this experiment.
159. Asghari, Robabeh, Effect of Different Plant Beds and Fertilizers on Stevia (Stevia Rebaudiana Bertoni) Production, Australian Journal of Crop Science, vol. 12, no. 1, pp. 51--55, January 2018. doi: 10.3316/informit.459388664406383. Abstract
     Stevia rebaudiana Bertoni is well-known for its high content of steviol glycoside, a diterpene compound (about 4–20\%) in dryleaf matter that is responsible for providing the non-caloric value sweet taste. Steviol glycosides are natural sugar substitutes for diabetics and other people on carbohydrate-controlled diets. Studies revealed that the glycosides yield, especially stevioside, greatly depends on the total biomass yield, which in turn depends on agricultural practices for cultivation of stevia. In this study, the effect of five various combinations of soil, cocopeat, perlite, and vermicompost plant beds mixed with four different fertilizers of tea compost, vermiwash, Hoagland and water, on four different physiological (leaf area, stem length, fresh weight and dry weight) and six different biochemical (chlorophyll content, carotenoid, protein, glucose, phenols and rebaudiosides) characteristics of plant were evaluated. To gain the highest content of biochemical compounds, especially all types of rebaudiosides, a combination of vermicompost, perlite and cocopeat with vermiwash or any other fertilizers can be useful
160. Das, Kuntal and Dang, Raman and Shivananda, T. N., Effect of N, P and K Fertilizers on Their Availability in Soil in Relation to the Stevia Plant (Stevia Rebaudiana Bert.), Archives of Agronomy and Soil Science, vol. 52, no. 6, pp. 679--685, December 2006. doi: 10.1080/03650340601033233. Abstract
     A greenhouse experiment was conducted at the Indian Institute of Horticultural Research (IIHR), Bangalore, to study the effect of combined applications of nitrogen (N), phosphorous (P) and potassium (K) fertilizers on their availability in soils in relation to their contents in the Stevia plant. The results show that the amount of available N, P and K in soil has been found to be increased initially up to 45 days and thereafter, the amount of the same content decreased with the progress of plant growth up to 60 days irrespective of treatments. However, the magnitudes of such increases in N, P and K contents both in soils and plants have also been enhanced with the simultaneous application of N, P and K (40:20:30) kg/ha over that of their corresponding individual applications.
161. Enchev, Stanimir and Mehmed, Ahmed and Kikindonov, Georgi, Effect of Mineral and Organic Fertilization on the Productivity of Stevia (Stevia Rebaudiana B.), Bulgarian Journal of Agricultural Science, vol. 24, no. Suppl. 2, pp. 100--103, 2018. url: http://agrojournal.org/24/02s-15.pdf. Abstract
     An experiment has been made in the fields of the Agricultural Institute – Shumen during 2013-2015 to study the effect of three organic and mineral products: Bioactive (100ml/da), Humustim (40 ml/da) and mineral nitrogen (20 kg/da), on the productive qualities of stevia (Stevia rebaudiana B.) For that aim I year seedlings were used. The parameters fresh and dry mass of a single plant, and fresh and dry mass yield from one da, were measured. It was established, that the highest fresh mass yield from a single plant is formed by the variant, treated with mineral Nitrogen (20 kg/da) – the average yield of fresh mass is with 90 g (75.8\%) higher than that of the untreated control. The tested organic and mineral products have positive influence on the dry mass yield index for the three years of testing.
162. Kenawy, Nareyman N., Chemical Evaluation of Some Stevia (Stevia Rebaudiana, Bertoni) Varieties of under Different Nitrogen Fertilization Levels, Annals of Agricultural Science, Moshtohor, vol. 56, no. 2, pp. 285--292, June 2018. doi: 10.21608/assjm.2018.48610. Abstract
     Two field experiments were carried out at agricultural research center, Giza, Egypt during 2015/2016 and 2016/2017 seasons to study the effect of nitrogen fertilizer levels (20, 30 and 40 kg N/ fed/cut.) on some steviavarieties (china1, Egy1, spanti and shou2). The highest nitrogen rate of 40 kg. N /fed /cut was significant in all studied yield andChemical characters and gave the highest values of stevioside\%. recorded (6.09 and 6.62\%), ,rebaudioside A\% ( 7.23 and 8.04\%), Stevioside kg /fed ( 238.9 and 286.1 kg ) and rebaudioside A kg /fed (287.2 and 350.5 kg) ), respectively as compared with the other two nitrogen treatments in both seasons. Stevia Varieties were significantly different in all studied yield characters. china 1 Varieties gave the highest values of stevioside\% (6.83 and 7.34 \%), rebaudioside A\% ( 8.44 and 9.26 \%), rebaudioside A kg /fed(300.8 and 363.2 kg ), respectively of all studied yield and chemical characters except for dry leaves yield kg/fed where Egy1varieties gave the highest values in the first and second seasons. .Concerning the effect of the interaction between nitrogen fertilizer levels and stevia varieties on yield and chemical characters, nitrogen fertilizer level of 40 kg N/ fed/cut applied to china1varieties gave the highest values in all studied yield and chemical composition except for dry leaves yield (kg/fed) where Egy1varieties and nitrogen fertilizer level of 40 kg N/ fed/cut gave the highest values in the first and second seasons.
163. Liu, Xiangyang and Ren, Guangxi and Shi, Yan, The Effect of Organic Manure and Chemical Fertilizer on Growth and Development of Stevia Rebaudiana Bertoni, Energy Procedia, vol. 5, pp. 1200--1204, January 2011. doi: 10.1016/j.egypro.2011.03.210. Abstract
     The effect of organic manure and chemical fert ilizer on growth and development of Stevia rebaudiana Bertoni had been studied in experimental plots in Qingdao Agricultural University. The results showed that organic manure cultivation promoted root activity in 40 days after transplanting compared with the chemical fertilizer cultivation, and the dry weight of the above-ground has exceeded chemical fert ilizer cultivation in 60 days after transplanting. The glycosides synthesis and accumulation main period was in the later growth stage, and organic manure improved the root activity and enhanced the photosynthesis rate in later growth stage, finally the biomass of stevia and the content of glycosides were also increased.
164. Liu, Xiangyang and Li, Guoqing and Shi, Yan, Effects of Collocation of Different Fertilizers on Photosynthesis Characteristics of Stevia Rebaudiana Bertoni, Research on Crops, vol. 15, no. 1, pp. 259, 2014. doi: 10.5958/j.2348-7542.15.1.037.
