F. Ahmad et al., “Effect of Different Pruning Times on the Yield of Tea,” 2014.
This experiment was conducted at National Tea Research Institute, Shinkiari, Mansehra-Pakistan during 2010-11 with the objectives to find out the most suitable time for pruning of tea to get high production of fresh tea leaves. Mature tea bushes of Qi-men variety were top pruned manually with shears on 10th November, 10th December, 2010, 10th January, 10th February, and 10th March, 2011 with one month interval. November, December and January pruning recorded the 1st plucking on 3rd May, 2011 while the first plucking in the tea bushes pruned during March, 2011 was obtained on 13t h May 2011 with ten days delay as compared to early pruning. Pruning in December gave 3403 and 3292 kg more fresh tea leaves production ha-1 as compared to March and February pruning, respectively. A gradual decline was observed in plucking density points, shoot growth, fresh tea leaves yield and black tea production in plots pruned after December. It was found that the tea bushes pruned on 10th December, 2010 recorded significantly the highest number of plucking points m-2 (305.26), shoot growth (95.8 cm), fresh tea leaves yield (17888 kg ha-1) and black tea (3563 kg ha-1) followed by 10th January, 2011 pruning regarding these parameters, while the pruning on 10th March, 2011 produced the minimum number of plucking points m-2 (246.82), shoot growth (76.7 cm), fresh tea leaves yield ( 14486 kg ha-1) and black tea (2912 kg ha-1). Higher shoot density and shoot growth were associated with higher fresh tea leaves and made tea production. On the basis of these findings, it can be concluded that top pruning of tea during December and January gave the highest production of fresh leaves and black tea under the climatic conditions of Mansehra-Pakistan.
M. E. Amiri and M. H. Asil, “Determination of Optimum Harvestable Length of Shoots in Tea (Camellia Sinensis L.) Based on the Current Shoot Growth, Rather than Interval Plucking,” 2007.
This study was conducted to compare the quantity and quality of black tea (Camellia sinensis clone 100) yield by different manual plucking harvesting. Comparison the plucking method based on three lengths (5, 10 and 15 cm) of current shoot after regular annual pruning, with the standard conventional plucking in three flushing periods (spring, summer and fall) in a Randomized Complete Block Design (RCBD) experiment with four replications under environmental conditions of north of Iran during 2002 to 2003. Parameters including fresh weight of green leaves (as yield), canopy area, soluble and insoluble ash, % tannin, % caffeine, theaflavins (TF), % thearubigins (TR), ratio TR/TF in black tea, total color (TC) and brightness (BR) were measured. Black tea quality factors such as total theaflavins, thearubigins and total colour decreased with course of plucking (i.e., increasing yield quantity), while there was a positive relationship between increasing yield per bush and increasing canopy area of each bush. The highest amount (2420 g bush-1) for green leaves yield and the widest canopy area (7247 cm2 bush-1) were obtained in the 5 cm treatment in spring flush, followed by 10 and 15 cm respectively. The quantity and quality (compounds which contribute to black tea quality) fluctuated by the seasonal growth (spring, summer and fall) and variation of shoot length. The variability in caffeine and tannine was not significant, whereas the variability in TF ranging from 0.89 to 1.8% and for TR ranging from 9.9 to 14.1% for black leaf tea indicated a quality difference among the shoot lengths for plucking in spring flushing. The brightness (BR) in black tea leaf ranged from 21.4 to 24.6% with an average of 24% in spring flushing, and total colour (TC) varied from 4.1 to 5.2% with an average of 4.5%, indicating that brightness, colour and flavor index decreased when TR/TF decreased.
Z. Apostolides, H. E. Nyirenda, and N. I. K. Mphangwe, “Review of Tea (Camellia Sinensis) Breeding and Selection in Southern Africa,” International Journal of Tea Science, vol. 5, no. 01 and 02, pp. 13–19, Jun. 2006.
doi: 10.20425/ijts.v5i1and2.4783.
Historically tea seeds were imported into Southern Africa that belonged to either the sinensis or assamica varieties. Later on vegetatively propagated hybrid cultivars selected from F1 progeny raised from a deliberate hybridization programme between selected parents with desirable characteristics on the basis of quality and yield related parameters have been used in establishing tea plantations. New high throughput screening methods including biochemical and molecular markers are being investigated to improve the selection process and eliminate genotypes with poor quality potential before the expensive mini manufacture stage. A call is made for the establishment of a Global Tea Research Project to address common problems.
M. H. Asil, “Effects of Plucking Methods on Yield and Quality of Black Tea (Camellia Sinensis L.),” Journal of food, agriculture & environment, 2008.http://www.world-food.net/scientificjournal.php.
Comparative plucking method is based on three lengths (5, 10 and 15 cm) and control treatment (immediately after bases of pruning) after regular annual pruning by standard conventional plucking in three flushing period (spring, summer and autumn) in a randomized complete block design (RCBD) with four replications from 2005 to 2006. Parameters included green leaves, canopy area, % soluble ash, insoluble ash, % theaflavins (TF), % thearubigins (TR), % tannin (TN), % caffeine (CF), % brightness (BR), % total color (TC) and ratio TF/TR were measured. Plucking based on the lengths of shoot growth was significantly (p >or= 0.05) better than those based on the standard conventional plucking. The best result of green leaves yield and quality were obtained in the 5 cm treatment in spring flush, followed by 10 cm and 15 cm respectively. The quantity and quality (the biochemical constituents such as catechin fractions) and other compounds contributed to quality in black tea fluctuated by the seasonal growth (spring, summer and autumn) and variation of shoot length. The variability of TF, ranging from 0.72 to 1.10% in black tea indicates a difference in quality of tea. The solubility of TR ranging from 9.76 to 15.10% indicates that permeability in black tea was variable. The solubility of total polyphenols was a useful quality index of the black tea. Catechin levels in black tea, TF, BR, TR, TC, flavour index and sensory evaluation decreased by coarse plucked standard. BR and total colour decreased as TR decreased.
J. Balasuriya, “Shoot Population Density and Shoot Weight of Clonal Tea (Camellia Sinensis) at Different Altitudes in Sri Lanka,” European Journal of Agronomy, vol. 11, no. 2, pp. 123–130, Aug. 1999.
doi: 10.1016/S1161-0301(99)00024-6.
The production of shoots and mean dry weight of a harvested shoot of two tea clones, TRI 2023 and TRI 2025, were examined during a period of 27 weeks at five sites across an altitudinal range of 30 to 1859m. An increase in mean air temperature with decrease in altitude lowered the shoot population density (SPD) but increased the mean dry weight of the harvested shoot in both clones. Clone TRI 2023 had the largest SPD (3854–5115shootsm−2) while clone TRI 2025 had the heaviest shoot (0.2–0.32g) across the test altitudinal range. The increase in altitude significantly decreased (p<0.001) the number of harvested shoots per square metre in the centre of the plucking surface of clone TRI 2023 but increased the same in clone TRI 2025. However, the number of shoots harvested per square metre from the entire plot remained unchanged in clone TRI 2023 while this in TRI 2025 increased by 53% (p<0.001) when altitude rose from 30 to 1859m. Both clones showed the occurrence of ‘low yielding edges’ in the plucking surface of a bush, though in clone TRI 2023 this was greatly reduced with the increase in altitude. The shoot population density, density of harvested shoots and mean shoot dry weight are discussed in relation to yield at the five test altitudes.
S. Banerjee and J. Chatterjee, “Efficient Extraction Strategies of Tea (Camellia Sinensis) Biomolecules,” Journal of Food Science and Technology, vol. 52, no. 6, pp. 3158–3168, Jun. 2015.
doi: 10.1007/s13197-014-1487-3.
Tea is a popular daily beverage worldwide. Modulation and modifications of its basic components like catechins, alkaloids, proteins and carbohydrate during fermentation or extraction process changes organoleptic, gustatory and medicinal properties of tea. Through these processes increase or decrease in yield of desired components are evident. Considering the varied impacts of parameters in tea production, storage and processes that affect the yield, extraction of tea biomolecules at optimized condition is thought to be challenging. Implementation of technological advancements in green chemistry approaches can minimize the deviation retaining maximum qualitative properties in environment friendly way. Existed extraction processes with optimization parameters of tea have been discussed in this paper including its prospects and limitations. This exhaustive review of various extraction parameters, decaffeination process of tea and large scale cost effective isolation of tea components with aid of modern technology can assist people to choose extraction condition of tea according to necessity.
T. Benti, A. Debela, Y. Bekele, and S. Suleman, “Effect of Seasonal Variation on Yield and Leaf Quality of Tea Clone (Camellia Sinensis (L.) O. Kuntze) in South West Ethiopia,” Heliyon, vol. 9, no. 3, p. e14051, Mar. 2023.
doi: 10.1016/j.heliyon.2023.e14051.
P. Berjak, C. W. Vertucci, and N. W. Pammenter, “Effects of Developmental Status and Dehydration Rate on Characteristics of Water and Desiccation-Sensitivity in Recalcitrant Seeds of Camellia Sinensis,” Seed Science Research, vol. 3, no. 3, pp. 155–166, Sep. 1993.
doi: 10.1017/S0960258500001732.
The effect of rate of dehydration was assessed for embryonic axes from mature seeds of Camellia sinensis and the desiccation sensitivity of axes of different developmental stages was estimated using electrolyte leakage. Rapidly (flash) dried excised axes suffered desiccation damage at lower water contents (0.4 g H2O (g DW)−1) than axes dried more slowly in the whole seed (0.9 g H2O (g DW)−1). It is possible that flash drying of isolated axes imposes a stasis on deteriorative reactions that does not occur during slower dehydration. Differential scanning calorimetry (DSC) of the axes indicated that the enthalpy of the melting and the amount of non-freezable water were similar, irrespective of the drying rate.Very immature axes that had completed morphogenesis and histodifferentiation only were more sensitive to desiccation (damage at 0.7 g H2O (g DW)−1) than mature axes or axes that were in the growth and reserve accumulation phase (damage at 0.4 g H2O (g DW)−1). As axes developed from maturity to germination, their threshold desiccation sensitivity increased to a higher level (1.3−1.4 g H2O (g DW)−1). For the very immature axes, enthalpy of the melting of tissue water was much lower, and the level of non-freezable water considerably higher, than for any other developmental stage studied.There were no marked correlations between desiccation sensitivity and thermal properties of water. Desiccation sensitivity appears to be related more to the degree of metabolic activity evidenced by ultrastructural characteristics than to the physical properties of water.
A. Bhattacharya, P. K. Nagar, and P. S. Ahuja, “Seed Development in Camellia Sinensis (L.) O. Kuntze,” Seed Science Research, vol. 12, no. 1, pp. 39–46, Mar. 2002.
doi: 10.1079/SSR200196.
Seed development of tea was studied to identify the maturity index and the optimal time of seed collection. After harvest, the moisture content (28–30%fresh weight basis) of mature seeds, which germinated 100%, declined progressively (19% moisture content) after shedding, with a decrease in seed germination and viability. However, this viability loss could be prevented to some extent by storing seeds within intact fruits. The maximum rate of seed dry matter accumulation coincided with the accumulation of starch in the embryos and seeds at stage 8, the embryo maturation phase. Although the embryo abscisic acid (ABA) content was highest at stage 8, free ABA declined in the tea embryos throughout the remainder of the seed maturation cycle.
J. K. Bore, D. K. Isutsa, F. M. Itulya, and W. K. Ng’etich, “Effects of Pruning Time and Resting Period on Total Non-Structural Carbohydrates, Regrowth and Yield of Tea (Camellia Sinensis L.),” The Journal of Horticultural Science and Biotechnology, vol. 78, no. 2, pp. 272–277, Jan. 2003.
doi: 10.1080/14620316.2003.11511617.
An experiment was conducted at Kipkebe Estate, Sotik, Kenya, with the aim of establishing the effects of pruning time and resting period on total non-structural carbohydrate (TNC) reserves, regrowth and yield of tea. In this experiment, tea bushes were freely left unplucked for 45 and 90.d before pruning. Control treatments were continuously plucked until pruning. Results showed that TNC was significantly (P≤0.05) increased at pruning time. October pruning significantly increased leaf, stem, and root TNC. A longer resting period of 90.d significantly increased leaf and root TNC to 294 and 230.gkg–1, respectively. Generally, TNC declined after pruning and thereafter increased. Root TNC significantly correlated with regrowth period, diebacks and yield. Generally, the best resting period for increased TNC, regrowth and yield, is between 45 and 90.d. The best pruning time is October, if drought stress can be avoided.
P. J. Burgess, M. K. V. Carr, F. C. S. Mizambwa, D. J. Nixon, J. Lugusi, and E. I. Kimambo, “Evaluation of Simple Hand-Held Mechanical Systems for Harvesting Tea (Camellia Sinensis),” Experimental Agriculture, vol. 42, no. 2, pp. 165–187, Apr. 2006.
doi: 10.1017/S0014479705003352.
Over an eight-year period, harvesting methods based on simple mechanical aids (blade and shear) were evaluated against hand harvesting on mature morphologically contrasting tea clones in Southern Tanzania. The effects of shear step height (5–32 mm) and the harvest interval (1.8–4.2 phyllochrons) were also examined. Except in the year following pruning, large annual yields (5.7–7.9 t dry tea ha−1) were obtained by hand harvesting at intervals of two phyllochrons. For clones K35 (large shoots) and T207 (small shoots), the mean harvested shoot weights were equivalent to three unfurled leaves and a terminal bud. The proportions of broken shoots (40–48 %) and coarse material (4–6 %) were both relatively high. Using a blade resulted in similar yields to hand harvesting from K35 but larger yields from T207 (+13 %). The yield increase from clone T207 was associated with the harvest of more shoots and heavier shoots, smaller increases in canopy height, and a higher proportion (7–9 %) of coarse material compared to hand harvesting. On bushes, which had been harvested by hand for two years following pruning, using flat shears (no step) supported on the tea canopy resulted, over a three year period, in yields 8–14 % less than those obtained by hand harvesting and, for clone K35, a reduction in the leaf area index to below 5. The development of a larger leaf area index is made possible by adding a step to the shear. However, since annual yields were reduced by 40–50 kg ha−1 per mm increase in step height, the step should be the minimum necessary to maintain long-term bush productivity. As mean shoot weights following shear harvesting were about 13 % below those obtained by hand harvesting, there is scope, when using shears, to extend the harvest interval from 2 to 2.5 phyllochrons.
P. J. Burgess and M. K. V. Carr, “Responses of Young Tea (Camellia Sinensis) Clones to Drought and Temperature. I. Yield and Yield Distribution,” Experimental Agriculture, vol. 32, no. 3, pp. 357–372, Jul. 1996.
doi: 10.1017/S0014479700026296.
The yield response to drought and temperature of six contrasting tea clones was studied in a line-source irrigation experiment in Southern Tanzania. The selected clones, all commercially and/or scientifically important in eastern Africa, embrace a range of morphological and physiological types. The bushes were planted in August 1988 and differential drought treatments were imposed for 16 and 13 weeks towards the end of the dry seasons in 1990 and 1991, respectively. The resulting soil water deficits were successfully simulated using a water balance model. Under well-watered conditions Clone S15/10 (from Kenya) gave the highest yield of dry tea, reaching 5600 kg ha−l in the fourth year after planting (1991/92) compared with 3640–4420 kg ha−1 for the other five clones. During the cool season Clone SFS150 (from Malawi) yielded more than Clones 1, 207, 6/8 and K35. Although annual yields decreased curvi-linearly as the maximum soil water deficit increased, single values for the drought sensitivity of each clone could be derived by using stress time as an index of drought. On this basis Clones S15/10 and 207 were identified as being the most sensitive to drought; Clones SFS150 and 1 were drought resistant. The reasons for these differences in yield responses and the importance of determining drought sensitivity over an appropriate time period are discussed.
Plant growth-promoting rhizobacteria are able to exert a beneficial effect upon plant growth. Therefore, this study was conducted in order to investigate the effects of mineral fertilizer and one commercial liquid bio-fertilizer, and eight in three multi-traits rhizobacteria based bio-formulations on tea growth, nutrient uptake, chlorophyll contents and enzyme activities under acidic field soil conditions, in two years. The inoculation with multi-traits rhizobacteria enhanced different enzymes, such as, glutathione reductase, glutathione S-transferase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, polyphenol oxidase, peroxidase, and 5-dehydroshikimate reductase, and alcohol dehydrogenase, in tea leaves. Bacterial combinations efficiency was variable and depended on the inoculants strain and parameters evaluated. Bio-fertilizers formulations stimulated overall plant growth, including shoot development, leaf area, fresh and dry leaf yields, macro- and micro-nutrient uptake, chlorophyll and anthocyanin contents, and activities of oxidative, catalytic, hydrolytic and anti-oxidative enzymes of tea plants. In this study indicate that a higher enzyme activities and yield potential can be expected from acidic soils with some new bio-fertilizers formulations.
M. K. V. Carr, “The Role of Water in the Growth of the Tea (Camellia Sinensis) Crop: A Synthesis of Research in Eastern Africa. 1. Water Relations,” Experimental Agriculture, vol. 46, no. 3, pp. 327–349, Jul. 2010.
doi: 10.1017/S0014479710000293.
With a focus on eastern Africa, the results of research on the ecophysiology and water relations of tea are reviewed. In particular, work undertaken at the Ngwazi Tea Research Station (formerly Unit) in southern Tanzania is synthesized and interpreted in relation to work reported from elsewhere in Africa (and beyond where appropriate). Topics covered include factors influencing: the components of yield, yield distribution, root growth, stomatal behaviour, photosynthesis, transpiration, xylem water potential and how cultivars vary in their responses to water stress. A companion paper (Carr, 2010) reviews the results of research on the irrigation of tea, water productivity, and its practical significance to the tea industry and the wider scientific community.
M. K. V. Carr, M. O. Dale, and W. Stephens, “Yield Distribution in Irrigated Tea (Camellia Sinensis) at Two Sites in Eastern Africa,” Experimental Agriculture, vol. 23, no. 1, pp. 75–85, Jan. 1987.
doi: 10.1017/S0014479700001150.
The results of two tea irrigation experiments conducted independently in southern Tanzania and Malawi, where severe annual droughts of similar duration occur, were compared. There were marked differences in the dry season yield distributions between the two sites. These could be attributed to the adverse effects of large saturation deficits on plant water status and rates of shoot extension in Malawi. The implications for tea irrigation in particular and for irrigation agronomy experiments in general are discussed. The need to include detailed descriptions of the environment in which experiments are conducted is stressed.
U. Chakraborty, G. Das, and B. N. Chakraborty, “Factors Influencing Spore Germination, Appressoria Formation and Disease Development inCamellia Sinensis byGlomerella Cingulata,” Folia Microbiologica, vol. 40, no. 2, pp. 159–164, Apr. 1995.
doi: 10.1007/BF02815415.
Factors associated with conidial germination and appressoria formation ofGlomerella cingulata causing the brown blight disease of tea (Camellia sinensis) were studiedin vitro. Spore germination and appressoria formation were optimum at a temperature of 25°C, pH 5.0, 7 h light/day regime and a 24-h incubation period. At a concentration of conidia of 1200/μL 10-d-old culture,G. cingulata exhibited a maximum germination and appressoria formation. A maximum production of lesions was also evident on detached tea leaves at this spore concentration and in diffuse light. Diffusates of a phenolie nature collected from tea varieties susceptible and resistant toG. cingulata inhibited spore germination and appressoria formation. Diffusates from resistant varieties were more fungitoxic than those from susceptible varieties. Some phenolics known to be present in tea leaves, when testedin vitro, exhibited varying degrees of fungitoxicity. Pyrogallol totally inhibited spore germination, while pyrocatechol and phloroglucinol completely inhibited appressoria formation.
E. W. C. Chan, E. Y. Soh, P. P. Tie, and Y. P. Law, “Antioxidant and Antibacterial Properties of Green, Black, and Herbal Teas of Camellia Sinensis,” Pharmacognosy Research, vol. 3, no. 4, pp. 266–272, 2011.
doi: 10.4103/0974-8490.89748.
Background: The role of non-polymeric phenolic (NP) and polymeric tannin (PT) constituents in the antioxidant and antibacterial properties of six brands of green, black, and herbal teas of Camellia sinensis were investigated. Materials and Methods: Total phenolic content (TPC) and ascorbic acid equivalent antioxidant capacity (AEAC) were assessed using the Folin-Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, respectively. Minimum inhibitory dose (MID) against Gram-positive Micrococcus luteus, Staphylococcus aureus, and Bacillus cereus, and Gram-negative. Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa was assessed using the disc-diffusion method. Teas were extracted with hot water successively three times for one hour each time. The extracts were fractionated using Sephadex LH-20 column chromatography to obtain the NP and PT constituents. Results: Extraction yields ranged from 12 to 23%. Yields of NP fractions (70–81%) were much higher than those of PT fractions (1–11%), suggesting that the former are the major tea components. Ranking of antioxidant properties of extracts was green tea>black tea>herbal tea. For all six teas, antioxidant properties of PT fractions were significantly higher than extracts and NP fractions. Extracts and fractions of all six teas showed no activity against the three Gram-negative bacteria. Green teas inhibited all three Gram-positive bacteria with S. aureus being the least susceptible. Black and herbal teas inhibited the growth of M. luteus and B. cereus, but not S. aureus. The most potent were the PT fractions of Boh Cameron Highlands and Ho Yan Hor with MID of 0.01 and 0.03 mg/disc against M. luteus. Conclusion: Results suggested that NP constituents are major contributors to the antioxidant and antibacterial properties of teas of C. sinensis. Although PT constituents have stronger antioxidant and antibacterial properties, they constitute only a minor component of the teas.
P. Chaudhuri and S. K. S. Jamatia, “Impact of Rubber Leaf Vermicompost on Tea (Camellia Sinensis) Yield and Earthworm Population in West Tripura (India),” Agricultural Science Digest - A Research Journal, no. Of, Feb. 2021.
doi: 10.18805/ag.D-5234.
Background: Vermicompost is a manure produced from organic waste through the activity of epigeic earthworms and microbes. Excessive use of chemical fertilizers for long term to increase the crop productivity have led to deterioration of soil health. Therefore, to assess the effect of vermicompost, as an alternative option to chemical fertilizer, on tea yield and earthworm population, field application of vermicompost on tea plantation was carried out for a period of two years (2015-2016) in Harishnagar Tea Estate, West Tripura, India. Methods: The experimental plot (25 sq. m) was set up using a random block design with 4 different rates of vermicompost viz. T0 (Control), T1 (5 t ha-1 year-1), T2 (10 t ha-1 year-1) and T3 (15 t ha-1 year-1) each having five replications. Composite soil samples were collected at the beginning and at the end of the experiment. Earthworms were also collected during the experimental period.Conclusion: Application of vermicompost significantly influenced the tea plantation soils, increased the tea yield along with earthworm population and was dependent on the vermicompost doses applied.
R. Chaudhury, S. Lakhanpaul, and K. P. S. Chandel, “Germination and Desiccation Tolerance of Tea (Camellia Sinensis (L.) O. Kuntze) Seeds and Feasibility of Cryopreservation.,” Sri Lanka Journal of Tea Science, vol. 59, no. 2, pp. 89–94, 1990.https://www.cabdirect.org/cabdirect/abstract/19921632704.
Tea seeds are large, with a moisture content of around 40% (fresh weight) at the time of shedding. Desiccation to no less than 24% moisture ensured seed survival. Rehydration aided germination of seeds dried to 23% moisture but exposure to liquid nitrogen prevented survival. None of the cryoprotectants used (glycerol, DMSO and PEG 6000) were effective.
Z. X. Chen, Q. Y. Lan, L. Zheng, Y. X. Bao, and Y. L. Luo, “Effects of Dehydration and Temperature on Seed Viability and Antioxidative Enzymes Activities on Three Kinds of Cultivars of Camellia Sinensis,” Brazilian Journal of Botany, vol. 38, no. 3, pp. 497–504, Sep. 2015.
doi: 10.1007/s40415-015-0167-5.
The paper studied germination characteristics, dehydration sensitivities, and antioxidative enzyme activities of seeds in three varieties of Camellia sinensis L. [C. sinensis var. sinensis cv. Fuding-dabaicha (Fd), C. sinensis var. assamica cv. Menghai-dayecha (Md), and C. sinensis var. assamica cv. Yunkang 10 (Y10)] during desiccation. The optimum germination temperature was 25 °C for Fd, 30 °C for Md, and 20 °C for Y10. Md, Y10, and Fd seeds were allsensitive to dehydration. GPs of three cultivars decreased dramatically after dehydration for 144 h, reaching values of 48, 37, and 57 % for Md, Y10, and Fd when moisture content declined to 17.5, 17.4, and 14.4 %, respectively. The antioxidative enzymes in Md, Y10, and Fd seeds were not as effective as orthodox seeds, none of them can scavenge ROS timely. Thus, lipid peroxidation accelerated. There were differences between seeds of the three cultivars: Fd seeds were smaller in shape than the other two; Fd seeds showed lower sensitivity to dehydration than the other two; and H2O2 contents in Fd seeds were obviously lower than in Md and Y10 seeds, indicating that antioxidative enzymes in Fd seeds were more effective than the other two.
X. H. Chen et al., “Photosynthesis, Yield, and Chemical Composition of Tieguanyin Tea Plants (Camellia Sinensis (L.) O. Kuntze) in Response to Irrigation Treatments,” Agricultural Water Management, vol. 97, no. 3, pp. 419–425, Mar. 2010.
doi: 10.1016/j.agwat.2009.10.015.
Tieguanyin Oolong tea (Camellia sinensis (L.) O. Kuntze) is a name brand important commodity for Anxi county, Fujian province in China. Four-year-old tea plants at a tea plantation in Anxi were subjected to six different irrigation treatments (i.e. 5, 10, 15, 20, and 25d irrigation intervals for T1 to T5 with a rate of 3.5kg water per plant, plus a non-irrigated control). After 50d of irrigation treatments, leaf water potential was −1.70, −2.34, −2.48, −2.89, −3.55, and −4.92MPa for treatment T1, T2, T3, T4, T5, and control, respectively. Leaf biomass yield increased by 32.8%, 21.9%, and 21.3% for T1, T2, and T3, respectively, compared to control. The net photosynthesis (Pn), stomatal conductance (gs) and transpiration (E) decreased with irrigation interval increasing. Tea polyphenol (TP) and free amino acid (AA) decreased when the irrigation intervals were increased, but caffeine (CA) content apparently increased as the irrigation intervals were increased. To balance irrigation water demand and tea yield and quality, it is recommended that the irrigation interval should be set at 10d with a rate of 3.5kg water per plant for the optimal production in Anxi, Fujian province of China.
H. Chen et al., “Post Desiccation Germination of Mature Seeds of Tea (Camellia Sinensis L.) Can Be Enhanced by pro-Oxidant Treatment, but Partial Desiccation Tolerance Does Not Ensure Survival at −20°C,” Plant Science, vol. 184, pp. 36–44, Mar. 2012.
doi: 10.1016/j.plantsci.2011.12.006.
The maximal potential desiccation tolerance (MPDT) of tea (Camellia sinensis) seeds has been a matter of debate for decades. Here we assessed the ability of tea seeds from three sites in China to germinate after desiccation. Desiccation tolerance was greatest in Kunming, followed by Puer and Lincang, with Kunming seeds tolerating drying to 8% moisture content (MC), or ∼0.5 water activity (aw). Such tolerance was observed in Lincang seeds only when hydrogen peroxide (H2O2) at 0.5 or 1M was applied to seeds, indicating a stimulatory role for H2O2 in post-desiccation germination. Puer seeds exhibited MPDT of 16% MC (∼0.7 aw). Therefore, seeds from all three sites were not recalcitrant. The length of the dry season after dispersal and the high ratio of seed coat to seed mass (>0.3) support the observation of non-recalcitrant behaviour. The seeds were not immature, as the lipid signal in embryonic axes mirrored that of the cotyledons (30% oil). Even after high survival [>60% total germination (TG)] on drying to 10–13% MC, no Kunming seeds tolerated 1 month storage at −20°C coinciding with lipid transitional changes at this temperature. The results indicate that tea seeds from China are neither recalcitrant nor storable at −20°C.
Q. Chen, L. Yang, P. Ahmad, X. Wan, and X. Hu, “Proteomic Profiling and Redox Status Alteration of Recalcitrant Tea (Camellia Sinensis) Seed in Response to Desiccation,” Planta, vol. 233, no. 3, pp. 583–592, Mar. 2011.
doi: 10.1007/s00425-010-1322-7.
Tea seed is believed to be recalcitrant based on its sensitivity to chilling or drying stress. Reactive oxygen species (ROS) and alterations in cytosolic redox status have been implicated in intolerance to desiccation by recalcitrant seed, but there is little information available regarding how ROS are regulated in seeds susceptible to drying stress. We investigated changes in protein expression and activity in tea embryo in response to desiccation using physiological and proteomic methods. Results showed that desiccation treatment dramatically induced the accumulation of H2O2 in tea embryos, accompanied by increased activities of antioxidant enzymes like ascorbate peroxidase (APX) and superoxide dismutase (SOD). Proteomic analyses also demonstrated that 23 proteins associated with defense response, metabolism and redox status were up-regulated following desiccation. Increase in antioxidants, ascorbic acid (AsA) and catalase (CAT) (H2O2 scavengers) partially assuaged desiccation damage to tea seed, resulting in improved germination rates. Higher accumulation of H2O2 aggravated desiccation damage to seeds leading to lower germination activity. We propose that desiccation causes an over-accumulation of ROS that are not efficiently scavenged by increased levels of antioxidant enzymes. High levels of ROS alter the redox status and are detrimental to seed viability. Reducing ROS to appropriate concentrations is an efficient way to reduce desiccation damage and improve germination rates of recalcitrant seeds.
W. a. J. M. D. Costa, D. M. S. Navaratne, and A. Anandacoomaraswamy, “Physiological Basis of Yield Variation of Tea (Camellia Sinensis) During Different Years of the Pruning Cycle in the Central Highlands of Sri Lanka,” Experimental Agriculture, vol. 45, no. 4, pp. 429–450, Oct. 2009.
doi: 10.1017/S0014479709990482.
The objective of this study was to elucidate the physiological basis of the significant yield decline that occurs during the fourth year of the pruning cycle of tea. Biomass partitioning, which was hypothesized to be a major factor in causing this yield decline, was measured by destructive harvests of entire tea bushes, in two contrasting, mature, field-grown tea cultivars (TRI 2025 and DT1) at the end of different years of the pruning cycle. In both cultivars, yield showed continuous increases from year 1 to 3, followed by reductions of 44% and 35% in TRI2025 and DT1 respectively in the fourth year. Patterns of biomass partitioning to roots, stems or branches did not correlate with the above yield variation whereas harvest index, canopy leaf area index and mature leaf dry weight showed variations which paralleled the yield variation. The fourth-year decline in harvest index was brought about by reductions in both shoot number per m2 and mean individual shoot weight, which indicate a reduction in sink strength. Both cultivars showed reductions in light-saturated photosynthetic rate of maintenance foliage during the second half of the pruning cycle, indicating reduced source capacity. Hence, a combined reduction of both sink strength and source capacity during the fourth year could have brought about the significant yield reduction in tea. A significant increase of root starch in the fourth year indicated a down-regulation of physiological activities of the bush towards the end of the pruning cycle. Mechanisms responsible for this down-regulation need to be elucidated by further research.
C. Deng et al., “Metabolite and Transcriptome Profiling on Xanthine Alkaloids-Fed Tea Plant (Camellia Sinensis) Shoot Tips and Roots Reveal the Complex Metabolic Network for Caffeine Biosynthesis and Degradation,” Frontiers in Plant Science, vol. 11, p. 1339, 2020.
doi: 10.3389/fpls.2020.551288.
While caffeine is one of the most important bioactive metabolites for tea as the most consumed non-alcohol beverage, its biosynthesis and catabolism in tea plants are still not fully understood. Here, we integrated purine alkaloid profiling and transcriptome analysis on shoot tips and roots fed with caffeine, theophylline, or theobromine to gain further understanding of caffeine biosynthesis and degradation. Shoot tips and roots easily took up and accumulated high concentrations of alkaloids, but roots showed much faster caffeine and theophylline degradation rates than shoot tips, which only degraded theophylline significantly but almost did not degrade caffeine. Clearly feedback inhibition on caffeine synthesis or inter-conversion between caffeine, theophylline, and theobromine, and 3-methylxanthine had been observed in alkaloids-fed shoot tips and roots, and these were also evidenced by significant repression of TCS and MXMT genes critical for caffeine biosynthesis. Among these responsively repressed genes, two highly expressed genes TCS-4 and TCS-8 were characterized for their enzyme activity. While we failed to detect TCS-4 activity, TCS-8 displayed N-methyltransferase activities towards multiple substrates, supporting the complex metabolic network in caffeine biosynthesis in tea plants since at least 13 TCS-like N-methyltransferase genes may function redundantly. This study provides new insight into complex metabolic networks of purine alkaloids in tea plants.
D. Duan et al., “Regulation Mechanisms of Humic Acid on Pb Stress in Tea Plant (Camellia Sinensis L.),” Environmental Pollution, vol. 267, p. 115546, Dec. 2020.
doi: 10.1016/j.envpol.2020.115546.
Though the interaction between humic acid (HA) and heavy metals has been widely reported, the effects of HA on the toxicity of heavy metals to plants are still in debate. In this study, the regulation mechanisms of HA on Pb stress in tea plant (Camellia sinensis L.) was investigated through hydroponic experiments, and the experimental results were explained by using transmission electron microscope (TEM), scanning transmission X-ray microscopes (STXM) and isobaric tags for relative and absolute quantitation (iTRAQ) differential proteomics. Significant alleviation of Pb stress was found with HA coexistence. TEM results showed that HA greatly mitigated the damage of cells caused by Pb stress. Compared with sole Pb treatment, the addition of HA increased the contents of pectin and pectic acid in the cell wall by 10.5% and 30.5%, while arabinose (Ara) and galactose (Gal) decreased by 20.5% and 15.9%, respectively, which were beneficial for increasing Pb adsorption capacity of the cell wall and promoting cell elongation. Moreover, iTRAQ differential proteomics analysis proved that HA strengthened the antioxidant system, promoted the synthesis of cell wall, and stabilized protein and sulfur-containing substance metabolism in molecular level. Notably, the concentration of calcium (Ca) in the cell wall of HA coexistence treatment was 47.4% higher than Pb treatment. STXM results also indicated that the distribution of Ca in the cell wall was restored with the presence of HA. This might promote the formation of the egg-box model, thus alleviating Pb stress in cells. Our results reveal the regulation mechanisms of HA on Pb detoxification in plants and provide useful information for improving the safety of agricultural products.
R. Ellis and H. E. Nyirenda, “A Successful Plant Improvement Programme on Tea (Camellia Sinensis),” Experimental Agriculture, vol. 31, no. 3, pp. 307–323, Jul. 1995.
doi: 10.1017/S0014479700025485.