165. Inugraha, Inugraha and Maghfoer, M. D and Widaryanto, E., Response of Stevia (Stevia Rebaudiana Bertoni M) To Nitrogen and Potassium Fertilization, IOSR Journal of Agriculture and Veterinary Science, vol. 7, no. 10, pp. 47--55, 2014. doi: 10.9790/2380-071014755. Abstract
     Objective of this research was to obtain optimal dosages of nitrogen and potassium fertilization on growth, yield, and quality of stevia. The research was conducted using Randomized Block Design (RBD) by 3 replications, which was constructed in factorial that comprised of 2 factors. The first factor was dosage of the nitrogen with 4 (four) levels, such as: 100, 150, 200, and 250 kg N ha-1. The second factor was dosage of potassium with 3 (three) levels, such as: 75, 150, and 225 kg K2O ha-1. Result of the research showed that significant interaction between nitrogen and potassium fertilization has occurred on parameter of the plant growth, such as number of leaf, leaf area, leaf area index, and the total chlorophyll content. Separate application of nitrogen and potassium fertilization has significantly affected on the plant height, while the stomatal density was only affected by the application of nitrogen. Significant interaction between nitrogen and potassium application has occurred on plant biomass and the yield of leaf during the harvest period I, II, and total. During the period of total harvest, the fertilizing treatments of 200 kg N ha-1 and 225 kg K2O ha-1 have harvested fresh leaves and dry leaves for about 2,780 kg ha-1 and 636 kg ha-1, respectively. The increasing application of nitrogen from 100 to 250 kg N ha-1 has significantly increased the stevioside level of the stevia’s leaf linearly in accordance with the equation of Y = 0.000408 X + 0.439.
166. Vasilakoglou, Ioannis and Kalfountzos, Dimitrios and Gougoulias, Nikolaos and Reppas, Charalampos, Productivity of Two Stevia Varieties under Reduced Irrigation and Fertilization Inputs, Archives of Agronomy and Soil Science, vol. 62, no. 4, pp. 457--472, April 2016. doi: 10.1080/03650340.2015.1060554. Abstract
     A 3-year field study was conducted in central Greece to determine the productivity of two stevia [(Stevia rebaudiana (Bertoni) Bertoni] varieties (‘Morita’ and ‘Candy-stevia’) under normal and reduced irrigation (100\% and 75\% of the evapotranspiration) and fertilization [1:0.8:1.1 or 1:0.4:0.8 N:P:K ratio in the first year and only N fertilization (100\% or 74\% of the recommended rate) in the second and third years] inputs. Averaged across years, stevia cv. Morita achieved greater dry leaf yield (3.48 t ha−1) than the cv. Candy-stevia (2.85 t ha−1). Irrigation and fertilization inputs did not significantly affect stevia cv. Morita dry leaf and steviol glycosides (stevioside plus rebaudioside-A) yields; however, decreasing irrigation and fertilization caused slight reduction of cv. Candy-stevia yields. In cv. Morita leaves, the concentrations of stevioside and rebaudioside-A ranged from 5.97\% to 7.78\% and 3.73\% to 4.79\%, respectively, while the corresponding concentrations in cv. Candy-stevia leaves were 8.21–9.36\% and 3.89–6.33\%. Conclusively, both stevia varieties could achieve satisfactory dry leaf biomass and steviol glycosides yield, even when grown under reduced irrigation (at 75\% of evapotranspiration) and reduced N fertilization (74\% of the recommended rate). Thus, stevia could represent an alternative crop to tobacco in the Mediterranean conditions.
167. Yakimov, Dimitar and Nikolova, Elena, Effectiveness of Biofertilizers on the Productivity of Dry Mass of Stevia Rebaudiana B., February 2018. url: http://regions.uard.bg/index.php/jubilee/jisc/paper/view/135. Abstract
     In recent decades, the increased interest in natural sweeteners has prompted manufacturers to develop mechanized technologies for the production of dry mass for stevioside for the food and pharmaceutical industry. The yield of dried leaves obtained from one plant affects all the elements of the technology. The results of a number of studies have shown that leaf fertilization is an appropriate method for stimulating the biological potential of plants and for the widespread farming practice, it is particularly important to establish the effect of different bio-fertilizers in a specific soil climate. The purpose of this study is to determine the effectiveness of various bio fertilizers on the productivity of Stevia leaves because of constantly growing organic farming areas. The results of the study found that the influence of the used foliar fertilizers influences the biological activity of the plants, leading to an increase in Stevia's vegetative mass and is a prerequisite for higher yields. The highest values of the studied parameters are the organic liquid fertilizer Ecosyst-Arbanasi, followed by Gropaid NPA.
168. Zare Hoseini, Raziye and Mohammadi, Ebrahim and Kalatejari, Sepideh, Effect of Bio-Fertilizer on Growth, Development and Nutrient Content (Leaf and Soil) of Stevia Rebaudiana Bertoni, Journal of Crop Protection, vol. 4, no. 5, pp. 691--704, December 2015. url: http://jcp.modares.ac.ir/article-3-2883-en.html. Abstract
     The aim of this study was to evaluate the effect of bio-fertilizers on growth and development of plants in pots containing (V) vermicompost and (M) cow manure: (soil amendments) and (S) garden soil separately and in combination. In the first experiment, treatments included S (control), SM (soil + 15\%M + 0\%V), SMV10 (soil ...
169. Abdulameer, Dhulfiqar Aamer and Osman, Mohamad Bin and Sulaiman, Zulkefly and Yusop, Mohd Rafi and Abdullah, Shamsiah and Azizi, Parisa and Muttaleb, Qusay Abdulhamza, Assessment of {\emph{Stevia Rebaudiana}} Bertoni Genotypes via Morpho-Agronomic Traits under Two Light Conditions, American Journal of Plant Sciences, vol. 09, no. 07, pp. 1403, June 2018. doi: 10.4236/ajps.2018.97102. Abstract
     \emph{Stevia rebaudiana} Bertoni, a non caloric natural sweetner is currently the available substitute to sugar. It is a genus of about 150 species of herbs and shrubs, a compositae and native to Paraguay. However, stevia is a short day plant with almost a constant day length {$<$} 12 hours in Malaysia stevia generated to flower early. Therefore, the aim of the study was to investigate the effect of different day length on \emph{Stevia rebaudiana} genotypes in Malaysia. The experiment was undertaken during December 2016 to April 2017 in the Faculty of Design and Architecture, Universiti Putra Malaysia, Serdang, Selangor, Malaysia. Eight stevia genotypes namely (CHV1, Morita2, MS012, MS012 (4x), SA18, TPU, and hybrids IIUM-F1 and UiTM-H2) were evaluated for the agronomic traits under two conditions: sun light ({$<$}12 hours) and simulated light ({$>$}14 hours) using a factorial experiment. The agronomic performance of \emph{Stevia rebaudiana} was significantly in long day length ({$>$}14 hours) environment comparing with short day length ({$<$}12 hours) environment. Stevia plants under sun light start to flower after seven weeks, from the other hand stevia plants under simulated light did not flower. All stevia genotypes showed a high performance under long day length ({$>$}14 hours) environments.
170. Abdullateef, Raji and Osman, Mohamad, Effects of Visible Light Wavelengths on Seed Germinability in Stevia Rebaudiana Bertoni, International Journal of Biology, vol. 3, no. 4, pp. p83, September 2011. doi: 10.5539/ijb.v3n4p83. Abstract
     Stevia rebaudiana Bertoni is one of 154 members of the genus Stevia and it produces sweet steviol glycosides .It originated from Paraguay. The leaves were used as general sweetening agent. Seed germination in Stevia is generally very low and constituted major obstacle to large scale production of the crop. Different wavelengths from visible light were tested on germination of Stevia seeds. The two lights used were (i) white light - 400 to 700nm, and (ii) red light - 660nm. Parameters evaluated include (i) Mean time germination, (ii) mean daily germination, (iii) germination rate, (iv) daily germination speed and (v) germination value. Multivariate tests at probability level {$<$}.05 revealed that daily germination speed and number of germinated seeds were significantly higher at ({$<$} .001) and ({$<$} .014) respectively with the effect of red light on seed germination. Red light (660nm) had better influence on germination in Stevia seeds than white light (400-700nm) and control experiment.
171. Idrees, Muhammad and Sania, Bibi and Hafsa, Bibi and Kumari, Sana and Khan, Haji and Fazal, Hina and Ahmad, Ishfaq and Akbar, Fazal and Ahmad, Naveed and Ali, Sadeeq and Ahmad, Nisar, Spectral Lights Trigger Biomass Accumulation and Production of Antioxidant Secondary Metabolites in Adventitious Root Cultures of Stevia Rebaudiana (Bert.), Comptes Rendus Biologies, vol. 341, no. 6, pp. 334--342, July 2018. doi: 10.1016/j.crvi.2018.05.003. Abstract
     Stevia rebaudiana (S.~rebaudiana) is the most important therapeutic plant species and has been accepted as such worldwide. It has a tendency to accumulate steviol glycosides, which are 300 times sweeter than marketable sugar. Recently, diabetic patients commonly use this plant as a sugar substitute for sweet taste. In the present study, the effects of different spectral lights were investigated on biomass accumulation and production of secondary metabolites in adventitious root cultures of S.~rebaudiana. For callus development, leaf explants were excised from seed-derived plantlets and inoculated on a Murashige and Skoog (MS) medium containing the combination of 2,4-dichlorophenoxy acetic acid (2, 4-D, 2.0mg/l) and 6-benzyladenine (BA, 2.0mg/l), while 0.5mg/l naphthalene acetic acid (NAA) was used for adventitious root culture. Adventitious root cultures were exposed to different spectral lights (blue, green, violet, red and yellow) for a 30-day period. White light was used as control. The growth kinetics was studied for 30days with 3-day intervals. In this study, the violet light showed the maximum accumulation of fresh biomass (2.495g/flask) as compared to control (1.63g/flask), while red light showed growth inhibition (1.025g/flask) as compared to control. The blue light enhanced the highest accumulation of phenolic content (TPC; 6.56mg GAE/g DW), total phenolic production (TPP; 101mg/flask) as compared to control (5.44mg GAE/g DW; 82.2mg GAE/g DW), and exhibited a strong correlation with dry biomass. Blue light also improved the accumulation of total flavonoid content (TFC; 4.33mg RE/g DW) and total flavonoid production (TFP; 65mg/flask) as compared to control. The violet light showed the highest DPPH inhibition (79.72\%), while the lowest antioxidant activity was observed for control roots (73.81\%). Hence, we concluded that the application of spectral lights is an auspicious strategy for the enhancement of the required antioxidant secondary metabolites in adventitious root cultures of S.~rebaudiana and of other medicinal plants.
172. Munz, Sebastian and Präger, Achim and Merkt, Nikolaus and Claupein, Wilhelm and {Graeff-Hönninger}, Simone, Leaf Area Index, Light Interception, Growth and Steviol Glycoside Formation of Stevia Rebaudiana Bertoni under Field Conditions in Southwestern Germany, Industrial Crops and Products, vol. 111, pp. 520--528, January 2018. doi: 10.1016/j.indcrop.2017.11.021. Abstract
     For the optimization of agronomic practices in stevia (Stevia rebaudiana Bertoni) cultivation in Europe, more knowledge is required concerning the influence of temperate environmental conditions on plant growth and yield of steviol glycosides (SVgly). The objectives of this study were to evaluate growth and SVgly yield of two stevia genotypes with different plant architecture under field conditions in southwestern Germany and to investigate the influence of the different plant architecture on light interception. Two stevia genotypes were grown at two planting dates in 2014 and 2015. Measurements comprised leaf area index (LAI), biomass growth, SVgly yield, and continuous measurements of light interception over a 33-day period. This study demonstrated that high yields of dry leaves (6000–7800kgha−1), total SVglys (720–1023kgha−1), and rebaudioside A (RA, 220–376kgha−1) can be achieved under temperate climate conditions. Under higher radiation and lower precipitation in 2015, LAI was considerably lower, however, final leaf and SVgly yield were not decreased and concentrations of RA were higher. Regressions of LAI on light interception showed large differences with a 95\% light interception at an leaf area index of 5.22 compared with 2.83 between genotypes. This study highlights the importance of future studies regarding physiological responses of stevia under dynamic environmental conditions also taking into account genotypic architectural traits in relation to light interception.
173. Simlat, Magdalena and Ślęzak, Patrycja and Moś, Maria and Warchoł, Marzena and Skrzypek, Edyta and Ptak, Agata, The Effect of Light Quality on Seed Germination, Seedling Growth and Selected Biochemical Properties of Stevia Rebaudiana Bertoni, Scientia Horticulturae, vol. 211, pp. 295--304, November 2016. doi: 10.1016/j.scienta.2016.09.009. Abstract
     Poor germination of Stevia rebaudiana Bertoni seeds is a phenomenon with unknown reason and the research concerning the improving of germination are still in progress. We investigated the influence of light-emitting diodes (LEDs) spectra on Stevia seed germination as well as seedling growth and selected morphological and biochemical parameters. Blue LED light increased seed germination and affected the development of the largest number of leaves and roots in 4-week-old Stevia plantlets. It has also the most favourable effect on the number and opening of stomata. Red LED light however, significantly increased the length of stems and roots, although there was not correlation with the fresh weight (FW). The highest FW of Stevia plantlets achieves under combined red and white LED light at temperature of 20°C as well as under white fluorescent light at temperature of 25°C. Blue LED light also positively affected the carotenoids concentration, whilst the highest concentration of chlorophyll a and b was found, in plantlets grown under white fluorescent light. The less favourable effect on the synthesis of all the examined pigments was exerted by red LED light. The largest amounts of phenolics and soluble sugars accumulated plantlets growing in the darkness and irradiated blue LED light. In addition, all LEDs affected the activity of antioxidant enzymes. The blue LED light increased the activity of catalase (CAT) and peroxidase (POD), especially at 25°C. Red LED light significantly increased activity of superoxide dismutase (SOD) whilst for the activity of CAT and POD opposite effect was observed. The combined red with white LED light was the most favourable for the activity of CAT at 25°C. We conclude that the seed germination and the quality of Stevia plantlets could be improved by controlling light quality.