The tea industry in Malawi is the oldest in Africa but in the past had always produced poor quality tea. A plant improvement programme was therefore started in 1956 at the Tea Research Stations in Mulanje. The improvement in made tea quality was assisted by an investigation into the biochemistry of tea fermentation. Early success was obtained with polyclonal seed varieties and the development of clones from field bushes. These were used in cross breeding to produce new progeny clones which are showing a steady improvement in quality and yield. The need for improved yield was recognised as the programme progressed and appropriate selection procedures adopted. Techniques for improved vegetative propagation for field planting, grafting ofseed bearer trees and composite plants were developed. Liaison with the tea industry has been good and all new plantings in southern Africa since about 1975 have been with improved material. The programme is continuing and future prospects are good.
Twenty-four clones of tea [Camellia sinensis (L.) O. Kuntze] were investigated for genotypic association of six yield components, their effect on yield, and pluck quality value. The experiment was a completely randomized design with three replicates. Two yield components: weight of terminal bud and the first leaf were positively associated with yield. Path analysis showed that the value of genotypic correlation of terminal bud weight on yield (0.444) was similar to its direct effect (0.446). The weight of the first leaf showed maximum positive effect on yield. Hence, selection for higher yield in tea clones can be weight of terminal bud and first leaf in connection with tea quality selection. Differences in pluck quality values were significant (P = 0.05) among the tea clones studied. Clones UNK-1, 68, 228, 237, and 14 had the best pluck quality values in ascending order, while Clone 318 had the lowest.
R. Farhoosh, G. A. Golmovahhed, and M. H. H. Khodaparast, “Antioxidant Activity of Various Extracts of Old Tea Leaves and Black Tea Wastes (Camellia Sinensis L.),” Food Chemistry, vol. 100, no. 1, pp. 231–236, Jan. 2007.
doi: 10.1016/j.foodchem.2005.09.046.
The antioxidant activity of various extracts of old tea leaves (OTL) and black tea wastes (BTW) in comparison with that of green tea leaves (GTL) was evaluated. The highest extraction yield and antioxidant activity were found in hot water extracts of GTL. Hot water extracts of OTL and BTW showed the same statistically significant antioxidant activities (P<0.05). Also, there was no statistically significant difference between the antioxidant activities of OTL and BTW extracts obtained by the other two extraction methods (ethyl acetate and methanolic methods) and, in some cases, BTW extracts acted even better than OTL extracts. The antioxidant activity of tea extracts was not concomitant with the development of their reducing power. This suggested that the antioxidant activity of tea extracts likely involves other mechanisms in addition to those of reductones. Totally, BTW extracts had antioxidant activities comparable with or even better than those of OTL extracts. Hence, OTL and BTW, which are often considered as agricultural wastes, can be used as potent natural antioxidative sources.
K. O. George, T. Kinyanjui, J. Wanyoko, O. K. Moseti, and F. Wachira, “Extraction and Analysis of Tea (Camellia Sinensis) Seed Oil from Different Clones in Kenya,” African Journal of Biotechnology, vol. 12, no. 8, 2013.
doi: 10.4314/ajb.v12i8.
Kenyan tea (Camellia sinensis) is widely grown for its leaves and is commercialized as black tea. Product diversification and value addition is currently an area of great interest. This study provides data on the physico-chemical properties of Kenyan tea seed oil from selected clones of tea seeds to ascertain its potential applications. Soxhlet extraction using hexane was employed to obtain tea seed oil followed by chemical analysis to assess its properties. Oil yield, iodine value, saponification value, peroxide value, free fatty acids, total polyphenols and antioxidant activity were determined. The oil yields ranged between 16 to 25% w/w. Iodine value was in the range of 86 to 91 g I2/100 g, peroxide value < 3.5 meq O2/kg, saponification value between 182 to 187 mg KOH/g, free fatty acid < 1.5% oleic acid, total polyphenols 0.036 to 0.043 mg/L gallic acid and antioxidant activity of between 14 to 21% 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. Tea seed oil is stable and can be a potential source of natural antioxidants.Keywords: Tea seed oil, iodine value, saponification value, peroxide value, free fatty acids, total polyphenols, antioxidant activityAfrican Journal of Biotechnology Vol. 12(8), pp. 841-846
T. Gohain, A. C. Barbora, and A. Deka, “Effect of Manganese on Growth, Yield and Quality of Tea [Camellia Sinensis L. (O) Kuntez].,” Research on Crops, vol. 1, no. 1, pp. 91–97, 2000.https://www.cabdirect.org/cabdirect/abstract/20013040423.
To study the effect of different levels of manganese (Mn) on growth, yield and quality of tea, an experiment was conducted during 1994 to 1996 at Tocklai Tea Estate of Tocklai Experimental Station, TRA, Jorhat, Assam, with four levels of Mn (0, 5, 10 and 15 kg Mn/ha/year). Manganese showed significant influence on yield of tea recording the highest yield at 10 kg Mn/ha/year. A positive response...
F. S. Hamid, F. Ahmad, and S. Aslam, “Effect of Nitrogenous Fertilizer on the Growth and Yield of Tea (Camellia Sinensis L.) Pruned in Curved Vs Flat Shape,” J. Agric. Res., 2016.
D. He et al., “Magnesium Is a Nutritional Tool for the Yield and Quality of Oolong Tea (Camellia Sinensis L.) and Reduces Reactive Nitrogen Loss,” Scientia Horticulturae, vol. 308, p. 111590, Jan. 2023.
doi: 10.1016/j.scienta.2022.111590.
Magnesium (Mg) plays an important role in controlling the biological utilization and dispersion of nitrogen (N) in crops and the environment; however, the application of Mg fertilizer is often neglected in crop nutrient management globally. Can intensified Mg management optimize the agronomic and environmental benefits of tea production? To answer this question, four trials of Mg fertilizer levels in oolong tea (Camellia sinensis L.) garden were designed, i.e., 0 (Mg0), 35 (Mg1), 70 (Mg2) and 140 (Mg3) kg MgO ha−1 yr−1, and the tea yield and quality, N use efficiency (NUE) and reactive N losses were assessed. Compared with Mg0, Mg applications significantly increased tea yield by an average of 14.1% (spring tea), 18.4% (autumn tea) and 15.8% (annual total tea), improved tea quality, and increased the partial factor productivity of applied N (PFPN) and NUE by 13.9–17.2% and 17.8–25.5% after the four-year trial, respectively. The N uptake of young shoots (i.e., harvest part) in Mg1, Mg2 and Mg3 was higher than that in Mg0 by 19.5%, 25.8% and 21.5%, respectively. Simultaneously, Mg fertilization significantly decreased the N surplus and reduced the risk of reactive N loss. There was no significant difference in the indicators mentioned above or in the economic benefits among the Mg fertilizer treatments. In conclusion, if the risk of soil nitrate leaching is not considered, the recommended Mg application rate is 35 kg MgO ha-1 yr-1; otherwise, it is 70 kg MgO ha-1 yr-1. These results indicated that Mg could be a key limiting factor and have positive effects on tea production, and reasonable Mg fertilization is beneficial to the sustainability of tea production.
E. M. Herd and G. R. Squire, “Observations on the Winter Dormancy of Tea (Camellia Sinensis L.) in Malawi,” Journal of Horticultural Science, vol. 51, no. 2, pp. 267–279, Jan. 1976.
doi: 10.1080/00221589.1976.11514690.
In Malawi, over 80 % of the tea yield is harvested during the five months of the hot, wet, tropical summer. Characteristics of shoot growth were examined to define the nature of the fall in yield during the subsequent winter months of May to August. Slower shoot extension and more apical bud dormancy reduced the rate at which shoots reached harvestable size in winter. No changes were observed in other characteristics of shoot growth such as individual shoot weight, shoot death or dormancy of the axillary buds in their initial state. During the winter there was a stimulation of root growth and the low yield was possibly related in part to a redistribution of assimilate. Altering the photoperiod had little effect on yield but maintenance of warm night temperatures (20°C) during parts of the cold season accelerated the rate of shoot growth to a level as high as that of the hot, wet season.
M. Jamalomidi and M. Gholami, “Effect of Packing Type and Storage Time on Tea (Camellia Sinensis L.) Seed Germination.,” International Research Journal of Applied and Basic Sciences, vol. 4, no. 5, pp. 1323–1327, 2013.https://www.cabdirect.org/cabdirect/abstract/20133337513.
Tea seed is a recalcitrant seed with week storage ability. Of course, tea seed germination is affected by storage method and ambient conditions, storage time and genotype. In order to investigation of storage times, packaging types and environmental conditions in cellar effects on tea seed germination, an experiment was conducted using split plots experimental design with four replicates. Based...
H. a. S. L. Jayasinghe, L. D. B. Suriyagoda, A. S. Karunarathne, and M. A. Wijeratna, “Modelling Shoot Growth and Yield of Ceylon Tea Cultivar TRI-2025 (Camellia Sinensis (L.) O. Kuntze),” The Journal of Agricultural Science, vol. 156, no. 2, pp. 200–214, Mar. 2018.
doi: 10.1017/S0021859618000229.
The present study was aimed at stimulating the growth and yield of Sri Lankan tea cultivar TRI 2025 grown in different climatic regions in the country. The model was developed and calibrated using weather, crop and soil data collected from different climatic zones. The model is designed to simulate shoot replacement cycle, leaf area of a shoot, shoot growth, dry matter partitioning and tea shoot yield. The model was validated using shoot development and growth data not used for model calibration. These validation data were collected from low, mid and high elevations representing temperature and rainfall gradients in the country. Model calibration showed that thermal time required to initiate the fish leaf, 1st, 2nd and 3rd normal leaf in a tea shoot from the time of natural senescence of the scale leaves were 129, 188, 235, 296 °C days, respectively, and a tea shoot reached the harvestable stage after 393 °C days. The model simulated leaf area (cm2) and fresh weight (g/m2) of tea shoots at different developmental stages and locations which were in good agreement with the measured values at the validation stage (R2 > 0.92 and 0.98, respectively). Similarly, simulated shoot yields (g/m2/month) at the validation stage were strongly correlated with the measured values (n = 12, R2 > 0.58, RMSE = 5–17 g/m2/month). Thus, the model can be used to estimate the shoot yield of tea cultivar TRI 2025 grown in different climatic conditions in Sri Lanka. Areas requiring further improvements to the model are also discussed.
S. L. Jayasinghe and L. Kumar, “Potential Impact of the Current and Future Climate on the Yield, Quality, and Climate Suitability for Tea [Camellia Sinensis (L.) O. Kuntze]: A Systematic Review,” Agronomy, vol. 11, no. 4, p. 619, Apr. 2021.
doi: 10.3390/agronomy11040619.
Even though climate change is having an increasing impact on tea plants, systematic reviews on the impact of climate change on the tea system are scarce. This review was undertaken to assess and synthesize the knowledge around the impacts of current and future climate on yield, quality, and climate suitability for tea; the historical roots and the most influential papers on the aforementioned topics; and the key adaptation and mitigation strategies that are practiced in tea fields. Our findings show that a large number of studies have focused on the impact of climate change on tea quality, followed by tea yield, while a smaller number of studies have concentrated on climate suitability. Three pronounced reference peaks found in Reference Publication Year Spectroscopy (RYPS) represent the most significant papers associated with the yield, quality, and climate suitability for tea. Tea yield increases with elevated CO2 levels, but this increment could be substantially affected by an increasing temperature. Other climatic factors are uneven rainfall, extreme weather events, and climate-driven abiotic stressors. An altered climate presents both advantages and disadvantages for tea quality due to the uncertainty of the concentrations of biochemicals in tea leaves. Climate change creates losses, gains, and shifts of climate suitability for tea habitats. Further studies are required in order to fill the knowledge gaps identified through the present review, such as an investigation of the interaction between the tea plant and multiple environmental factors that mimic real-world conditions and then studies on its impact on the tea system, as well as the design of ensemble modeling approaches to predict climate suitability for tea. Finally, we outline multifaceted and evidence-based adaptive and mitigation strategies that can be implemented in tea fields to alleviate the undesirable impacts of climate change.
Z. Jian, C. Hao, and W. LiYuan, “Factors affecting the germination rate and the form in the culture of tea (Camellia sinensis) young embryos.,” Southwest China Journal of Agricultural Sciences, vol. 21, no. 2, pp. 440–443, 2008.https://www.cabdirect.org/cabdirect/abstract/20083184998.
A protocol was developed for the in vitro culture of young tea embryos. Low levels of auxin promoted embryo growth while high cytokinin rates inhibited germination. More than 80% of the young embryos continued to develop mature and sprout when cultured on MS media supplemented with 2.0 mg kinetin/litre + 0.1 mg IBA/litre + 1.0 mg GA3/litre. High levels of sucrose in the media would yield a high...
S. M. Kamunya et al., “Genomic Mapping and Testing for Quantitative Trait Loci in Tea (Camellia Sinensis (L.) O. Kuntze),” Tree Genetics & Genomes, vol. 6, no. 6, pp. 915–929, Dec. 2010.
doi: 10.1007/s11295-010-0301-2.
The tea industry is significant in the economies of tea-growing countries. Prospects of improving yield of made tea genomic information were explored using clones from a cross between clones TRFCA SFS150 and AHP S15/10. The 42 clones were tested in two distinct tea-growing regions in Kenya. Bulk segregant analysis was performed followed by complete genotyping. Out of 260 informative markers, 100 markers that showed 1:1 segregation were used to construct a linkage map. The map contained 30 (19 maternal and 11 paternal) linkage groups that spanned 1,411.5 cM with mean interval of 14.1 cM between loci. Based on the map, quantitative trait loci (QTL) analysis was done on yield data over 2003–2007 across the two sites, Timbilil and Kangaita. Twenty-three putative QTLs were detected, 16 in five different linkage groups for Timbilil, two in two groups for Kangaita, and the rest were associated with unassigned markers. No QTL was detected at both sites, which showed strong genotype\,× site interaction (G\,× E) but highly effective within-site heritability (\ {\hat{h}\^2} \\generally\,> 0.7). Problems of overestimated and spurious QTL effects arising from the smallness of the population should be mitigated by generally high within-site heritability. At least two unassigned markers associated with yield at Kangaita over the whole study period, suggesting potential as candidate markers for site-specific marker-assisted selections. Implications of the results with respect to mapping population, G\,× E, and marker-assisted selection are discussed.
S. M. Kamunya et al., “Quantitative Genetic Parameters in Tea (Camellia Sinensis (L.) O. Kuntze): I. Combining Abilities for Yield, Drought Tolerance and Quality Traits,” Afr. J. Plant Sci., vol. 3, no. 5, pp. 93–101, May 2009.
doi: 10.5897/AJPS.9000196.
The combining abilities for yield, drought tolerance and quality related traits in Camellia sinensis were estimated using a 4 x 4 full diallel mating design. There was significant phenotypic variation for the nine traits measured among the progeny and their parents. Generally, parents with good combining ability produced progeny with above average performance for all the traits evaluated. The general combining ability (GCA) effects were significant for all but one black tea quality trait, TF:TR, while specific combining ability (SCA) effects were significant for fermentability, pubescence and bud weight. All the traits but TF:TR however were predominantly governed by additive gene effects. Strong maternal influence for all traits was evident except for thearubigins and bud weight signifying the importance of the choice of female parents in tea breeding programmes targeting yield, abiotic stress related traits and processing of black tea and special tea products like the silvery tips. Significant non-additive effects were demonstrated by all traits apart from yield, TF:TR and bud weight. However, only drought tolerance, TF and pubescence exhibited unidirectional dominance effects. The results show that the assessed traits are highly heritable and guided breeding and judicious clonal selection would lead to further tea improvement. Although no trait can be treated singly, utilization of open pollinated seed targeted towards improvement of yield and black tea quality traits particularly high levels of total polyphenols and pubescence aimed at developing a designer clone for specialty tea product would suffice given judicious choice and inclusion of suitable progenitors in seed orchards. It is inferred that the basic information about combining abilities is valuable for breeding of elite cultivars.
C. W. Kayange, I. P. Scarborough, and H. E. Nyirenda, “Rootstock Influence on Yield and Quality of Tea (Camellia Sinensis L.),” Journal of Horticultural Science, vol. 56, no. 2, pp. 117–120, Jan. 1981.
doi: 10.1080/00221589.1981.11514975.
Rootstock influence on yield and quality of tea scions was studied on stub-grafted and chip-budded plants. Data collected over three seasons indicated that rootstock MFS 87 had significantly increased the yield of the scions PC I and SFS 204 but without significant effect on quality.
S. J. Kebeney, D. M. Kamau, C. O. Othieno, W. K. Ng’etich, and P. O. Owuor, “Changes in Soil Chemical Properties and Leaf Nutrients Content in Tea Due to Nitrogen Fertilizer Rates and Application Intervals.,” 2010.https://repository.maseno.ac.ke/handle/123456789/1710.
Tea (Camellia sinensis (L.) O. Kuntze) plant, requires much more nitrogen than most of the other nutrients for its growth, development and sustainability of harvestable crop. Soil as a resource of plant nutrients, cannot continuously and adequately provide all the essential plant nutrients due to the high nutrient removal through harvesting and expected losses from erosion and leaching. Therefore, to sustain production, regular fertilizer application is essential. There has been speculation that the one year fertilizer application interval may be too close and that longer application intervals could give similar yields and reduce on high fertilizer expenditures. A study where nitrogen as NPK(S) 25:5:5:5 fertilizer was applied at the rates of 0, 60 120, 180, 240 and 300 kg N per hectare per year at 12 months and 24 months intervals at Michimikuru, Nyambene Hills and at Kangaita, Kirinyaga was conducted to verify the speculation. Physical and chemical characteristics of soils showed the Michimikuru trial site soil was medium textured (sandy loam), acidic (pH 4.57) with high organic matter accumulation and, exchangeable bases with low extractable manganese. The Kangaita trial site soil showed coarse texture (loamy sand), very acidic (pH 3.61), low exchangeable bases and organic matter content but high extractable manganese. The soil pH levels at Michimikuru decreased significantly (P≤0.01) with increase in nitrogen rates with 24 months application interval being less acidifying by 0.15 pH units compared with the 12 months interval. The levels of exchangeable cations were significantly (P≤0.01) high and manganese reduced in soil solution (P≤0.01) down the soil profile. There was adequate supply of all the required nutrients for uptake by tea in both application intervals. The results suggest that the soil and leaf nutrients, particularly, nitrogen was adequate for the growth, development and sustainability of the tea plant at the longer application interval at Michimikuru. Kangaita on the other hand indicated that soil pH and exchangeable cations decreased with increase in nitrogen rates, down the soil profile.
S. Kieko and I. Masahiko, “The Function of Roots of Tea Plant (Camellia Sinensis) Cultured by a Novel Form of Hydroponics and Soil Acidification,” American Journal of Plant Sciences, vol. 2012, May 2012.
doi: 10.4236/ajps.2012.35078.
A novel form of hydroponic culture was employed to explore the physiological function of roots of a tea plant (Camellia sinensis). The pH of the nutrient solution with an actively growing tea plant decreased during cultivation. Furthermore, no oxalic acid, tartaric acid, malic acid or citric acid, all possible factors in acidification, was detected in the nutrient solution of a growing plant. A proton pump inhibitor suppressed the acidification of the solution. Soil acidification might have been accelerated with a proton released from ammoniacal nitrogen preferentially for the growth, suggesting the specific mechanism of tea plant as a functional food.
J. M. Kigalu, E. I. Kimambo, I. Msite, and M. Gembe, “Drip Irrigation of Tea (Camellia Sinensis L.): 1. Yield and Crop Water Productivity Responses to Irrigation,” Agricultural Water Management, vol. 95, no. 11, pp. 1253–1260, Nov. 2008.
doi: 10.1016/j.agwat.2008.05.004.
The effects of drip irrigation on the yield and crop water productivity responses of four tea (Camellia sinensis (L.) O. Kuntze) clones were studied four consecutive years (2003/2004–2006/2007), in a large (9ha) field experiment comprising of six drip irrigation treatments (labelled: I1–I6) and four clones (TRFCA PC81, AHP S15/10, BBK35 and BBT207) planted at a spacing of 1.20m×0.60m at Kibena Tea Limited (KTL), Njombe in the Southern Tanzania in a situation of limited water availability. Each clone×drip irrigation treatment combination was replicated six times in a completely randomized design with 144 net plots each with an area of 72m2. Clone TRFCA PC81 gave the highest yields (range: 5920–6850kg dried tea ha−1) followed by clones BBT207 (5010–5940kg dried tea ha−1), AHP S15/10 (4230–5450kg dried tea ha−1) and BBK35 (3410–4390kg dried tea ha−1) and drip irrigation treatment I2 gave the highest yields, ranging from 4954 to 6072kg dried tea ha−1) compared with those from other treatments (4113–5868kg dried tea ha−1). Most of these yields exceeded those (4200kg dried tea ha−1) obtained from overhead sprinkler irrigation system in Mufindi also Southern Tanzania, and Kibena Estate itself. Results showed that drip irrigation of tea not only increased yields but also gave water saving benefits of up to 50% from application of 50% less water to remove the cumulative soil water deficit (treatment I2), and with labour saving of 85% for irrigation. The yield of dried tea per mm depth of water applied, i.e., “the crop water productivity” for drip irrigation of clones TRFCA PC81, BBT207 and BBK35, in 2003/2004 for instance, were 9.3, 8.5 and 7.1kg dried tea [hamm]−1, respectively. The corresponding values in 2004/2005 were 2.7, 4.5 and 2.0kg dried tea [ha mm]−1 while the yield responses from clone AHP S15/10 were linear decreasing by 1 and 1.6kg dried tea [hamm]−1 in 2003/2004 and 2004/2005, respectively. In 2005/2006 the crop water productivity from clones TRFCA PC81, AHP S15/10, BBK35 and BBT207 were 4.5, 0.4, 5.2 and 6.9kg dried tea [hamm]−1, respectively with quadratic yield response functions to drip irrigation depth of water application. The results are presented and recommendations and implications made for technology-transfer scaling-up for increased use by large and smallholder tea growers.
J. M. Kigalu, “Effects of Planting Density and Drought on the Productivity of Tea Clones (Camellia Sinensis L.): Yield Responses,” Physics and Chemistry of the Earth, Parts A/B/C, vol. 32, no. 15, pp. 1098–1106, Jan. 2007.
doi: 10.1016/j.pce.2007.07.022.
Tea is an important cash crop in Tanzania, contributing over US$45million of annual exports and grown by over 30000 smallholder households, and a further 10000 people are employed by large estate producers. Over 70% of the national tea production comes from the Southern Highlands of Tanzania where expansion of tea estates under limited suitable land for tea is expected for the next two decades. Thus a client-demand driven field experiment was established in January 1993 to study and advice tea growers on the effects of plant density on the productivity and water use of young tea. The experiment comprised of two types of vegetative propagated tea plants (known as “clones”) of contrasting growth behaviour (AHP S15/10: spreading type and BBK35: erect), six plant densities (labelled D1: 8300plantsha−1 to D6: 83300plantsha−1) and seven irrigation or drought levels (labelled I0: un irrigated, to I6: well irrigated condition) as the treatments. Clone AHP S15/10, with larger crop cover than clone BBK35, consistently out-yielded clone BBK35 at all densities and under both well watered and drought stressed conditions. The corresponding yields from clone BBK35 were 2620 and 5960kgha−1. Reciprocal of yield per plant- and asymptotic yield–density relationships were used to explain these responses to density. Yields from clone AHP S15/10 during the period of drought treatments decreased as the maximum soil water deficit increased at all densities, but there were no yield responses to drought from clone BBK35 at the low densities. The study recommends planting densities of 20000 and 40000plantsha−1 for clones AHP S15/10, respectively for well irrigated conditions and a density of 20000plantsha−1 for both clones under un-irrigated environments.
R. Kumar, J. S. Bisen, M. Singh, and B. Bera, “Effect of Pruning and Skiffing on Growth and Productivity of Darjeeling Tea (Camellia Sinensis L.),” vol. 3, no. 3, 2015.
Pruning cycle is one of the most important operations in tea with a primary objective to replace the old set of maintenance foliage by a fresh one, so that tea bushes remain healthy and continue to provide succulent shoots to manufacture quality tea. An investigation was initiated in Experimental Farm, Darjeeling Tea Research and Development Centre, Kurseong, Dist. Darjeeling at 1347 m a.m.s.l on old chinary tea bushes to evaluate the suitability of pruning cycles of varying durations and pruning skiffing sequence on yield and crop distribution. Shoot extension rate, active and banjhi shoot (shoots with restricted growth), net photosynthetic rate, leaf water potential, leaf area distribution and tea yield were measured. Active shoot density decreased with age, with the corresponding increase in banjhi shoot density. Net photosynthetic rate and leaf water potential were highest during the first year and then decreased subsequently in all pruning cycles. Leaf area index (LAI) increased up to 3rd year in 4 and 5 year pruning cycles after pruning and reduced thereafter. The maximum yield was observed in 5 year pruning cycle in 3rd year after pruning and then reduced with pruning age. The yield of all pruning cycle were lowest in first year after pruning which may be attributed to small bushes with few branches and lower LAI. The maximum yield was also observed when pruned in December followed by November which may be due to maximum accumulation of root starch in December.
H. M. P. C. Kumarihami, E. U. Oh, A. Nesumi, and K. J. Song, “Comparative Study on Cross-Compatibility between Camellia Sinensis Var. Sinensis (China Type) and C. Sinensis Var. Assamica (Assam Type) Tea,” African Journal of Agricultural Research, vol. 11, no. 12, pp. 1092–1101, Mar. 2016.
doi: 10.5897/AJAR2015.9951.
Tea has long been a well-known crop for its economic value and widening the genetic variability of tea family is often necessitated. Hybridization programs at intraspecific level have been greatly fascinated as potential and useful methods in tea plant breeding to widening the genetic diversity. This comparative study was intended to explore a new avenue to develop the tea plant breeding programs through evaluating remote intraspecific cross-compatibility between Camellia sinensis var. sinensis (L.) O. Kuntze and C. sinensis var. assamica (Masters). Remote intraspecific cross-compatibility was assessed by comparing and contrasting the in-vivo pollen germination and pollen tube growth using fluorescence microscopy and the subsequent fruit set following controlled self- and cross-pollinations. In-vivo pollen germination and pollen tube growth was examined at 1 day, 3 days, and 14 days after pollination treatments, but disparity was not observed in pollen germination and pollen tube growth between self- and cross-pollinations. Early fruit set was evaluated at 3 months and 6 months after pollination. Fruit set was observed in cross-pollination except self-pollination. A late-acting self-incompatibility system or post-zygotic barriers and close intraspecific cross-compatibility were confirmed within C. sinensis var. sinensis (L.) O. Kuntze. Potential remote intraspecific cross-compatibility was recorded from cultivars crossed between China type and Assam type tea. The present findings bestow the significant contribution to develop the future tea breeding programs. Key words: Intraspecific cross, pollen germination, pollen quality, pollination, tea breeding.
J. Li, “The Effect of Plant Mineral Nutrition on Yield and Quality of Green Tea (Camellia Sinensis L.) under Field Conditions,” Doctor of Philosophy, Christian Albrechts University in Kiel, Kiel, Germany, 2005.https://macau.uni-kiel.de/receive/diss_mods_00001374.
Field experiments were conducted in 2002 and 2003 to study the responses of tea yield and quality to fertilization. The optimum N application rate of 810 kg N ha-1 a-1 was calculated from 95% of the maximum yield, which was closer to the N level at the lowest TP/AA. The critical soil Nmin in 0-60 cm soil depth was 200-260 kg N ha-1 (spring) and 320-430 kg N ha-1 (autumn), respectively. In spring, the critical NO3- contents were 30-33, 6-7 and 10-11 mg L-1 in the young stem, new fully expanded leaves (NFEL) and in the top old leaves, respectively. The critical AAN content was 714-732 mg L-1 in NFEL. In autumn, the critical indicator contents were 5-6 mg L-1 NO3- and 495-510 mg L-1 AAN in mature leaves, respectively. The optimum N application rate within a season (Nopts) were 240-340 kg N ha-1 (spring) and 130-240 kg N ha-1 (autumn). In summer, shading had strong effects on the Nopty (810 kg N ha-1 a-1 in full sun and 700 kg N ha-1 a-1 under shading) and the critical NO3- levels in young stem (20-33 mg L-1 in full sun and 32-51 mg L-1 under shading). Shading had no effects on the critical soil Nmin and Nopts. The reduced activities of nitrate reductase (NR) under shading might inhibit the synthesis of precursor amino acids of cinnamic acid and the reduced activities of phenylalanine ammonia-lyase (PAL) under shading could inhibit the synthesis of the precursors of catechin. The increased polyphenol oxidase (PPO) under shading enhanced the degradation of polyphenols. The application of K, Mg and S fertilizers could slightly increase the yield and improve the quality in 2003. The activities of NR and PAL were slightly increased by sulphur, but the activity of PPO was inhibited.
J. Li et al., “Exploring the Effects of Magnesium Deficiency on the Quality Constituents of Hydroponic-Cultivated Tea (Camellia Sinensis L.) Leaves,” Journal of Agricultural and Food Chemistry, vol. 69, no. 47, pp. 14278–14286, Dec. 2021.
doi: 10.1021/acs.jafc.1c05141.
Magnesium (Mg) plays important roles in photosynthesis, sucrose partitioning, and biomass allocation in plants. However, the specific mechanisms of tea plant response to Mg deficiency remain unclear. In this study, we investigated the effects of Mg deficiency on the quality constituents of tea leaves. Our results showed that the short-term (7 days) Mg deficiency partially elevated the concentrations of polyphenols, free amino acids, and caffeine but decreased the contents of chlorophyll and Mg. However, long-term (30 days) Mg-deficient tea displayed decreased contents of these constituents. Particularly, Mg deficiency increased the index of catechins’ bitter taste and the ratio of total polyphenols to total free amino acids. Moreover, the transcription of key genes involved in the biosynthesis of flavonoid, caffeine, and theanine was differentially affected by Mg deficiency. Additionally, short-term Mg deficiency induced global transcriptome change in tea leaves, in which a total of 2522 differentially expressed genes were identified involved in secondary metabolism, amino acid metabolism, and chlorophyll metabolism. These results may help to elucidate why short-term Mg deficiency partially improves the quality constituents of tea, while long-term Mg-deficient tea may taste more bitter, more astringent, and less umami.
W. Li et al., “Gibberellin Increases the Bud Yield and Theanine Accumulation in Camellia Sinensis (L.) Kuntze,” Molecules, vol. 26, no. 11, p. 3290, Jan. 2021.
doi: 10.3390/molecules26113290.
Tea (Camellia sinensis) is one of the most important cash crops in the world. Theanine, as an important amino acid component in tea, is a key quality index for excellent tea quality and high economic value. People increase theanine accumulation in tea mainly through the application of nitrogen fertilizer, shading and pruning. However, these methods are not effective. In this study, we treated tea buds with a 100 μM solution of GA3 containing 1‰ tween-20, investigated the effects of GA3 on theanine accumulation, bud yield, chlorophyll fluorescence parameters and expression level of theanine biosynthesis pathway genes in tea plant by qPCR, LC-MS/MS etc. Results showed that change trends of theanine and GA3 was extremely positively correlated with each other. Exogenous GA3 upregulated the expression level of theanine biosynthesis pathway genes, caused an increase of theanine content (mg·g-1) by 27% in tea leaves compared with Mock, and accelerated the germination of buds and elongation of shoots, which lead to a significant increase of tea yield by 56% (w/w). Moreover, the decrease of chlorophyll contents, photochemical quenching coefficient (qP) and relative electron transport rate (rETR) under GA3 treatment suggested that GA3 reduced photosynthesis in the tender tea leaves, indicating that the decline of carbon assimilation in tea plants was conducive to the nitrogen metabolism, and it was beneficial to the accumulation of theanine. This study provided a new technical and theoretical support for the precise control of tea quality components and phenophase.
J. Li et al., “Habitat Management as a Safe and Effective Approach for Improving Yield and Quality of Tea (Camellia Sinensis) Leaves,” Scientific Reports, vol. 9, no. 1, p. 433, Jan. 2019.
doi: 10.1038/s41598-018-36591-x.
Tea (Camellia sinensis) leaves are used to make the most widely consumed beverage globally after water. Therefore, the safety and quality of raw tea leaves are important indices for making tea and related products. Habitat management has been widely used as an environmentally friendly method to control pests in agroecosystems. To investigate the impact of habitat management on tea plantation ecosystems, a habitat management approach with intercropping was established. The function of habitat management on pest control was evaluated. Furthermore, metabolome and transcriptome analysis were applied to assay changes in quality-related metabolites. The habitat management approach was found to maintain arthropod biodiversity and develop natural arthropod enemies in the tea plantation. Therefore, the yield of the habitat management-treated tea plantation was increased. Metabolome analysis showed that epigallocatechin-3-gallate, the major catechin in tea leaves, has a significantly increased content in leaves of tea plants under habitat management compared with those in the control tea plantation. The content of L-theanine, the major amino acid in tea leaves, was not significantly changed in tea plants under habitat management. Furthermore, aroma compounds were more abundant in tea leaves from the habitat management-treated tea plantation than those from the chemical pesticide-treated tea plantation. Therefore, habitat management is reported for the first time as a safe and effective approach to improving the yield and quality of tea leaves.
Y. Liang et al., “Uptake, Accumulation, Translocation, and Subcellular Distribution of Perchlorate in Tea (Camellia Sinensis L.) Plants,” Journal of Agricultural and Food Chemistry, vol. 69, no. 16, pp. 4655–4662, Apr. 2021.
doi: 10.1021/acs.jafc.1c01270.
Perchlorate, emerging pollution with thyroid toxicity, has a high detection rate in fresh tea leaves. What needs attention is that the uptake characteristic is insufficiently understood. Herein, the uptake, accumulation, and translocation of perchlorate in a tea plant–hydroponic solution system were investigated, of which the mechanism was further lucubrated by subcellular distribution. The perchlorate concentration in tea tissues is ramped up along with the increase in the exposure level and time. The bioaccumulation factor of tea tissues followed the rank: mature leaves > tender leaves > roots. After the seedlings have been transplanted to a perchlorate-free solution, the perchlorate in mature leaves is reduced significantly, accompanied by a progressive increase in perchlorate in new shoots and solutions. The cell-soluble fractions are the major reservoir of perchlorate both for roots (>59%) and leaves (>76%), which precisely explained the translocation within the tea plant–hydroponic solution system. These results not only illuminate the uptake characteristic in tea plants but also improve the understanding of the behavior of perchlorate in higher plants.
S. Lin et al., “Soil Acidification Associated with Changes in Inorganic Forms of N Reduces the Yield of Tea (Camellia Sinensis),” Archives of Agronomy and Soil Science, vol. INVALID_SCITE_VALUE, no. INVALID_SCITE_VALUE, pp. 1–14, Aug. 2022.
doi: 10.1080/03650340.2022.2104452.