174. Yoneda, Yuki and Shimizu, Hiroshi and Nakashima, Hiroshi and Miyasaka, Juro and Ohdoi, Katsuaki, Effects of Light Intensity and Photoperiod on Improving Steviol Glycosides Content in Stevia Rebaudiana (Bertoni) Bertoni While Conserving Light Energy Consumption, Journal of Applied Research on Medicinal and Aromatic Plants, vol. 7, pp. 64--73, December 2017. doi: 10.1016/j.jarmap.2017.06.001. Abstract
     Stevia rebaudiana (Bertoni) Bertoni accumulates steviol glycosides (SGs) which are natural sweeteners. Leaf extracts have been widely used as a food additive because the strong sweetness intensity of SGs that is 300 times sweeter than sucrose. S. rebaudiana is a short-day (SD) perennial plant, and some studies claim that long-day (LD) treatment affects SGs accumulation. However, the optimal and detailed light regime required to increase total SGs content remains controversial. We analyzed the effect of various light intensities and day lengths to determine optimal light treatment for SGs accumulation with minimal energy consumption in growth chambers. Night-interruption (NI) treatments in conjunction with 8h photoperiod increased leaf biomass to amounts observed under LD conditions, and resulted in higher SGs content than that observed under 12h photoperiod while minimizing energy consumption. In addition, end-of-day far-red (EOD-FR) treatment for 15min at 50μmolm−2s−1 was associated with transcription upregulation of the SGs-related gene UGT85C2, higher SGs content, and similar leaf biomass compared to that observed under 16h photoperiod. These light treatments offer great potential for energy-efficient increases in S. rebaudiana total SGs content when plants are grown in a greenhouse or in the field with supplemental lights.
175. Yoneda, Yuki and Nakashima, Hiroshi and Miyasaka, Juro and Ohdoi, Katsuaki and Shimizu, Hiroshi, Impact of Blue, Red, and Far-Red Light Treatments on Gene Expression and Steviol Glycoside Accumulation in Stevia Rebaudiana, Phytochemistry, vol. 137, pp. 57--65, May 2017. doi: 10.1016/j.phytochem.2017.02.002. Abstract
     Stevia rebaudiana (Bertoni) Bertoni is a plant that biosynthesizes a group of natural sweeteners that are up to approximately 400 times sweeter than sucrose. The sweetening components of S.~rebaudiana are steviol glycosides (SGs) that partially share their biosynthesis pathway with gibberellins (GAs). However, the molecular mechanisms through which SGs levels can be improved have not been studied. Therefore, transcription levels of several SG biosynthesis-related genes were analyzed under several light treatments involved in GA biosynthesis. We detected higher transcription of UGT85C2, which is one of the UDP-glycosyltransferases (UGTs) involved in catalyzing the sugar-transfer reaction, under red/far-red (R/FR) 1.22 light-emitting diodes (LEDs) and blue LEDs treatment. In this study, it was demonstrated that transcription levels of SG-related genes and the SGs content are affected by light treatments known to affect the GA contents. It is expected that this approach could serve as a practical way to increase SG contents using specific light treatments.
176. Debnath, M. and Ashwath, N. and Midmore, D. J., Physiological and Morphological Responses to Abiotic Stresses in Two Cultivars of Stevia Rebaudiana (Bert.) Bertoni, South African Journal of Botany, vol. 123, pp. 124--132, July 2019. doi: 10.1016/j.sajb.2019.01.025. Abstract
     Stevia rebaudiana (Bert.) Bertoni is cultivated for its sweet leaves as they contain steviol glycoside sweeteners such as stevioside and rebaudioside A. Two cultivars of S. rebaudiana, Shoutian-2 and Fengtian, were evaluated in a greenhouse for their tolerance to abiotic stresses. The seedlings were exposed to salinity, drought or waterlogging stresses for 4\,weeks. The cultivars differed significantly in their biomass accumulation, tissue ion concentrations and steviol glycoside accumulation. The salt tolerant cv. Fengtian contained higher concentrations of K+ which led to higher K+/Na+ ratio in the leaves, as compared to the less salt tolerant cv. Shoutian-2. Reduced biomass accumulation in cv. Shoutian-2 coincided with increased Na+ and Cl˗ concentrations in the leaves. The waterlogging stress reduced growth of both cultivars, but the salinity stress increased rebaudioside A concentration in the tolerant cv. Fengtian, and the drought stress increased stevioside concentration in the cv. Shoutian-2. This study concludes that the two cultivars of S. rebaudiana differ in their tolerances to salinity and drought stresses.
177. Le Bihan, Zoé and Cosson, Patrick and Rolin, Dominique and {Schurdi-Levraud}, Valérie, Phenological Growth Stages of Stevia (Stevia Rebaudiana Bertoni) According to the Biologische Bundesanstalt Bundessortenamt and Chemical Industry (BBCH) Scale, Annals of Applied Biology, vol. 177, no. 3, pp. 404--416, 2020. doi: 10.1111/aab.12626. Abstract
     Stevia (Stevia rebaudiana Bertoni) is a perennial crop belonging to the Asteraceae family. Its main agronomic and industrial interest is the accumulation in its leaves of steviol glycosides (SG), natural acaloric sweeteners which are 300 times sweeter than sucrose. In order to expand phenotyping knowledge on this emerging crop, researchers and breeders need a universal scale to describe the development of this plant. The objective of this study was to describe the phenological growth stages of stevia through the use of the Biologische Bundesanstalt Bundessortenamt and Chemical Industry (BBCH) scale to provide a standard scale for stevia grown under temperate conditions of production and climate. The observation of phenological stages was performed on genetic resources and validated on stevia progenies grown in field conditions. The 10 phenological stages, namely germination, bud development, foliar development, side shoots appearance, stems elongation, development of harvestable part of the crop, inflorescence emergence, flowering, development of fruit, seeds ripening and senescence, were used to describe the stevia, supplemented with pictures. The chronology and duration of each stage were also observed and described according to the accumulation of degree days during the growing season. This study presents the first BBCH scale established for S. rebaudiana cultivated in temperate conditions and a chronology of phenological stages based on the accumulation of thermal time, through growing degree day calculation (°C/day). This work provides a tool that can be widely used by farmers, breeders and researchers leading to better agronomic management and scientific communication.
178. Jalilvand Shirkhanitabar, Hassan and Tavakoli, Afshin and Moradi, Foad and Shekari, Farid, Effect of Salicylic Acid Foliar Application on the Morphological and Biochemical Traits of Stevia (Stevia Rebaudiana), Journal of Plant Process and Function, vol. 9, no. 39, pp. 245--256, December 2020. url: http://jispp.iut.ac.ir/article-1-1432-en.html. Abstract
     A greenhouse study was conducted to evaluate of salicylic acid foliar effect on morphological and biochemical characters of Stevia (Stevia rebaudiana) based on a Completely Randomized Design (CRD) experiment with three replications in Qazvin, Iran in 2016. The treatments of this research were defined as salicylic acid foliar levels as 0 (control), 100, ...
179. Mamatkulovich, Begmatov Abdusamat and Sattarovich, Sattarov Abdumurod, Bioecological Properties Of Stevia Rebaudiana Bertoni In Introduction Conditions, The American Journal of Agriculture and Biomedical Engineering, vol. 2, no. 10, pp. 63--68, October 2020. doi: 10.37547/tajabe/Volume02Issue10-11. Abstract
     In the soil and climatic conditions of the Surkhandarya region, the biological characteristics of the tropical plant S. rebaudiana at the stages of ontogenesis have been studied for the first time. The regularities of growth and development, the timing of the onset of the phases of budding, flowering, fruiting during the propagation of plants by seed have been established.
180. Abdullateef, Raji Akintunde and Osman, Mohamad, Influence of Genetic Variation on Morphological Diversity in Accessions of Stevia Rebaudiana Bertoni, International Journal of Biology, vol. 3, no. 3, pp. p66, June 2011. doi: 10.5539/ijb.v3n3p66. Abstract
     Stevia rebaudiana, a non caloric natural sweetener is currently the available substitute to sugar. It is a genus of about 150 species of herbs and shrubs, a Compositae and a native to Paraguay. The aim of this study was to evaluate collected accessions of stevia and characterize their genetic divergence. In 2010, 10 stevia accessions were collected across different locations in Malaysia. At maturity they were evaluated using morphological parameters and collected data were subjected to‘t’ test analysis at p{$<$}.05 as follows-(i) Plant heights: MS012 \& SBK were significant at p{$<$}.001 and p{$<$}.002 respectively. (ii) Number of branches: BGI \& SBK were significant at p{$<$}.001 and p{$<$}.008 respectively.(iii) Number of corymbs: AZI was significant at p{$<$}.000, while BGI was significant at p{$<$}.033. (iv) Number of leaves: MS012 \& MS007 were respectively significant at p{$<$}.000 and p{$<$}.008. (v) Plant leaf size: AZI was significant at p{$<$}.003, MS007 at p{$<$}.005, and MS012 at p{$<$}.019 and (vi) stem girth: MS012 \& MRG were also significantly different at p{$<$}.000 and p{$<$}.001 respectively. MSO12, MS007 \& SBK had loads of promising genetic traits in studied accessions.
181. {H. Tavakoli Hasanaklou} and {A. Ebadi Khazineh Ghadim} and {F. Moradi} and {H. Hadavand Mirzaei} and {N. Tavakoli Hasanaklou}, Morphological and Physiological Characteristics of Stevia Rebaudiana Cultivated under Different Nitrogen Supplements and Growth Regulators, Russian journal of plant physiology, vol. 69, no. 3, pp. 49--49, 2022. doi: 10.1134/S1021443722030141. Abstract
     Steviol glycosides (SGs) are the important constituents of stevia. SGs biosynthesis is dependent on various nutrients. This study aimed to investigate the effects of nitrogen sources ([Formula: see text], [Formula: see text], and NH₄NO₃ each 150\% in modified Hoagland solution) and the plant growth regulators including 200 µM cytokinin (i.e., BAP), 200 µM auxin (i.e., NAA), and their combination on leaf yield, branching, and SGs yield through a hydroponic experiment. The data revealed that the application of NH₄NO₃ + BAP increased the outgrowth of buds and branching due to a decrease in endogenous auxin and abscisic acid concentrations. Results also showed that there were significant negative correlations between developed axillary buds and branching with endogenous auxin and abscisic acid concentrations. Compared to the control, growth parameters including stem dry weight (567\%) and total dry weight (358\%) in the first year and leaf dry weight (160\%) and height (483\%) in the second year significantly increased when the combination of NH₄NO₃ and BAP was used. The highest stevioside concentration was observed at using NH₄NO₃ and BAP + NAA in both 2018 and 2019. Besides, the highest rebaudioside-A concentration was detected as NO₃ and NAA were applied during the second year. However, the rebaudioside-B and steviolbioside concentrations were declined when plants were subjected to both nitrogen sources and plant growth regulators. Conclusively, the data acquired herein provided valuable clues as to how to successfully achieve the high productivity of stevia plant and biosynthesis of SGs under greenhouse conditions.
182. Kassahun, Beemnet and Zigene, Zewdinesh and Kebede, Wossen and Gebremeskel, Haileslassie and Mengesha, Beement and Damtew, Zewdinesh, Performance of Stevia (Stevia Rebaudiana Bertoni) For Morphological And Economic Traits Under Different Ecologies of Ethiopia, Journal of Agriculture and Development (JAD), vol. 2, pp. 54--67, January 2012. Abstract
     Stevia [Stevia rebaudiana Bertoni) is a perennial, calorie free natural sweet herb that belongs to the family Asteraceae. Its fresh leaves and leaf extracts are 15-30 and 250-330 times sweeter than common sugar, respectively. Despite its amazing characteristics, the plant has not been evaluated for its performance in morphological and economic traits in different ecologies of Ethiopia. For assessing the adaptability of the plant in different ecologies, data on morphological and chemical traits were collected from four locations for two years and summarized on mean basis. The performance of Stevia varied across the testing locations for all the studied parameters. In the first year, the highest fresh leaf yield of 2332 kg/ha and dry leaf yield 600 kg/ha was recorded at Chencha, and the respective lowest values of 992 and 225 kg were recorded at Awada. In the second year, the respective highest value of 3034 kg and lowest 1891 kg fresh leaf yield/ha was recorded at Wondo Genet and Debre Zeit. Whereas, the highest dry leaf yield of 769Kg/ha was at Awada and lowest yield of 541 kgha at Chencha. The respective percent increase values of 4.5, 14.7 and 45.2\% were observed in second year compared to the first year for plant height, fresh leaf yield/ha and dry leaf yield/ha. In the second year, number of branches/plant, fresh leaf yield/plant and dry leaf yield/plant had decreased by 46.74, 99.94 and 34.38\%, respectively. The stevioside content varied from 9.07-10.35\%, which is within the ranges of world reports. Therefore, Stevia can be cultivated for its intense sweet leaves and stevioside in selected areas of the country.