In this study, 145 tea soils were analyzed and exploredthe relationship between soil pH and soil nitrogen forms and tea yield, which is helpful for more accurate fertilization management, so as to improve tea yield and restore acidified soil. The results showed that 82.1% of the soil samples had a pH < 4.50. Tea yield was positively and significantly (p < 0.01) correlated with soil pH. The dominant N form in tea soils was N(NO3−) in pH 3.00–4.00 and was N(NH4+) in pH 4.50–5.50. With the pH gradient of 3.50–4.50, tea yield was positively significantly (p < 0.01) correlated with soil N(NH4+) content, and was negatively significantly (p < 0.01) correlated with soil N(NO3−) content. These results revealed that soil pH is the determinant factor for soil N forms and tea yield. Soil acidification reduced soil N(NH4+) supply, resulting in the decline of tea yield. We suggested that increasing the soil pH cooperated with input of N(NH4+) fertilizer is primary and foremost for soil pH < 4.5. Increasing N(NH4+) fertilizer thus regulates the ratio of N(NO3–)/N(NH4+) to 1:1 or less is a practical proposal for the soil pH gradient of 4.5–5.5.
S.-K. Lo, C.-Y. Hu, S.-F. Roan, T.-C. Su, and I.-Z. Chen, “Relationship between Flower Phenotypic Traits and Fruit Yields in Tea (Camellia Sinensis L.) Varieties,” Horticulturae, vol. 9, no. 4, p. 440, Apr. 2023.
doi: 10.3390/horticulturae9040440.
In order to provide early selection indicators for the breeding of plants used for producing tea seed oil or harvesting tea, we investigated the relationships between flower morphology and fruit yields in tea plants. We analyzed 106 tea varieties to determine the relationships between flower morphological traits and fruit yields. Notably, the homogeneity of flower traits within the same tea plant variety was found to be very high. The average length and width measurements of certain phenotypic traits of tea plants, including pistil length, stamen length, stamen bundle inner width, stamen bundle outer width, and stigma width, were 11.8, 10.9, 2.5, 15.0, 3.7 mm, respectively. In this study, the flower traits that affect fruit yield appear to be related to the difficulty of pollination by insects (e.g., bees), in terms of their contacting the stigma. In 2013, three phenotypic trait variables showed significant effects on yield; namely, the stamen bundle outer width (negative), stigma width (positive), and stigma width minus the stamen bundle inner width (positive). In 2015, only the stamen bundle outer width had a significant negative effect on yield. Regarding pollen viability, in the TTC (2,3,5-triphenyl tetrazolium chloride) staining test, about 84% of the considered tea varieties presented pollen viability exceeding 70%. This indicates that most tea pollen has the ability to germinate normally after contact with the cross-pollinated stigma. The yields of all of the tea varieties exhibited a positively skewed distribution in 2013 and 2015. Although our results indicate that flowers in the anther superior group tend to produce fewer fruits than flowers in the stigma superior group in 2013, in the analysis of the effect of traits on yield, there were no significant differences in the relative positions of stigmas and anthers. In conclusion, we determined that the main trait affecting fruit yield is stamen bundle outer width, while the secondary trait affecting fruit yield is stigma width. However, the efficacy of the stigma width may also be affected by the position of the stigma relative to the anther and the stamen bundle inner width. These two traits have the potential to be used as reference indicators for early selection in future breeding programs.
L. Long, Y. Shi, L. Ma, and J. Ruan, “Characterization of Young Shoot Population, Yield, and Nitrogen Demands of Tea (Camellia Sinensis L.) Harvested under Different Standards,” Horticulturae, vol. 8, no. 4, p. 275, Apr. 2022.
doi: 10.3390/horticulturae8040275.
The quality of green tea is greatly influenced by the harvest standards for young shoots. The present field experiment was conducted to characterize the young shoot populations, yields, and nitrogen (N) demands of tea plants subjected to four different harvest standards, i.e., buds with one, two, or three young expanding leaves (referred to as B1L, B2L, and B3L, respectively) and a combination of B1L and B3L (B1L/B3L) throughout the year. Weight per shoot was closely related to the number of expanding leaves and was greater in B3L than B1L and B2L, and also greater in summer and autumn than in spring, whereas B1L revealed the greatest young shoot density and highest N concentration. Annual shoot yield and shoot N content were largest in B3L and decreased in the following order: B3L > B2L ≈ B1L/B3L > B1L. However, in the early spring the shoot density, yield, and shoot N content of B1L were much higher than those of B3L. The harvest of B3L significantly reduced the biomass of brown roots and its ratio against the above-ground biomass compared to other harvest standards, suggesting a decreased allocation of carbon to the root system due to seasonal removal. The N dilution curve (Nys = a × Yysb, where Nys is the shoot N content and Yys is the shoot yield) of spring tea differed markedly from those of summer and autumn teas, suggesting different coordination properties for shoot growth and N supply among the seasons. The annual harvest index (NHI) measured by 15N traces ranged between 0.18 and 0.23, indicating relatively low N allocation to young shoots, whereby large proportions (58.2–66.9% of the total 15N absorption) remained in the plant at the end of the experiment. In conclusion, the seasonal distribution of the shoot density, weight per shoot, yield, and N demands vary with harvest standards and highlight the importance of N precision management in tea production to be finely tuned to meet the changes in harvest season and requirements.
G. M. Madamombe, N. J. Taylor, and E. Tesfamariam, “Yield Decline in Vegetatively Propagated Tea (Camellia Sinensis (l.) O. Kuntze) Under Continuous Mechanical Harvesting,” Acta Horticulturae, no. 1007, pp. 857–862, Sep. 2013.
doi: 10.17660/ActaHortic.2013.1007.102.
G. Madamombe, E. Tesfamariam, and N. Taylor, “Yield Decline in Mechanically Harvested Clonal Tea (Camellia Sinensis (L) O. Kuntze) as Influenced by Changes in Source/Sink and Radiation Interception Dynamics in the Canopy,” Scientia Horticulturae, vol. 194, pp. 286–294, Oct. 2015.
doi: 10.1016/j.scienta.2015.08.009.
High labour costs and shortages and the cost of production has resulted in tea (Camellia sinensis (L) O. Kuntze) industries in central and southern Africa becoming unprofitable. This has led to the full mechanization of shoot harvesting, however, a reduction in yield has been observed with mechanical harvesting. It was hypothesized that the decline in yield as a result of mechanical harvesting is a result of the indiscriminate harvesting of shoots which leads to a change in sink/source and radiation interception dynamics within the canopy. As a result whole plant photosynthesis is impacted; which ultimately impacts tea bush productivity. Studies conducted at Tingamira estate, Chipinge, Zimbabwe showed significant yield differences between hand plucking and machine harvesting treatments, with higher yields under hand plucking across all seasons (43945kggreen leafha−1) as compared to hand-held (35114kggreen leafha−1) and ride-on machines (36268kg green leafha−1) (p<0.05). This reduction in yield was associated with a decrease in both the number and mass of desirable shoots over each season. The cause of this change was largely attributed to the indiscriminate removal of foliage by the machines which resulted in the proliferation of immature shoots, with an associated increase in sink strength and competition for available photo-assimilates. In addition, the depletion of the maintenance layer in mechanically harvested bushes, as indicated by reduced fractional interception of photosynthetically active radiation in the top 10cm in these bushes and reduced photosynthetic rates in these bushes, suggests that these bushes were also source limited, as compared to hand plucked bushes. Therefore the changes in tea bush architecture, as a result of mechanical harvesting, resulted in changes in sink/source dynamics which led to a proliferation of immature shoots which competed for limited photo-assimilates.
M. J. S. Magambo and K. Waithaka, “The Effect of Pruning at Different Heights on Yields, Dry Matter Production and Partitioning in Clonal Tea (Camellia Sinensis) in Kenya,” Experimental Agriculture, vol. 21, no. 1, pp. 67–72, Jan. 1985.
doi: 10.1017/S0014479700012266.
Dry matter production and partitioning in old clonal tea bushes pruned and maintained at different heights were investigated. New tissues (leaves, new branches and small roots) consti- tuted a small fraction of the total dry matter in all bushes pruned and initially maintained at 70, 40, 25 and 10 cm high, 36 months after pruning. Leaf/frame dry matter ratio was larger and the shoot/root and frame/root ratios were smaller in the bushes initially maintained at 10 cm than in the bushes maintained at other heights. Yields per unit area of the plucking surface were greatest in the smallest bushes initially maintained at 10 cm in 42 months of recording but on the basis of the available space they were greatest in the large bushes initially maintained at 70 cm.
M. P. Malebe, R. K. Koech, E. G. N. Mbanjo, S. M. Kamunya, A. A. Myburg, and Z. Apostolides, “Construction of a DArT-Seq Marker–Based Genetic Linkage Map and Identification of QTLs for Yield in Tea (Camellia Sinensis (L.) O. Kuntze),” Tree Genetics & Genomes, vol. 17, no. 1, p. 9, Jan. 2021.
doi: 10.1007/s11295-021-01491-1.
As the second most consumed non-alcoholic beverage, the tea plant (Camellia sinensis) has high economic value. Tea improvement efforts that largely target economic traits such as yield have traditionally relied on conventional breeding approaches. The tea plant’s perennial nature and its long generation time make conventional approaches time-consuming and labour-intensive. Biotechnology provides a complementary tool for accelerating tea improvement programmes through marker-assisted selection (MAS). Quantitative trait loci (QTLs) identified on linkage maps are an essential prerequisite to the implementation of MAS. QTL analysis was performed on yield data over 3 years (2010–2012) across two sites (Timbilil and Kangaita, in Kenya), based on two parental framework linkage maps arising from a population of 261 F1 progeny, derived from a reciprocal cross between GW Ejulu and TRFK 303/577. The maps contain 15 linkage groups each, this corresponds to the haploid chromosome number of tea (2n=2x=30). The total length of the parental maps was 1028.1 cM for GW Ejulu and 1026.6 cM for TRFK 303/577 with an average locus spacing of 5.5 cM and 5.4 cM, respectively. A total of 13 QTLs were identified over the three measurement years. The 13 QTLs had LOD values ranging from 1.98 to 7.24 and explained 3.4% to 12% of the phenotypic variation. The two sites had seven mutually detected QTLs.
L. S. Malyukova et al., “Effects of Calcium-Containing Natural Fertilizer on Camellia Sinensis (L.) Kuntze,” Bangladesh Journal of Botany, vol. 50, no. 1, pp. 179–187, Mar. 2021.
doi: 10.3329/bjb.v50i1.52686.
The effects of application of calcium-containing natural fertilizer on the functional state of the tea plant were studied. Application of calcium resulted weakening of the negative effects of high temperatures and water deficiency due to an increase in its heat resistance (on average by 30 - 40%), an increase in catalase activity (on average 5 - 10 %), as well as adaptive rearrangement of pigment ratio to increasing the content of carotenoids, chlorophylls and the their functional activity. In general, the more efficient functioning of the signaling intracellular network due to the calcium application provided better adaptability of plants to extreme conditions and more efficient recovery after subsequent rehydration, which in a whole contributed to an increase in shoot growth activity (on average 20%) and an increase in yield by an average of 27 - 33%.
N. Mokaya, “Effect of Varying Rates of Organic and Inorganic Fertilizers on Growth, Yield and Nutrient Use Efficiency of Clonal Tea (Camellia Sinensis L. [o] Kuntze),” Thesis, University of Nairobi, 2016.http://erepository.uonbi.ac.ke/handle/11295/98483.
Small scale tea farmers apply inorganic NPK fertilizers annually in a bid to increase tea yields but the cost of fertilizers has been increasing leading to the reduction in the net returns. A study was conducted to determine the effect of varying rates of organic and inorganic fertilizers on the soil chemical properties, growth, yield and nutrient use efficiencies of clonal tea. Experiments were set up at Kianjokoma in Embu County in 2014/2015 production year. The fertilizers used were organic Rutuba® and inorganic NPK (26.5.5). The treatments comprised: no-fertilizer control, 625 kg NPK/ha, 937.5 kg NPK/ha, 1875 kg NPK/ha, 625 kg Rutuba/ha + 625 kg NPK /ha, 625 kg Rutuba/ha, 937.5 kg Rutuba/ha and 1875 kg Rutuba/ha. These treatments were laid out in a randomized complete block design and replicated three times. Crop data collected comprised green leaf yield, black made tea yield, leaf length and leaf width. Soils data collected at the end of the experiment included pH, exchangeable acidity, organic carbon, micronutrients and macronutrients. Nitrogen, phosphorus and potassium plant use efficiencies were also determined. The cost and net revenue for each of the fertilizer treatments were also calculated. Data were subjected to analysis of variance and mean separation was done using the least significant difference test at p ≤0.05. The use of organic Rutuba increased the soil pH, Mn, Cu, Fe, Zn, Ca and Mg levels. Application of 625 kg Rutuba/ha + 625 kg NPK/ha resulted to increased leaf length, leaf width, fresh green leaf yield and made tea yield relative to the nofertilizer control and the farmers’ practice. The results indicated that the agronomic efficiency, apparent nutrient recovery and partial factor productivity of N, P and K were significantly enhanced by the application of Rutuba fertilizer relative to inorganic NPK fertilizer. The study further demonstrated that use of NPK 26.5.5 rates of more than 625 kg/ha did not increase growth, yield, nutrient use efficiencies and net returns. However, the study concluded that organic Rutuba may not be used singly in tea production as it has low levels of macronutrients. Further trials to determine the optimal NPK and Rutuba fertilizers combination as well as the effect of organic Rutuba fertilizer on the quality of tea are recommended.
A. Morita, R. Suzuki, and H. Yokota, “Effect of Ammonium Application on the Oxalate Content of Tea Plants (Camellia Sinensis L.),” Soil Science and Plant Nutrition, vol. 50, no. 5, pp. 763–769, Feb. 2004.
doi: 10.1080/00380768.2004.10408533.
Tea plants (Camellia sinensis L.) were hydroponically cultured for 9 d in a solution containing ammonium as a sole nitrogen source (0 (control), 50, 100, or 200 mg N L-1 ), and harvested after 0 (control), 1,3,6, and 9 d of treatments to investigate the effect of ammonium on the content and metabolism of oxalate in tea plants. Total and water-soluble oxalate contents in young leaves and roots treated with 50, 100, and 200 mg N L-1 decreased in proportion to the amount of ammonium applied, with levels significantly lower than those without ammonium application. In old leaves, both total and water-soluble oxalate contents showed constant values during the treatment period. The content of total ascorbic acid (AsA) in young leaves increased with the amount of ammonium in the medium. The activity of oxalate oxidase (OxO) in young leaves also increased with the concentration of ammonium in the medium and with the duration of the treatment. However, in roots, total AsA content and OxO activity were not affected. These results suggest that in young tea leaves, the application of ammonium suppressed the synthesis of oxalate via AsA oxidation and stimulated the decomposition of oxalate by the increase of the OxO activity, resulting in the accumulation of AsA and a decrease in oxalate content. On the other hand, in old leaves and young roots, the responses to ammonium were different from those in young leaves, suggesting that the oxalate metabolism may be controlled by different mechanisms in different parts of the tea plants.
A. Morita, M. Ohta, and T. Yoneyama, “Uptake, Transport and Assimilation of 15N-Nitrate and 15N-Ammonium in Tea (Camellia Sinensis L.) Plants,” Soil Science and Plant Nutrition, vol. 44, no. 4, pp. 647–654, Dec. 1998.
doi: 10.1080/00380768.1998.10414488.
15N studies were conducted using hydroponically grown tea (Camellia sinensis L.) plants to clarify the characteristics of uptake, transport and assimilation of nitrate and ammonium. From the culture solution containing 50 mg L-1 N03-N and 50 mg L-1 NH.-N, the uptake of NH3-N after 24 h was twice as high as that of NO3-N, while the uptake of N03-N from the culture solution containing 90 mg N03-N and 10 mg NH3-N was twice that of NH4-N. The presence of 0.4 mM Al had no significant effect on the N03-N and NH4-N uptake from the culture solutions containing 50 mg L-1 N03-N and 50 mg L-1 NH4-N, 90 mg L-1 N03-N and 10 mg L-1 NH4-N or 99 mg L-1 N03-N and 1 mg L-1 NH4-N. Transport of N03-derived N to young leaves was much more rapid than that of NH4-derived NO3 and NH4-derived N was largely retained in the roots and lower stem. Young and mature shoots separated from the roots absorbed more N03-N than intact plants. Nitrate assimilation occurred in both, roots and young as well as mature leaves. Internal cycling of N03-derived Nand NH4-derived N from one root part to another part was not appreciable after 28 h, suggesting that a longer of time is required for cycling in woody plants.
R. C. Muoki, A. Paul, A. Kumari, K. Singh, and S. Kumar, “An Improved Protocol for the Isolation of RNA from Roots of Tea (Camellia Sinensis (L.) O. Kuntze),” Molecular Biotechnology, vol. 52, no. 1, pp. 82–88, Sep. 2012.
doi: 10.1007/s12033-011-9476-5.
Tea, a beverage crop, is a rich source of polyphenols and polysaccharides which greatly attribute to its importance. However, oxidation and precipitation of these compounds during nucleic acids extraction is a limitation to molecular biology and genomic studies. On isolation of total RNA from root tissue using established protocols, difficulties were encountered in terms of purity and quantity of isolated RNA or some of the methods were time-consuming and also yields were low. The present communication combines a phenol-based RNA isolation protocol with a cetyltrimethylammonium bromide-based procedure with appropriate modifications. This protocol successfully isolated RNA from tap root tissue in 2–3 h as compared with 16 h reported by the previous method. Also, RNA yield was higher by more than fourfold. The RNA isolated by this protocol was successfully used for downstream applications such as RT-PCR and the construction of suppression subtractive hybridization library. The developed protocol worked well with other plant tissue with high polyphenols and polysaccharides contents.