183. Maurya, Sanjeev Kumar and Garg, Sanjay Kumar, Effects of Macronutrients (N, P and K) on the Morphological and Biochemical Parameters of Stevia Rebaudiana (Bertani), Biotech Today : An International Journal of Biological Sciences, vol. 9, no. 1, pp. 49, 2019. doi: 10.5958/2322-0996.2019.00006.1.
184. Othman, Halimaton Saadiah and Osman, Mohamad and Zainuddin, Zarina, Genetic Variabilities of Stevia Rebaudiana Bertoni Cultivated in Malaysia as Revealed by Morphological, Chemical and Molecular Characterisations, AGRIVITA, Journal of Agricultural Science, vol. 40, no. 2, pp. 267--283, April 2018. doi: 10.17503/agrivita.v40i2.1365. Abstract
     Stevia rebaudiana Bertoni originally from Paraguay belongs in Asteraceae family. It is an alternative source of non-caloric sweetener due to the sweet steviol glycosides contained in the leaves. As an introduced species in Malaysia, it is important to elucidate the genetic variabilities and relatedness among stevia accessions in order to broaden the genetic basis for future stevia breeding. This study described morphological and chemical variations and investigates genetic relationships among stevia accessions derived from across Malaysia and Paraguay using inter simple sequence repeats (ISSR) markers. HPLC (high-performance liquid chromatography) analysis also revealed high variability with stevioside content between 4.54 \% (Taman Pertanian) to 20.36 \% (Bangi) and rebaudioside A content varied between 0.3 \% (Nilai) to 2.04 \% (MNQ). From 32 ISSR markers, a total of 332 bands were scored, of which 264 (78 \%) were polymorphic. The dendrogram from UPGMA (Unweighted Pair Group Method with Arithmetic Mean) cluster analysis separated 17 stevia accessions into 3 main groups. Rawang and Nilai were found to be closely related. The wide genetic variabilities among stevia accessions are a promising indicator towards the development of new stevia varieties. This valuable information will be able to assist parental selection in future stevia breeding programmes.
185. Shaverdi, M., Morpho-Physiological Response of Stevia (Stevia Rebaudiana Bertoni) to Salinity Under Hydroponic Culture Condition (A Case Study in Iran), Applied Ecology and Environmental Research, vol. 16, no. 1, pp. 17--28, 2018. doi: 10.15666/AEER/1601_017028. Abstract
     Salinity stress caused reduces root characteristics and changes in physiological traits (protein content, activity of CAT, POD, PPO and total antioxidant activity DPPH), and at the lowest salinity level (30 mM), the highest amount SVglys was obtained. Stevia (Stevia rebaudiana Bertoni) is a relatively unknown crop in Iran and many countries of world, with great potential as a natural sweeteners source. Stevia has a high content of sweeteners, which are up to 150 times sweeter than sugar, but virtually with no calories. An experiment was carried out to investigate the effect of salinity stress on root characteristics and physiological traits of stevia using six different concentrations of NaCl (0, 30, 60, 90, 120, and 150 mM) in Hoagland solution with four replications in open shading structures at Medicinal Plant Research Center, Shahed University of Tehran, Iran. The results showed that root characteristics (such as root fresh weight (RFW), root dry weight (RDW), root volume (RV), root length (RL), root area (RA), root diameter, root mass density (RMD), and dry root mass density (DRMD)) reduced with the intensification of NaCl. The effect of NaCl was significant on the protein content, activity of catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO), and DPPH. The increasing of NaCl caused significantly enhancement of protein content, CAT activity, and total antioxidant activity. The POD activity showed a significant decrease by the increasing of sodium chloride rate. The PPO and POD activities by the increasing sodium chloride rate showed a significant decrease. Steviol glycosides (SVglys) compositions: stevioside (Stev), rebaudioside A (Reb A), rebaudioside B (Reb B), rebaudioside C (Reb C) and dulcoside A (Dulc A) and SVglys content showed changes under the influence of salinity. In 30 mM NaCl treatment was obtained the highest value of total SVglys yield and SVglys content. The findings from this study lead to the conclusion that, salinity stress caused reduces root characteristics and changes in physiological traits (protein content, activity of CAT, POD, PPO and total antioxidant activity DPPH). On the other hand, at the lowest salinity level (30 mM), the highest amount SVglys was obtained. It seems that the high level of SVglys at lower salinity levels is one of the reasons for salinity tolerance in Stevia, which requires further investigation.
186. Soejarto, Djaja Djendoel, Botany of Stevia and Stevia Rebaudiana, pp. 22, November 2001. doi: 10.1201/9780203165942-10. Abstract
     In view of the fact that only a portion (about 50\%) of the members of the genus Stevia has been surveyed for the occurrence of the sweet-tasting compounds (Soejarto et al. 1982; 1983; Kinghorn et al. 1984), a review of the entire genus, in the context of its economic importance, will be useful in setting the stage for other discussions on chemistry, biology and economics. Thus, this chapter begins with an overview on the taxonomy of Stevia and species relationships within the genus, with the aim of providing a better perspective in the future search for sweet compounds in other members of the genus that have not been studied. Following a review of the genus, the discussion will shift into the subject plant, S. rebaudiana, for the remainder of the chapter.
187. {Wölwer-Rieck}, Ursula, The Leaves of Stevia Rebaudiana (Bertoni), Their Constituents and the Analyses Thereof: A Review, Journal of Agricultural and Food Chemistry, vol. 60, no. 4, pp. 886--895, February 2012. doi: 10.1021/jf2044907. Abstract
     The plant Stevia rebaudiana is well-known due to the sweet-tasting ent-kaurene diterpenoid glycosides. Stevioside and rebaudioside A are the most abundant and best analyzed, but more than 30 additional steviol glycosides have been described in the scientific literature to date. Most of them were detected in the last two years. This paper reviews these new compounds and provides an overview about novel trends in their determination, separation, analysis, detection, and quantification. The detection and analysis of further constituents such as nonglycosidic diterpenes, flavonoids, chlorogenic acids, vitamins, nutrients, and miscellaneous minor compounds in the leaves of Stevia rebaudiana are reviewed as well. A critical review of the antioxidant capacity of Stevia leaves and its analysis is also included. These different aspects are discussed in consideration of the scientific literature of the last 10 years.
188. Pedroza Carneiro, José, Stevia Rebaudiana (Bert.) Bertoni: Stages of Plant Development, Canadian Journal of Plant Science, vol. 87, pp. 861--865, October 2007. doi: 10.4141/P06-040. Abstract
     Vegetative and reproductive codes were developed to describe seeds under germination, normal seedlings, seedling growth, plant growth and branching, plant regrowth, flower buds, crop flowering (anthesis), developing seeds, seed dispersion, and senescent plants as V 0 , V 1.i , V 2.i , V 3.i.k , V 4.i.k , R 1.i , R 2.i , R 3.i , R 4.i and R 5.i , respectively. The numerical code attached to both capital letters indicates the stage, and the lower case letters i or k indicate a number or a percentage. Key words: Natural sweetener, plant regrowth, anthesis, seed, seedling, transplant
189. Carneiro, José Walter Pedroza, The Components of the Seed Purity Test Applied to Stevia Rebaudiana (Bert) Bertoni, pp. 8, November 2014. url: https://doi.org/10.13140/RG.2.1.4703.4405.
190. Hossa, Keila Regina and Carneiro, José Walter Pedroza and Guedes, Terezinha Aparecida and Braccini, Alessandro Lucca, Stevia Rebaudiana (Bert) Bertoni: Influence of Osmotic Stress and Seed Priming on Seed Germination under Laboratory Conditions, Acta Scientiarum. Agronomy, vol. 39, pp. 379--384, 2017-Jul-Sep. url: http://www.scielo.br/j/asagr/a/cczqCHXcb5J9XCtBzZXLSzS/?lang=en&format=html. Abstract
     ABSTRACT. The foremost factor necessary for plant growers cultivating large acreages of Stevia rebaudiana (Bert) Bertoni is the production of qualitative bedding plants. The objective of this study was to evaluate the influence of osmotic-priming on the uniformity of seed germination. First, we evaluated the percentage of normal seedlings from two seed samples harvested in 2011 and 2012. The seeds harvested in 2012 produced 71.4\% normal seedlings and thus they were used in the next experiments. The seeds were subjected to osmotic stress using five concentrations of polyethylene glycol (PEG-6000) at -0.2, -0.4, -0.6, -0.8, and -1.0 MPa in contrast with distilled water. Based on these first results, only -0.8 and -1.0 MPa were evaluated in the third experiment. The seeds were immersed in both concentrations of polyethylene glycol (PEG-6000) for imbibing at 20ºC for four, five, six, and seven days. Thereafter, we evaluated the time to the first normal seedling (Ti), time to the last normal seedling (Tf), percentage normal seedlings at the initial time (Pi) and percentage of normal seedlings at the end of every treatment (Pf). Osmotic priming increased the percentage of normal seedlings of the Stevia rebaudiana and reduced the time to the first and last germination events.
191. Raina, R. and Bh, Shes Kanta and {ari} and Ch, Romesh and Sharma, Yashpal, Strategies to Improve Poor Seed Germination in Stevia Rebaudiana, a Low Calorie Sweetener, Journal of Medicinal Plants Research, vol. 7, no. 24, pp. 1793--1799, June 2013. doi: 10.5897/JMPR12.226. Abstract
     Expanding cultivation of exotic \‘stevia\’ in mid- and low-hill areas of Himachal Pradesh, India, is difficult because of the problem of low seed fertility. The objectives of the present study were to devise strategies to produce fertile seed. Two distinct compatible morphotypes were isolated, which when used in pollination produced fertile seeds, whereas self-pollination always resulted in sterile seed set, indicating sporophytic self-incompatibility in the species. To obtain fertile seeds, a mixed population of compatible genotypes should be raised. Although sporophytic chromosome numbers ranging from 22 to 70 are reported in literature, both the morphotypes investigated had only 22 chromosomes but differed on the basis of leaf shape, shoot collar diameter, plant type (compact or loose) and stevioside/rebaudiosideA content. Key words:Stevia rebaudiana, chromosome number, pollination, stevioside, rebaudioside A.
192. Martini, Andrea and Tavarini, Silva and Macchia, Mario and Benelli, Giovanni and Canale, Angelo and Angelini, Luciana Gabriella, Floral Phenology, Insect Pollinators and Seed Quality of 36 Genotypes of Stevia Rebaudiana Bert. Cultivated in Italy, pp. 13--26, 2015. url: https://arpi.unipi.it/handle/11568/721465. Abstract
     The complex reproductive mechanisms and the poor seed germination represent serious obstacles towards large scale establishment of Stevia rebaudiana Bert. The main goal of this study was to evaluate differences in the reproductive development of 36 F1 open-pollinated genotypes during flowering formation, pollination and seed production in order to identify the best genotypes, environmental condition and plant-pollinator interactions, for seed production and quality. Germination characteristics of seeds obtained from different genotypes grown under greenhouse without pollinators, were analyzed. Reproductive phenology, from the beginning of flowering to seed maturity, have been studied and the numbers of corymbs quantified for every genotype. Pollinators’ diversity and abundance have been quantified over the whole flowering period. In Central Italy the flowering stage spans from beginning of September to the end of October, whereas seed formation and maturity lasts until the end of November. Flowering and seed formation overlap each other. The rainy conditions during flowering and seed formation hampered pollinators’ activity and the seed filling. All F1 genotypes showed a large variability in terms of flowering time, length of flowering and number of corymbs per plant. All genotypes were visited by insects during anthesis. Main pollinators were Hymenoptera and Diptera. Honeybees and hoverflies represented the most abundant species, followed by sweatbees and blowflies. Seed germination rate and mean energy time differed among the genotypes. Further differences were found in the seed quality as consequence of pollinator abundance and spectrum. Overall, our findings suggest that the genotype choice, cross-pollination, and environmental conditions during the reproductive stage, together with support of pollinators are important parameters for achieving high seed yield and quality in S. rebaudiana.
193. Gupta, Ena and Purwar, Shalini and Sundaram, Shanthy and Rai, G. K., Nutritional and Therapeutic Values of Stevia Rebaudiana: A Review, Journal of Medicinal Plants Research, vol. 7, no. 46, pp. 3343--3353, December 2013. doi: 10.5897/JMPR2013.5276. Abstract
     Stevia rebaudiana is a nutrient rich natural sweetest plant of Asteraceae family. The leaves naturally contain diterpene glycosides stevioside, rebaudiosides A-F, steviolbioside and dulcoside, which are responsible for its sweet taste and have commercial value all over the world as sugar substitute in foods, beverages or medicines. It is a plant which offers sweetness with fewer calories and do not show any side effects after consumption on human health. Stevia has many pharmacological and therapeutic applications as suggested by many preclinical and some clinical studies; these are nontoxic and possess antioxidant, antimicrobial, antifungal and anticarcinogenic activity. In future Stevia is likely to become a major source of high potency low calorie sweetener for growing natural food market. This review article presents beneficial role of Stevia and its metabolites on health promoting properties. Key words: Stevia rebaudiana, steviosides, sweetner.