C. Njoloma, “Application of Foliar Sprays Containing Copper, Zinc and Boron to Mature Clonal Tea (Camellia Sinensis) : Effect on Yield and Quality,” PhD thesis, University of Pretoria, 2012.https://repository.up.ac.za/handle/2263/24956.
Most of the fields planted with clonal tea in Malawi are deficient in micronutrients. This was evident in leaf analysis data collected in 2007 from 170 mature clonal tea fields of some of the tea estates in Malawi, which showed very high incidences of B, Zn and Cu deficiencies. Current fertiliser recommendations have emphasised much on macronutrients, such as N, Pand K, but little attention has been paid to micronutrient elements despite continuous removal through harvesting. A study was therefore conducted to assess the effect of foliar applications of Cu, Zn and B containing fertilisers on yield and quality of mature clonal tea plants. Field experiments were laid out in randomised blocks in two fields planted with cultivars PC 105 and 108 at Mianga and Glenorchy estates in the Mulanje district in Malawi and were replicated four times at each site. The treatments were T1 (control, no spray), T2 [ 0.1% boric acid (190.8g B/ha)], T3 [1% copper sulphate solution (4.35kg Cu/ha)], T4 [1.25kg/ha zinc oxide (1kg Zn /ha)], T5 [0.1% boric acid, 1% copper sulphate solution, 1.25kg/ha zinc oxide], T6 [1% of Commercial micronutrient mix ( N 1.7%, P 2.3%, K 1.6%, Mg 0.25%, Fe 1288 mg/kg, Mn 1005 mg/kg, Zn 2182 mg/kg, Cu 732 mg /kg, B 8202 mg/kg, Mo 3681 mg/kg, kelp extract 75 mg/kg, amino acids 50 g/kg, phytofulvate 50 g/kg)], and T7 [2.48kg/ha zinc sulphate (1kg Zn /ha)]. Micronutrient foliar sprays affected yield significantly at Glenorchy tea estate, but had no significant effect on yield at Mianga estate. Copper sulphate solution applied at 1% concentration decreased yield, but the other foliar applications did not impact yield relative to the control at Glenorchy. Tea quality by taster’s scores was not affected at Mianga estate, whilst at Glenorchy quality was affected, with the commercial micronutrient mix giving the lowest total score. Individual parameters that contributed to the differences in total scores at Glenorchy estate included brightness, briskness, colour of liquor, colour of infusion and colour with milk. Thearubigin (TR) concentration was the only biochemical quality parameter that was affected by the micronutrient foliar sprays. The level of TR was increased in all treatments that received the foliar sprays and the control treatment gave the lowest amount of TRs at both sites. An increase in the Thearubigin/Theaflavin (TR/TF) ratio, obtained in all treatments that received the foliar sprays, provides evidence that more catechins were being converted to TRs than TFs during fermentation. Foliar levels of B, Zn and Cu were raised significantly by the application of the respective foliar sprays, except for the commercial micronutrient mix which did not significantly increase B and Zn levels at both sites, but raised Cu levels to the recommended level only at Mianga, but not at Glenorchy estate. Concentration of Cu was extremely high in tea leaves treated with copper sulphate either alone or in combination with boric acid and zinc oxide. Levels of other nutrient elements, namely N, P, K, S, Zn, Cu, Mg, Mn, Mo, Ca, Fe, B, Al and Na in the soils where different foliar sprays were applied were similar at both sites. Likewise, foliar levels of N, P, K, S, Zn, Cu, Mg, Mn, Mo, Ca, Fe, B, Al and Na were not different in all plots at Mianga, but at Glenorchy differences in foliar levels of Al and S were noted. High concentrations of Al and S in the leaves were observed in plots that received copper sulphate applied alone. High foliar concentrations of Al and Cu in leaves treated with copper sulphate could be the reason for the low yields obtained in the plots treated only with copper sulphate at Glenorchy estate. Foliar application of Cu, Zn and B in forms of 0.1% boric acid (190.8g B/ha)], 1% copper sulphate solution (4.35kg Cu/ha)], [1.25kg/ha zinc oxide (1kg Zn /ha)], 1% of a Commercial micronutrient mix (N 1.7%, P 2.3%, K 1.6%, Mg 0.25%, Fe 1288 mg/kg, Mn 1005 mg/kg, Zn 2182 mg/kg, Cu 732 mg /kg, B 8202 mg/kg, Mo 3681 mg/kg, kelp extract 75 mg/kg, amino acids 50 g/kg, phytofulvate 50 g/kg), and 2.48kg/ha zincsulphate (1kg Zn /ha) to mature clonal tea did not significantly increase yields and tea tasters scores, therefore their application to clonal tea with the aim of improving yield and quality may not be necessary. Results from this study indicated that clonal tea, specifically cultivars (PC 108 and PC 105), could not give positive results in terms of yield and quality of tea due to foliar application of Cu, Zn and B within the first season of application. However, if application is aimed at raising concentrations of Cu, Zn, and B, then boric acid, zinc sulphate, zinc oxide and the commercial micronutrient mix may be used without negatively affecting yield and quality of tea significantly. Copper sulphate however, at the application concentration and frequency used, should not be done because of the observed yield decline in copper sulphate treated plots. More prolonged research is required to determine if long term applications can correct perceived deficiencies and increase yield.
“Journal Crop and Weed_11_Special Issue_2015.”
An investigation was conducted at DTRDC experimental farm (mid elevation) and Sungma Tea Estate (High elevation), Darjeeling during 2012 to 2013 to study the effect of photosynthetic activities on Darjeeling tea clonal cultivars of hybrids’ China’- type and old china tea bush. Net photosynthetic rate (Pn) of clone T78, AV2, B157 and Old china cultivation was 11.23, 11.07, 10.26 and 9.63 µ molm-2s-1 at mid elevation (DTRDC, experimental farm) and clone T78, AV2, B157 and Old china cultivation was 10.57, 10.13, 9.41 and 8.41 µ molm-2s-1 respectively at high elevation from the top of canopy (0- 10 cm). Among the clones, T78 and B157 showed lower rate of transpiration (E) than clone, AV2 and old china cultivation at both elevation of Darjeeling hill. Water use efficiency (WUE) of clone T78 was higher as compared to clone, B157, AV2 and old china cultivation. Among the clones, AV2 and Old china bush showed lower rate of leaf water potential (øL) than clone, T78 and B157 at both elevation of Darjeeling hill. Maximum Leaf area Index (LAI) was recorded in from the mid elevation than high elevation in the canopy depth 0-10cm. Clone AV2 was recorded lowest leaf area index in mid elevation than high elevation. Leaf area index (LAI) has a positive correlation with yield. In all treatments, vapour pressure deficit (VPD) was highest in the canopy depth 0-10cm. Highest annual tea yield was 729.26 Kg ha-1 recorded in T78 clone at mid elevation than high elevation and varied with clone.
K. W. Nyabundi, P. O. Owuor, G. W. Netondo, and J. K. Bore, “Genotype and Environment Interactions of Yields and Yield Components of Tea (Camellia Sinensis) Cultivars in Kenya,” 2016.https://repository.maseno.ac.ke/handle/123456789/291.
The tea crop provides income and employment to rural populations in many countries. In Kenya, tea, which is the leading export commodity crop, is grown in highlands east and west of the Rift Valley at altitudes ranging from 1300 m to 2700 m above mean sea level. Variable responses of tea genotypes to different environments have been demonstrated. This affects the growth, productivity, and quality of tea. However, most tea husbandry practices are uniform across tea growing regions leading to variations in yields and quality in the different environments. Understanding causes of variations in tea growth parameters and yields to varying environments is vital to optimizing husbandry practices for maximization of productivity. The responses in growth and yield parameters of clonal tea to locations of production and their contribution to yields were compared. A genotype× …
K. W. Nyabundi, P. O. Owuor, G. W. Netondo., and J. K. Bore, “Seasonal and Environment Variations of Yields and Yield Components of Tea (Camellia Sinensis) Cultivars in Kenya,” 2017.https://repository.maseno.ac.ke/handle/123456789/654.
In Kenya, tea is grown in highlands east and west of the Rift Valley at altitudes ranging from 1300 m to 2700 m above mean sea level. These areas vary widely in seasonal and locational environmental factors leading to differences in responses in growth, productivity and quality of tea genotypes. Despite these differences, tea husbandry practices are uniform across tea growing regions in the country. Understanding modes of variations in tea growth parameters and yields to varying environments is crucial for optimization of husbandry practices for tea productivity improvements. Responses in clonal tea growth and yield parameters to season and locations of production effects and their contribution to yields were evaluated, using 20 cultivars in a genotype × environment trial conducted in three locations (Kipkebe, Timbilil and Kangaita). There were yield variations (pd”0.05) between clones, locations and seasons. Tea yield components responses to weather parameters varied with location and season. Shoot growth rates in Kangaita and shoot density in Timbilil linearly correlated (pd”0.05) with yields but varied with season. Yield components and weather parameters contribution to the yield also varied with location and seasons causing significant (pd”0.05) interactions effects. Drought reduced yields while rainfall distribution influenced seasonal yield distribution. Seasonal yield variations were due to shoot growth rate, and shoot dry weight changes but not shoot density. The variations were due to seasonal environmental factors that limited yields rather than factors that increased yields.
H. E. Nyirenda and V. E. T. Ridpath, “Criteria for Clonal Selection in Tea (Camellia Sinensis). I. The Relation Between Mother Bushes and Their Clonal Derivatives for Bush Area, Shoot Number and Yield,” Experimental Agriculture, vol. 20, no. 4, pp. 339–343, Oct. 1984.
doi: 10.1017/S0014479700018032.
Bush area, shoot number and yield were all strongly and positively correlated in 100 young seedling tea bushes. Clones derived from the bushes exhibited characteristics which were correlated with those of the mother bushes, indicating the usefulness of these observations in the selection of clones for improved performance.
H. E. Nyirenda and C. W. Kayange, “Effect of Rootstocks on Components of Yield in Tea (Camellia Sinensis (L.) O. Kuntze). 2. Stem Circumference and Number of Branches,” Journal of Horticultural Science, vol. 59, no. 4, pp. 589–594, Jan. 1984.
doi: 10.1080/00221589.1984.11515237.
Stem size expressed as circumference at ground level, the number of branches arising from the main stem, total branches at pruning level and yields were determined in three- year-old chip-budded and own-rooted plants. Both rootstocks and scions had a marked influence on stem thickness, branching and yield potential of the composite plants. High-yielding scions produced plants with thicker stems than the control only on very vigorous rootstocks whereas weak rootstocks exerted negative effects on plant growth. Average-yielding scions benefited from all rootstocks though more from vigorous than from weak ones. Strong interrelationships existed between stem circumference, number of branches and yield.
H. E. Nyirenda, “Effectiveness of Assessment of Vigour and Productivity in Young vs Old Bushes and Mature Clones of Tea (Camellia Sinensis),” Annals of Applied Biology, vol. 115, no. 2, pp. 327–332, 1989.
doi: 10.1111/j.1744-7348.1989.tb03391.x.
The effectiveness and validity of assessment of bush vigour as expressed by bush area, shoot number and yield in selecting for high yielding clones in tea was tested by comparing the field performance of 50 source bushes when they were 4 yr old in 1977/78 with that of the same bushes when they were 13 yr old in 1986/87 and also with that of the 8 yr old vegetatively propagated plants (clones) derived from them and transplanted to the field in December 1979. Apparently vigorous bushes produced the highest yield. The three characters measured in mature source bushes and, to a lesser extent, clonal derivatives were positively correlated with measurements in young source bushes. Seven of the best yielding source bushes and five of the best clones in 1986/87 were present in the 10 highest yielding source bushes identified in the 1977/78 season. Assessment of bush area and shoot number was confirmed as an effective and valid method of identifying a small, highest yielding group of source bushes from a large population of seedling tea which should go for rooting assessment and further more thorough screening of yield.
H. E. Nyirenda, “Use of Growth Measurements and Foliar Nutrient Content as Criteria for Clonal Selection in Tea (Camellia Sinensis),” Experimental Agriculture, vol. 27, no. 1, pp. 47–52, Jan. 1991.
doi: 10.1017/S0014479700019190.
A selection programme conducted on young clonal tea plants grown in large sleeved bags and in a field trial established criteria for selecting high yielding field clones on the basis of their growth in early years. Bush area, number of branches and shoots per bush, and foliar phosphorus content at the second crop peak were correlated with yield but the correlation between stem circumference at ground level and yield was inconsistent. It is therefore concluded that all these bush and growth characters, apart from stem circumference, may be reliably used to predict and select high yielding tea clones.
P. O. Owuor, C. O. Othieno, H. O. Odhiambo, and W. K. Ng’etich, “Effect of Fertilizer Levels and Plucking Intervals on Yield and Quality of Clonal Tea [Camellia Sinensis (L.) Kuntze],” Tropical Agriculture, 1997.https://journals.sta.uwi.edu/ojs/index.php/ta/article/view/2504.
Variation in yield and black tea (Camellia sinensis (L.) Kuntze) quality of a high-yielding clone, S 15/10 in response to rates of NPKS 25:5:5:5 (at 100-600 kg N ha-1 yr-1) fertilizer and three plucking intervals (7, 14, and 21 days) were studied. Yields responses were quadratic, reaching calculated maximum production when 466, 487, and 491 kg N ha-1 yr-1 was applied at 7, 14, and 21 days plucking intervals, respectively. But significant yield increase was achieved by applying only up to 200 kg N ha-1 yr-1.The most profitable production was also achieved by applying 200 kg N ha-1 yr-1 irrespective of plucking intervals, at the 1993 production costs in Kenya. Mean weights of plucked (two leaves and a bud) shoots, shoot density, and shoot extension rate increased with fertilizer rates. On unselective plucking, long plucking intervals produced leaf with a high proportion of mature (coarse) leaf beyond two leaves and a bud.
P. O. Owuor and B. O. Kwach, “Quality and Yields of Black Tea Camellia Sinensis L. O. Kuntze in Responses to Harvesting in Kenya: A Review.,” Asian Journal of Biological and Life Sciences, vol. 1, no. 1, pp. 1–7, 2012.https://www.cabdirect.org/cabdirect/abstract/20133360050.
Tea beverages, from tender shoots of Camellia sinensis L., are the most widely consumed fluids after water. The young tender shoots of the plant are harvested using various plucking methods. Incorrect plucking leads to yield and quality declines. It is therefore necessary that this process is optimised. Extensive research showed changes in the chemical composition, quality and yields of black tea...
P. O. Owuor and H. O. Odhiambo, “The Response of Quality and Yield of Black Tea of Twocamellia Sinensis Varieties to Methods and Intervals of Harvesting,” Journal of the Science of Food and Agriculture, vol. 62, no. 4, pp. 337–343, 1993.
doi: 10.1002/jsfa.2740620405.
The sensory evaluation and chemical quality parameters of black teas changed with variety, plucking round length and method of plucking. Hand plucked teas had higher theaflavins (TF), caffeine, brightness, flavour index. Group II volatile flavour compounds (VFC) and sensory evaluations, but lower Group I VFC than shear plucked teas irrespective of variety. Black teas plucked from short plucking rounds were superior to those from long plucking rounds as assessed by TF, caffeine, brightness, the chemical aroma quality parameters and sensory evaluation. Long plucking intervals and shear plucking reduced tea yields and produced coarser leaf than short plucking intervals and hand plucking respectively.
R. K. Panda, W. Stephens, and R. Matthews, “Modelling the Influence of Irrigation on the Potential Yield of Tea (Camellia Sinensis) in North-East India,” Experimental Agriculture, vol. 39, no. 2, pp. 181–198, Apr. 2003.
doi: 10.1017/S0014479702001151.
This study reports the results of model simulations of the potential yield of tea in north-east India. The CUPPA-Tea model, developed using data from a high-altitude site close to the equator in East Africa, was validated against the yield data from irrigation experiments conducted on contrasting soil types at Siliguri and Tezpur in the tea growing region of north-east India. The close correspondence between observed and predicted yield and yield distribution suggests that the model is applicable in north-east India. The model was used to simulate the yield response of tea to drought and irrigation using daily weather data for seven years (1983–89) at Siliguri and 14 years (1974–85) at Tezpur. On a clay loam soil at Siliguri, with an available water capacity of about 200 mm m−1, the predicted mean reduction in yield was 1.5 kg ha−1 for each 1 mm reduction in evapotranspiration. However, there appeared to be no reduction in evapotranspiration until the soil water deficit reached about 240 mm. By contrast, at Tezpur on loamy sand, with an available water capacity of about 100 mm m−1, evapotranspiration was reduced once soil water deficits exceeded about 85 mm. There was then a mean reduction in yield of 2.2 kg ha−1 for each 1 mm reduction in evapotranspiration. At both sites, even when soil water deficits were not limiting, the predicted year-to-year variation in yields was about 500 kg ha−1. The results highlight the soil-related differences in response to irrigation and the benefits of using process-based simulation models to investigate the potential yields over long periods.
R. L. Pastore and P. Fratellone, “Potential Health Benefits of Green Tea (Camellia Sinensis): A Narrative Review,” EXPLORE, vol. 2, no. 6, pp. 531–539, Nov. 2006.
doi: 10.1016/j.explore.2006.08.008.