194. Kennelly, Edward J., Sweet and Non-Sweet Constituents of Stevia Rebaudiana, pp. 19, November 2001. doi: 10.1201/9780203165942-12. Abstract
     Stevia rebaudiana has been studied in depth because this plant is the source of several well-known sweettasting compounds. Interest in using S. rebaudiana as a commercial sweetener, especially by the Japanese food industry, has led to extensive phytochemical investigations of the herb’s constituents. To date more than 100 compounds have been identified from this species. The best known of these are the sweet-tasting ent-kaurene diterpenoid glycosides, particularly stevioside and rebaudioside A. Various review articles have appeared regarding the constituents of S. rebaudiana. Many review articles on the constituents of S. rebaudiana have been written in Japanese (Abe and Sonobe 1977; Morita 1977; Okazaki et al. 1977; Tanaka 1987; Yoshihira et al. 1987). Among the more comprehensive reviews in English of the Stevia constituents include those by Kinghorn and Soejarto (1985) and Hanson and De Oliveira (1993). A brief review of Stevia constituents by Crammer and Ikan (1986), and a more extensive treatment on the rebaudiosides (Crammer and Ikan 1987), have been published. Many other reviews of S. rebaudiana discuss the sweet-tasting constituents specifically, such as those byTanaka (1980; 1982), Salvatore et al. (1984), Bakal and O’Brien Nabors (1986), Phillips (1987) and Kinghorn and Soejarto (1991). There are additional reviews written in Chinese (Wu 1987), German (Seidemann 1976), and Italian (Toffler and Orio 1981). Of historical interest are the early reviews of Stevia by Robert (1915), Bell (1954), Fletcher (1955) and Jacobs (1955) that were written before the ultimate structural elucidation of stevioside.
195. Azizan, Nur Izzati, Colchicine Induced Mutation and Enhancement of the Steviol Glycoside Content in Stevia Rebaudiana / Nur Izzati Azizan, December 2020. url: https://ir.uitm.edu.my/id/eprint/60401/. Abstract
     Stevia rebaudiana is a sweet herb that belongs to the family Asteraeae. Steviol glycoside, a natural sweetener derived from Stevia leaves are 100-300 times sweeter than sucrose and contain a complex mixture of sweet diterpene glycoside. the mutagenic effect of colchicine to improve leaf and steviol glycosides yield in stevia was investigated. Stevia plant were treated with five different colchicine concentrations (0.5\%, 1.00\%, 1.50\%, 2.0\%, 2.5\% and 0.0\% act as control) for 48h. The plants were arranged in a completely randomized block design. Treated plants were characterized based on morphological traits such as plant height, leaf length and leaf thickness. The results obtained revealed significant difference (p≤0.05) in the morphological traits of the mutants when compared with the control. Overall, 2.00\% colchicine concentrations resulted in higher average plant height by 36.0\% ±0.6 leaf length increments by 43.0\%± 0.7 and the leaf thickness increment by 5.0\%±0.1. The improvement of the mutants' traits is concentration dependent and increases with increment in colchicine concentration. Therefore it is suggested that 2.0\% concentration should be applied in improving stevia growth and yield related traits.
196. Lucho, Simone Ribeiro and {do Amaral}, Marcelo Nogueira and {López-Orenes}, Antonio and Kleinowski, Alítcia Moraes and {do Amarante}, Luciano and Ferrer, María Ángeles and Calderón, Antonio Asensio and Braga, Eugenia Jacira Bolacel, Plant Growth Regulators as Potential Elicitors to Increase the Contents of Phenolic Compounds and Antioxidant Capacity in Stevia Plants, Sugar Tech, vol. 21, no. 4, pp. 696--702, August 2019. doi: 10.1007/s12355-018-0673-4. Abstract
     Stevia rebaudiana Bertoni is mainly used as a sweetener in many countries without any reported negative effects on health. This species is also abundant in phenolic compounds, which makes this plant a good candidate to satisfy the growing demand of natural sources for sweeteners and antioxidant compounds. Exogenously applied plant growth regulators (PGRs), acting as elicitors, influence the biosynthetic pathways of secondary metabolites. In this context, methyl jasmonate (MeJa), spermidine (SPD), salicylic acid (SA), and paclobutrazol (PBZ) (100~µM) were applied to stevia plants growing in a hydroponic system to assess their effects on temporary changes (at 24, 48, and 96~h) of antioxidant capacity and phenolic compounds (total soluble phenols, flavonoids, and hydroxycinnamic acids) levels. Overall, it was observed that MeJa increased total soluble phenolic content and antioxidant activity in extracts from Stevia leaves. By contrast, the addition of SPD, SA, and PBZ did not show a significant increase in any of the evaluated parameters. The results also showed a positive and strong correlation between phenolic compounds contents and antioxidant capacity. In short, results suggest that the application of MeJa could be a feasible way to enhance the biosynthesis of high added value phytochemicals that have notable antioxidant properties, and consequently potential health benefits, in stevia plants.
197. Lee, Soo Yee and Shaari, Khozirah, LC–MS Metabolomics Analysis of Stevia Rebaudiana Bertoni Leaves Cultivated in Malaysia in Relation to Different Developmental Stages, Phytochemical Analysis, vol. 33, no. 2, pp. 249--261, 2022. doi: 10.1002/pca.3084. Abstract
     Introduction Stevia is known for its sweet taste, attributed to the presence of steviol glycosides. Although reports on the dynamic changes of steviol glycosides during development of stevia are available, the data are mainly focused on stevioside and rebaudioside A. Information concerning the comprehensive metabolite profile of stevia in relation to different developmental stages is still lacking. Objective This study investigated the metabolite changes along the developmental stages of a local stevia cultivar. Methodology Stevia leaves were harvested at 4 different developmental stages (early vegetative, late vegetative, budding, and flowering). Samples were then subjected to LC–MS metabolomics analysis to determine the metabolite variations. Results A total of 55 metabolites, comprising phenolic acids, flavonoids, and terpenoids were identified by MS/MS analysis of the stevia leaf extracts, revealing a metabolite profile which was comparatively similar with those of cultivars grown in other countries. PLS-DA differentiated the early vegetative stage stevia leaf samples from those of the later stages by higher content of phenolic acids. The leaf metabolomes of the later 3 stages (late vegetative, budding, and flowering) were collectively richer in flavonoids. Meanwhile, the content of steviol glycosides is highest during the late vegetative and budding stages. Conclusion The present study provided, for the first time, a general overview of the metabolite variations with regard to the different developmental stages of stevia. The information may facilitate decision making of suitable harvesting times for higher yields of steviol glycosides or a more balanced metabolite profile in terms of pharmacologically useful metabolites.
198. Brandle, J. E. and Rosa, N., Heritability for Yield, Leaf:Stem Ratio and Stevioside Content Estimated from a Landrace Cultivar of Stevia Rebaudiana, Canadian Journal of Plant Science, vol. 72, no. 4, pp. 1263--1266, October 1992. doi: 10.4141/cjps92-159.