P. Patel, B. Das, R. Sarma, and B. Gogoi, “Tea Seed: A Review,” Annual Research & Review in Biology, vol. 25, pp. 1–14, Mar. 2018.
doi: 10.9734/ARRB/2018/40418.
A. Perva-Uzunalić, M. Škerget, Ž. Knez, B. Weinreich, F. Otto, and S. Grüner, “Extraction of Active Ingredients from Green Tea (Camellia Sinensis): Extraction Efficiency of Major Catechins and Caffeine,” Food Chemistry, vol. 96, no. 4, pp. 597–605, Jun. 2006.
doi: 10.1016/j.foodchem.2005.03.015.
The effect of different extraction set-ups that influence the extraction efficiency of catechins and caffeine from green tea leaves (variety Fanning Belas, China) were studied using different aqueous and pure solvents (acetone, ethanol, methanol, acetonitrile, water), different temperatures (60, 80, 95 and 100°C) and times (5–240min). Raw extracts were analysed for contents of major catechins (EC, EGC, ECG, EGCG), caffeine, proanthocyanidins and flavonols (myricetin, caempherol, quercetin). Starting material was found to contain 191g major catechins/kg material, 36g caffeine/kg material and 5.2g flavonols/kg material on a dry mass basis. The content of major catechins in green tea extracts varied from approximately 280–580g/kg dry extract, with extraction efficiencies of major catechins varying from 61% to almost 100%. Content of caffeine in extract was in the range of 75g/kg, where its extraction efficiency varied from 62% to 76%. Average extraction yield was 30% with exceptions when using pure acetone and acetonitrile, where extraction yield was about 3%. Contents of flavonols and proanthocyanidins were in the ranges 6–20 and 12–19g/kg, respectively. Different extraction procedures with water were also investigated and optimal conditions determined: maximum achieved extraction efficiency of catechins with water was obtained at 80°C after 20min (97%) and at 95°C after 10min of extraction (90%). Degradation of catechins was observed at higher extraction temperatures and with prolonged extraction times. Using a lower ratio of solvent to material, extraction efficiencies were increased by applying a multi-step extraction procedure. Optimal extraction procedure was then performed using decaffeinated green tea leaves, which were obtained by high-pressure extraction with CO2, when 98% of caffeine was selectively isolated without significant impact on valuable catechins.
P. Pongrac et al., “Contrasting Allocation of Magnesium, Calcium and Manganese in Leaves of Tea (Camellia Sinensis (L.) Kuntze) Plants May Explain Their Different Extraction Efficiency into Tea,” Food and Chemical Toxicology, vol. 135, p. 110974, Jan. 2020.
doi: 10.1016/j.fct.2019.110974.
During tea preparation mineral elements are extracted from the dried leaves of tea (Camellia sinensis (L.) Kuntze) plants into the solution. Micro-particle induced X-ray emission was employed to investigate the spatial distribution of magnesium (Mg), calcium (Ca) and manganese (Mn) in the young and old leaves of tea plants grown in the absence and presence of aluminium (Al) in the substrate. Results revealed that in tea leaves the largest concentrations of Mg occurred in the epidermis, of Ca in oxalate crystals and of Mn in epidermis and oxalate crystals; there was a leaf-age effect on tissue-specific concentrations of Mg, Ca and Mn with all tissues of old leaves containing larger concentrations of Mg, Ca and Mn than young leaves; supplementation of substrate with Al reduced concentrations of Mg, Ca and Mn in the old leaves, and a link between the distribution of Mg, Ca and Mn in the tea leaves with the extraction efficiencies of these elements into the tea was possible. We conclude that old leaves of tea plants cultivated under conditions of low Al availability will have the largest concentrations of Mg, Ca and Mn and may represent most acceptable ingredient for the preparation of tea.
P. A. Pool and H. E. Nyirenda, “Effects of Rootstocks on the Components of Yield in Tea (Camellia Sinensis L.),” Journal of Horticultural Science, vol. 56, no. 2, pp. 121–123, Jan. 1981.
doi: 10.1080/00221589.1981.11514976.
Two vigorous, low-quality rootstocks increased the yield of a high-quality, low-yielding clone (SFS 204) by about 38%-42%, largely owing to an increase in the number of shoots produced by this clone. The yield of clone PC I, which normally produced more shoots than SFS 204, was increased by 25%-31%, again largely owing to an increase in shoot number. Rootstocks had relatively little effect on mean weight per shoot or on shoot growth rates.
A North Carolina Design II experiment was used to examine the genetic variability of yield, quality and some associated characters in tea (Camellia sinensis L.). Considerable variation was apparent for all parameters studied. Differences between progenies were attributable to general combining ability, rather than specific combining ability, for most of the characters. Relatively low narrow sense heritabilities were obtained for both yield and quality. Correlation coefficients, which were computed for all combinations of variates, showed that yield and quality were inversely related, and indicated that shoot density was the single most important factor governing yield. Principal component analysis was used in order to elucidate further this complex of relationships. It is suggested that bushes with an upright growth habit, a large number of shoots per unit area and a high rate of shoot extension will represent high yielding genotypes. Implications for breeding and selection are discussed.
S. Raguraj et al., “Urea–Hydroxyapatite Nanohybrid as an Efficient Nutrient Source in Camellia Sinensis (L.) Kuntze (Tea),” Journal of Plant Nutrition, vol. 43, no. 15, pp. 2383–2394, Sep. 2020.
doi: 10.1080/01904167.2020.1771576.
Slow-release fertilizers based on nanomaterials have recently proven promise in increasing nitrogen use efficiency by plants and reduction in environmental hazards. We have previously reported the synthesis of an efficient and novel plant nutrient formulation based on urea–hydroxyapatite (HA) nanohybrid and its efficacy at small scale field trials conducted using rice as the model crop. This work focuses on a study of the effect of urea–HA nanohybrid fertilizer on the yield and quality of tea in farmer’s fields selected from three climatic zones (Low Country, Mid Country, and UVA regions) in Sri Lanka for a period of three years. Experiments were carried out using treatments with half and full amounts of nitrogen recommendations to the tea plant, supplied through both conventional urea and nanohybrids at two and four splits per annum. Annual N requirement supplied through nanohybrids in Low Country and Uva showed a yield increment of 10–17% and 14–16%, respectively, compared with conventional recommendation. Nanohybrid fertilizer also allowed to reduce the number of fertilizer applications and the amount used by 50% resulting in matching yields to the conventional fertilizer applications. However, only a minute yield increase of 2–3% was observed in mid Country. Yield component analysis carried out in the Uva region was evident for increased tea yield obtained by application of slow-release nanofertilizer. Moreover, application of slow-release fertilizer significantly increased soil P, leaf N, and P concentration in Low Country tea yields. A positive effect of HA–urea nanohybrids was more pronounced during unfavorable climatic conditions.
C. S. V. Ram, “Foliar Application of Nutrients and Rhizosphere Microflora of Camellia Sinensis,” Nature, vol. 187, no. 4737, pp. 621–622, Aug. 1960.
doi: 10.1038/187621a0.
SUSCEPTIBILITY of plants to fungi causing root-rot is known to be conditioned by the rhizosphere microflora1,2. Changes in this microflora can result from derangement in plant metabolism caused by either foliar treatment with chemicals3, fungal infection of the roots2 or even systemic infection by plant viruses4. Therefore, it seems possible to stimulate artificially the multiplication of specific micro-organisms in the rhizosphere by selective plant treatment, such as foliar application of nutrients, designed to act directly on the plant without affecting the soil. Work on these lines, apart from a recent report5, has received little attention. Observations on sprayed tea plants reported here support the basic concept of changing the pattern of the rhizosphere microflora by foliar sprays.
A. Rani, K. Singh, P. Sood, S. Kumar, and P. S. Ahuja, “P-Coumarate:CoA Ligase as a Key Gene in the Yield of Catechins in Tea [Camellia Sinensis (L.) O. Kuntze],” Functional & Integrative Genomics, vol. 9, no. 2, pp. 271–275, May 2009.
doi: 10.1007/s10142-008-0098-3.
Tea is an important crop known for its beverage and antioxidant polyphenols—catechins and its derivatives. Catechins are synthesized through flavonoid (FL) pathway and stored in the vacuole. A metabolic flux for the operation of FL pathway is maintained through the supply of 4-coumaroyl-CoA of phenylpropanoid pathway. 4-Coumaroyl-CoA is synthesized through the catalytic activity of p-coumarate:CoA ligase (4CL) using 4-coumaric acid and acetyl-CoA as the substrates. The present manuscript reports the full-length cDNA cloning of 4CL from tea (Cs4CL accession number DQ194356) and its association with catechin yield. Cs4CL comprised of 2,165 bp with an open reading frame (ORF) of 1,764 nt, starting from 118 to 1,882 encoding 588 amino acids. Altering catechin content through a variety of environmental conditions such as drought stress (DS), abscisic acid (ABA) and gibberellic acid (GA3) treatments, and wounding established a strong positive correlation coefficient between catechins content and the expression of Cs4Cl. In addition, tea clones with high levels of catechins had higher expression of Cs4Cl whereas tea clones with lower catechins exhibited lower expression of this gene. Exposure of tea shoots to 50–100 μM catechins led to down-regulation of the expression of Cs4CL suggesting product-mediated feedback regulation and an important role for the phenylpropanoid pathway in determining catechin yield in tea.
A. S. Roslan, A. Ismail, Y. Ando, and A. Azlan, “Effect of Drying Methods and Parameters on the Antioxidant Properties of Tea (Camellia Sinensis) Leaves,” Food Production, Processing and Nutrition, vol. 2, no. 1, p. 8, Apr. 2020.
doi: 10.1186/s43014-020-00022-0.
Conventional drying using heated air oven is commonly used as a method for preserving the product but often affects the nutritional value, taste, and texture. However, the heat from the drying method can oxidize and destroy heat-sensitive compounds. Superheated steam (SHS) drying uses superheated steam instead of hot air or combustion gases in a direct dryer and was reported better at preserving the nutritional values of food products.
J. Ruan, J. Gerendás, R. Härdter, and B. Sattelmacher, “Effect of Nitrogen Form and Root-Zone pH on Growth and Nitrogen Uptake of Tea ( Camellia Sinensis ) Plants,” Annals of Botany, vol. 99, no. 2, pp. 301–310, Feb. 2007.
doi: 10.1093/aob/mcl258.
S. Safaei Chaeikar, S. Marzvan, S. Jahangirzadeh Khiavi, and M. Rahimi, “Changes in Growth, Biochemical, and Chemical Characteristics and Alteration of the Antioxidant Defense System in the Leaves of Tea Clones (Camellia Sinensis L.) under Drought Stress,” Scientia Horticulturae, vol. 265, p. 109257, Apr. 2020.
doi: 10.1016/j.scienta.2020.109257.
In this study, we measured the morphological, biochemical, and chemical responses to soil drying in nine tea clones [Camellia sinensis (L.) O. Kuntze] grown in a field. Thirteen-year-old tea plants at Shahid Eftekhari Fashalam Experimental Station, Tea Research Center of Iran, were subject to drought stress by withholding water for 40 days. The control group of the clones was regularly watered. The soil moisture content of the non-irrigated and irrigated plants was monitored throughout the experiment. The effects of drought stress were measured by studying physiological (Relative Water Content), biochemical (Proline and Total Sugar Content), and antioxidant activities (Catalase and Peroxidase) after 20 days and 40 days of drought imposition. Green leaf yield and chemical parameters included total polyphenol, caffeine, water extract, and total ash were measured after 40 days of drought stress. Drought stress resulted in a decrease in total polyphenol, water extract, and total ash and an increase in proline, total sugar concentration and, in CAT and POD activities, as a consequence of reduced RWC of the leaves. Thus, drought stress caused a range of biochemical, physiological, and chemical variations, resulting in membrane damage and loss in the functions of the cell and finally a decrease in the tea growth as one of the most important economic crops. The results of grouping the clones under irrigation and drought stress conditions and comparing them with the results of mean comparison of the traits showed that in all cases, clones 276, 100, 285, and 277 were in the group that can be identified as the drought-tolerant group. Also, the results showed that in most cases, clones 278 and 74 were placed in a group that had low values for all the traits and could be considered as a group that is susceptible to drought stress. Overall, these findings provide new insight into the mechanisms of tolerance to drought in tea plants.
G. K. Saikia, A. C. Barbora, and M. K. Deka, “Pest, Disease and Weed Incidence and Crop Yield as Influenced by Organic Culture in Tea [ Camellia Sinensis (L.) O. Kuntze],” Agricultural Science Digest - A Research Journal, vol. 34, no. 2, p. 119, 2014.
doi: 10.5958/0976-0547.2014.00028.7.
K. Saito, “Roots of Hydroponically Grown Tea (Camellia Sinensis) Plants as a Source of a Unique Amino Acid, Theanine,” American Journal of Experimental Agriculture, vol. 4, no. 2, pp. 125–129, Jan. 2014.
doi: 10.9734/AJEA/2014/5122.
The beneficial effects of green tea are well documented. However, most research has reported the effects of green tea brewed solely from leaves or leaf extracts. We focused on tea roots and developed a hydroponic system to explore the effect on roots that biosynthesize one of the rarest functional amino acids, theanine. The level of theanine in tea roots was much higher than in leaves, which was analyzed using HPLC. Moreover, a higher level of theanine was detected in white rootlets than in lignified roots. Thus, tea roots cultured hydroponically in a controlled environment might be considered a natural drug containing theanine, which could lead to synergistic effects with other ingredients of the root. This novel medicinal material from the roots demonstrates a significant medical function for tea that extends beyond its leaves.
S. Sarwar, F. Ahmad, F. S. Hamid, B. M. Khan, and F. Khurshid, “Effect of Different Nitrogenous Fertilizers on the Growth and Yield of Three Years Old Tea (Camellia Sinensis) Plants,” Sarhad Journal of Agriculture (Pakistan), 2007.https://agris.fao.org/search/en/records/64724b0b08fd68d54600b4f4.
Effect of different nitrogenous fertilizers on the growth and yield of three years old tea (Camellia sinensis L) plants was investigated at National Tea Research Institute, Shinkiari, (Mansehra) during 2005-06. The nitrogenous fertilizers used were ammonium sulphate, calcium ammonium nitrate, urea and nitrophos along with control receiving no fertilizer. All the nitrogenous fertilizers were applied at the rate of 100 kg N per acre along with the constant doses of P and K (25 kg, 15 kg per acre, respectively). It was found that effect of all the fertilizers on increase of plant height, plant canopy, fresh tea leaves yield and made tea yield was non significant at 5% probability, however ammonium sulphate produced the highest increase in plant height (63.95 cm), plant canopy (3763.3 cm2), fresh tea leaves yield (1695.50 kg per acre) and made tea yield (339.30 kg per acre) compared to the other fertilizer treatments. Regarding made tea yield, the response of other fertilizers was in the order of nitrophos (327.40 kg per acre), urea (322.80 kg per acre) and calcium ammonium nitrate (314.16 kg per acre) respectively. Minimum made tea yield (253.40 kg per acre) was recorded in control. Ammonium sulphate as a source of nitrogen (100 kg per acre) along with P (25 kg per acre) and K (15 kg per acre) is recorded for the best growth and yield of tea under the agro-climatic condition of Mansehra, Pakistan.
S. Sarwar, F. Ahmad, and F. S. Hamid, “Effect of Nitrogenous Fertilizer on the Growth and Yield of Tea (Camellia Sinensis L.) Pruned in Curved Vs Flat Shape,” J. Agric. Res., 2011.
Effect of nitrogenous fertilizer on the growth and yield of mature tea crop pruned in flat vs curved shape, was studied at National Tea Research Institute, Shinkiari, Mansehra, Pakistan during the year 2010. The layout system was RCBD with split plot arrangement having three replications. The treatments included control (no fertilizer), NPK @125-125-75, 187.5-125-75, 225-12575,312.5-125-75 and 375-125-75 kg per hectare. All P and K were applied as a basal dose while N in the form of ammonium sulphate, was applied in three split doses. The data revealed that flat pruning proved to be the best and gave highly significant results. The nitrogenous level of 375 kg increased fresh leaves yield significantly (6796 to 8797 kg/ha), tea yield (1352 to 1760 kg/ha) and shoot length (35 to 71 cm) over control. In case of interaction, 375 kg N with flat shape pruning produced the highest fresh leaves yield (9286.66 kg/ha) and black tea yield (1857 kg/ha) with a shoot growth of 70.33 cm as compared to curved shape pruning (8307.33 kg fresh leaves, 1661.33 kg black tea and 72.33 cm shoot growth).
D. Sato, “Germinating Tea Seeds (Camellia Sinensis),” Cooperative Extension Service University of Hawaii, Manoa, Hawaii, SCM-17, Mar. 2017.
T. H. Seran, M. T. K. Gunasekare, and K. Hirimburegama, “Germination and Subsequent Plant Development of in Vitro Cultured Zygotic Embryos and Embryonic Axes in Comparison to Conventional Seed Propagation of Tea (Camellia Sinensis L.),” 2007.http://archive.cmb.ac.lk:8080/research/handle/70130/2535.
The present study was carried out to achieve synchronous germination of plant materials into vigorous plants of tea (camellia sinensis 1.), under ex vitro conditions. Sterilized zygotic embryos and zygotic embryonic axes were cultured on MS basal medium supplemented with 3 mg L"1 BAPandO.5 mgL"1 IBA. To serve as controls, seeds were sown in a sand bed. At the 8* week, in vitro plantlets were transferred to ex vitro conditions for acclimatization, and seeds showing different germination responses were separately transplanted. Synchronous and significantly high germination (99%) was observed from cultured embryonic axes in vitro at the 4"’ week of culture, but a lower level of germination (12.7%) from seeds that were sown in the sand bed. Further, healthy plantlets regenerated from embryonic axes in vitro had erect shoots with short internodes, as well as tap roots with abundant adventitious roots under ex vitro conditions, for better adaptation in the field, as compared with seedlings raised by conventional seed propagation.
K. L. Sharma, D. K. Sharma, and G. Sharma, “Long Term Response of Integrated Nitrogen Nutrition with Bioresources on the Yield of China Hybrid Tea (Camellia Sinensis L.) Grown in North-West Himalayas.,” Proceedings of the 15th Plantation Crops Symposium Placrosym XV, Mysore, India, 10-13 December, 2002, pp. 386–391, 2002.https://www.cabdirect.org/cabdirect/abstract/20073116795.
The present study was conducted to find out the long-term response of integrated nitrogen nutrition with bioresources on the yield of China hybrid tea (Camellia sinensis L.) grown in North-West Himalayas. The results of the present study indicated that the treatment combinations of N levels with and without FYM and Azotobacter levels exerted a highly significant influence on the mean yield of tea...
S. Singh, A. Pandey, B. Kumar, and L. M. S. Palni, “Enhancement in Growth and Quality Parameters of Tea [Camellia Sinensis (L.) O. Kuntze] through Inoculation with Arbuscular Mycorrhizal Fungi in an Acid Soil,” Biology and Fertility of Soils, vol. 46, no. 5, pp. 427–433, Jun. 2010.
doi: 10.1007/s00374-010-0448-x.
The present study was undertaken to determine the effect of inoculation with arbuscular mycorrhizal fungi (AMF) from natural and cultivated tea rhizospheres (NTR and CTR, respectively) on growth as well as on quality parameters of tea [Camellia sinensis (L.) O. Kuntze]. Seeds (after germination) and cuttings were inoculated with AMF consortia from NTR and CTR in non-sterilized acid soil (pH 5.0). Seedlings and cuttings were grown under net-house conditions and the data on growth and quality parameters were recorded up to 2 years. Tea plants were found to be highly colonized by AMF (74–83%) after 1 year. The significant increase in most of the growth parameters (root/shoot length, dry weight; r/s ratio) was recorded in AMF-treated plants, which also showed better tea quality parameters than noninoculated plants. Maximum significant increases up to 31% and 100%, over control, were recorded in amino acids and total protein content, respectively. Similarly, maximum increase in total polyphenols (15%) and caffeine content (34%) over control was also significant. Enhanced sugar content (maximum 16% in total soluble sugars, maximum 45% in reducing sugars, and maximum 69% in non-reducing sugars) was recorded in AMF-inoculated plants. In most cases, better response was observed in tea plants inoculated with AMF consortia from NTR. These results indicate that growth and quality of tea can be improved by AMF inoculations in acid soils.
B. G. Smith, W. Stephens, P. J. Burgess, and M. K. V. Carr, “Effects of Light, Temperature, Irrigation and Fertilizer on Photosynthetic Rate in Tea (Camellia Sinensis),” Experimental Agriculture, vol. 29, no. 3, pp. 291–306, Jul. 1993.
doi: 10.1017/S001447970002086X.
Photosynthetic rates were monitored during the warm dry season in tea Clone 6/8 in a line-source irrigation × fertilizer experiment in the Southern Highlands of Tanzania. Irrigation and fertilizer increased photosynthetic rate both by enhancing photosynthetic rate per unit leaf area (A) in healthy leaves and by increasing the proportion of sunlight intercepted by photosynthetically efficient leaves. Irrigation-induced increases in A could be accounted for by increases in stomatal conductance (g) and associated reductions in leaf temperature. Fertilizer at an annual application rate of 225 kg N ha-1 caused increases in A associated with increases in g and improved responses to ambient CO2 concentration and illuminance (photon flux density, PFD). However, a further increase in fertilizer application rate to 375 kg N ha-1 a-1 decreased A in spite of increasing g. Light-saturation of photosynthesis occurred only at the higher fertilizer application rate. In unfertilized tea or tea fertilized at the lower rate, A decreased at a PFD of between 1400 and 2000 μmol m-2 s-l. These results are discussed in terms of the relation between photosynthesis and yield in tea.Fotosíntesis en el té
D. P. Song, G. Jaganathan, Y. Y. Han, G. R. Wu, and B. L. Liu, “Camellia Sinensis Seeds Are Desiccation-Tolerant but Do Not Store Well at Sub-Zero Temperatures,” Seed Science and Technology, vol. 45, pp. 1–6, Dec. 2017.
doi: 10.15258/sst.2017.45.3.06.
D. Song, G. K. Jaganathan, Y. Han, and B. Liu, “Seed Dormancy in Camellia Sinensis L. (Theaceae): Effects of Cold-Stratification and Exogenous Gibberellic Acid Application on Germination,” Botany, vol. 95, no. 2, pp. 147–152, Feb. 2017.
doi: 10.1139/cjb-2016-0149.
There are several different opinions regarding dormancy in tea (Camellia sinensis L.), but there is no strong evidence available to conclude whether or not these seeds are dormant. Freshly matured tea seeds collected from Hangzhou, China, at the natural dispersal time did not germinate in light at daily alternative temperature regimes of 10/15, 15/20, 20/25, or 25/35 °C, or at a constant temperature of 25 °C. Seeds were permeable to water and the embryos did not grow prior to radicle emergence, thus, the seeds have no physical, morphological, or morphophysiological dormancy. When cold-stratified at 4 °C for 1, 2, and 3 months, 64%, 88%, and 93% of the seeds germinated, respectively. Intact fresh seeds failed to germinate after treatment with 0, 10, 500, and 1000 ppm GA3, whereas 3%, 4%, 61%, and 86% of cracked seeds germinated, respectively. Thus, the seeds have nondeep and intermediate physiological dormancy. Seeds cold-stratified for 2 months that were buried at soil depths of 0, 1, and 5 cm in pots showed that seeds at 1 cm depth established significantly higher number of seedlings (P < 0.05) than at other two depths. Because tea seeds are susceptible to summer temperature drying, these seeds do not establish a persistent seed bank.
G. R. Squire, “Weather, Physiology and Seasonality of Tea (Camellia Sinensis) Yields in Malawi,” Experimental Agriculture, vol. 15, no. 4, pp. 321–330, Oct. 1979.
doi: 10.1017/S0014479700012953.
Field measurements with a pressure chamber showed that the water potential of tea shoots was more closely related to the atmospheric saturation deficit than to the amount of water in the soil. Records for shoot growth and weather then revealed that, within a narrow range of mean temperature, the weekly rate of shoot extension was inversely related to mean saturation deficit measured at 1400 h. During periods when saturation deficit did not rise above 20 mbar, the rate of shoot extension varied linearly with mean temperature above a base temperature of 12.5–13.0°C. These correlations suggested that seasonality of shoot growth in tea can be explained largely by the independent effects of temperature and humidity. The effect of mean air temperature on the rate of shoot extension was confirmed in a glasshouse built over an established crop.
G. R. Squire, “Xylem Water Potential and Yield of Tea (Camellia Sinensis) Clones in Malawi,” Experimental Agriculture, vol. 12, no. 3, pp. 289–297, Jul. 1976.
doi: 10.1017/S0014479700100560.
When several clones of tea were grown in neighbouring plots, the xylem water potential was lowest in clones which gave a higher yield. It is unlikely that differences of transpiration rate are involved. Although the physiological link between yield and water potential is still obscure, measurements of potential with a pressure chamber might be used to screen new clones for high productivity at an early stage of growth.
W. Stephens and M. K. V. Carr, “Responses of Tea (Camellia Sinensis) to Irrigation and Fertilizer. I. Yield,” Experimental Agriculture, vol. 27, no. 2, pp. 177–191, Apr. 1991.
doi: 10.1017/S0014479700018822.
The yield responses of clonal tea (Clone 6/8) to irrigation and fertilizer were studied in a field experiment (based on the line-source technique) at a high altitude site (1840 m) in the Southern Highlands of Tanzania over a three-year period. In this area (latitude 8°33′S) the annual dry season can last up to six months with potential soil water deficits reaching 600 to 700 mm. In the third year of the experiments yields for the fully irrigated, well fertilized (375 kg N ha−1) treatments had reached 4.9 t ha−1 of made tea. These were reduced by about 2.9 kg ha−1 for each mm increase in the potential soil water deficit. For tea with little or no fertilizer applied the loss of yield was about 1.4 kg ha−1 mm−1. These figures provide a basis for assessing the potential benefits from irrigation where other factors, such as large saturation deficits of the air, do not restrict shoot extension and yield. Yield responses to nitrogen (applied as N:P:K 20:10:10) were essentially linear up to a maximum of about 375 kg N ha−1 in the fully irrigated plots, and 300 kg N ha−1 for the unirrigated plots. Irrigation increased the proportion of crop harvested during the dry season, up to 45% in the fully irrigated treatments. The commercial implications of these results for ‘high’ and ‘low’ input producers are discussed.
W. Stephens and M. K. V. Carr, “Responses of Tea (Camellia Sinensis) to Irrigation and Fertilizer. II. Water Use,” Experimental Agriculture, vol. 27, no. 2, pp. 193–210, Apr. 1991.
doi: 10.1017/S0014479700018834.
The water use of clonal tea (Clone 6/8) in a line-source irrigation × nitrogen experiment in the Southern Highlands of Tanzania was monitored with a neutron probe during 1987 and 1988 to a depth of 3 m and 1989 to a depth of 5 m. The results for 1989 were used to calibrate a single layer water balance model which was then used to estimate water use for the preceding 1986, 1987 and 1988 dry seasons. In the model evapotranspiration was reduced linearly when the soil water deficit exceeded a critical value of 60 mm. The model predicted water use well for unirrigated, partially irrigated and fully irrigated treatments. Total extractable water was 330 to 350 mm in the 5.5 m deep root zone and estimated annual water use in 1988/89 ranged from 800 mm for unirrigated to 1200 mm for fully irrigated plots, of which about 400 mm was used in the wet season from December to April. Water use efficiencies were between 1 to 4 kg of made tea ha−1 mm−1, increasing with improving water and nutrient status. The slope (b) of the relation between the relative yield loss and the relative reduction in water use was very steep (b = 1.3) reflecting the sensitivity of shoot growth and yield of this clone to water stress.
W. Stephens and M. K. V. Carr, “Responses of Tea (Camellia Sinensis) to Irrigation and Fertilizer. III. Shoot Extension and Development,” Experimental Agriculture, vol. 29, no. 3, pp. 323–339, Jul. 1993.
doi: 10.1017/S0014479700020895.
Rates of shoot extension and development (the unfolding of leaves) were recorded in an irrigation × fertilizer experiment on Clone 6/8 at Ngwazi Tea Research Unit in southern Tanzania. The wide range of mean temperatures (from 15–20°C) meant that the duration of the shoot replacement cycle (the time taken for an axillary bud released from apical dominance to develop three leaves and a terminal bud), in fully irrigated tea receiving 450 kg N ha-l, varied from 65 d in the warm wet season to 95 d in the cool dry season, compared with 75 to 180 d for unirrigated and unfertilized tea. Regression analysis indicated that the base temperature for extension, for Clone 6/8 in high-input plots, was about 10°C, some 2–3°C more than that for development. As a result of these differences in base temperature, the length of shoots with three leaves and a bud varied considerably between treatments and seasons, ranging from 15 mm in the unirrigated plots (at the end of the dry season) to 130 mm in the high-input plots at the start of the rains. Shoots from well fertilized tea were always longer (at a given stage of development) than those from unfertilized tea. The results are discussed in terms of the possible mechanisms responsible for the observed responses (changes in partitioning between roots and shoots), commercial harvesting practices and yield modelling.Extensión y desarrollo de broies en el té
W. Stephens and M. K. V. Carr, “Responses of Tea (Camellia Sinensis) to Irrigation and Fertilizer. IV. Shoot Population Density, Size and Mass,” Experimental Agriculture, vol. 30, no. 2, pp. 189–205, Apr. 1994.
doi: 10.1017/S0014479700024133.
Shoot population densities, stages of development (that is, the number of leaves per shoot) and shoot mass were recorded on an irrigation × fertilizer experiment at the Ngwazi Tea Research Unit in Southern Tanzania from 1986 to 1990. Over this period the mean basal shoot population density increased from about 310 to 560 m−2, with peaks of over 850 m−2 in high-input plots. Large fertilizer application rates increased both the total number of shoots per unit area and the proportion that were actively growing. By contrast, the main effect of water stress was to delay the peak shoot population density from the warm-dry season until the early rains without affecting the annual mean. Overall, between 20 and 60% of the harvested shoots were dormant, depending on season and fertilizer application rate. Of the active shoots harvested, about two thirds had two leaves and a terminal bud whilst the remainder were split almost equally between shoots with one or three leaves. The fresh mass of individual shoots was linearly related to the number of leaves, with the slope of the line (0.16–0.35 g leaf−1) largely dependent on the season and irrigation treatment. The dry matter content of shoots varied in the range 19–30%, and was primarily determined by the season. The dry matter content was also affected by the treatments and was decreased by irrigation in the dry season and by fertilizer in the wet season. Alternative models for predicting annual yields (based on the components of yield) and seasonal yield variations (based on dry matter production and partitioning) are discussed.Densidad de poblacióon tamaño y masa de los brotes de té
W. Stephens and M. K. V. Carr, “Seasonal and Clonal Differences in Shoot Extension Rates and Numbers in Tea (Camellia Sinensis),” Experimental Agriculture, vol. 26, no. 1, pp. 83–98, Jan. 1990.
doi: 10.1017/S001447970001543X.
Shoot extension rates and numbers recorded over an 18 month period in Tanzania from three contrasting clones were analysed to determine variation between and within seasons. Clonal differences in base temperatures for shoot extension ranged from 10.3 to 14.5°C, whilst variability in the response of shoot growth rates to temperature could be ascribed to the shoot selection technique employed. Considerable clonal variation in shoot population densities occurred, with maxima ranging from 200 to 1200 shoots m−2. Total active shoot extension, the product of shoot growth rates and population densities, varied between 4 and 35 m m−2 week−1, shoot numbers being the dominant component. The implications of these results are discussed in terms of shoot measurement techniques, clonal selection criteria, yield modelling and harvesting policies.
W. Stephens and M. K. V. Carr, “A Water Stress Index for Tea (Camellia Sinensis),” Experimental Agriculture, vol. 25, no. 4, pp. 545–558, Oct. 1989.
doi: 10.1017/S0014479700015179.
A simple Stress Time Index (STI) for predicting yield loss in the tea crop due to drought is proposed, based on the daily summation of the difference between the potential soil water deficit and a specified limiting value. Validation of the technique with results from a line-source irrigation experiment with a single clone in the Southern Highlands of Tanzania suggests that there is a linear relationship between STI and relative yield loss during the warm dry season. As a result of changes in the composition of the shoot population at each harvest the apparent critical deficit at which shoot growth is restricted increases from below 20 to 300 mm as the dry season progresses. The rate of yield loss with increasing STI also varies through the dry season for the same reason.
T. Suzuki and G. R. Waller, “Allelopathy Due to Purine Alkaloids in Tea Seeds during Germination,” Plant and Soil, vol. 98, no. 1, pp. 131–136, Feb. 1987.
doi: 10.1007/BF02381733.
During imbibition of whole tea seeds (6 days) two purine alkaloids, caffeine and theobromine, did not decrease in the seed coats and there was no increase in the seeds. In parallel with and after the breaking of seed coats there was a gradual release of caffeine from coats of germinating seeds. By contrast, when the seed was freed from the outer seed coat and soaked, imbibition of the seed required only 2 days and simultaneously caffeine was released from the inner seed coat. In such seeds, but not in whole seeds, growth of embryonic tissues (roots and shoots) was inhibited after the breaking of the inner seed coats. Nevertheless, caffeine increased more in such roots of the seedlings of decoated seeds than in roots of normal seedlings.
I. M. Tabu, V. M. Kekana, and D. M. Kamau, “Effect of Varying Ratios and Rates of Enriched Cattle Manure on Leaf Nitrogen Content, Yield and Quality of Tea (Camellia Sinensis),” Journal of Agricultural Science, vol. 7, no. 5, p. p175, Apr. 2015.
doi: 10.5539/jas.v7n5p175.
Tea (Camelia sinensis) a major cash crop in Kenya is normally grown on highly weathered and strongly acidic soils. Non-judicial use of the recommended inorganic compound fertilizer 25:5:5:5s acidifies the soil and pollutes water masses. Integrated soil fertility management, the combined use of organic and inorganic fertilizer is recommended for higher tea yield and soil health. An experiment was carried out in the Eastern Highlands of Kenya to determine the effect of different ratios and rates of enriched cattle manure on leaf nitrogen content, yield and quality of tea. Inorganic compound fertilizer 25:5:5:5s led to the highest N level in the mature leaf. Enriching organic manures with inorganic fertilizers increased the yield but reduced the quality. Tea quality parameters Theaflavins (TF) and Thearubigins decreased with increase in fertilizer rate irrespective of fertilizer type. Caffeine content however increased with increasing rate fertilizer especially in the case of inorganic compound fertilizer 25:5:5:5. Enriching organic manures with inorganic fertilizers increased the N content in the mature leaf and crop yield but reduced the quality. The study showed the beneficial effect of enriched manures in tea production.
S. Tang et al., “Applying Nutrient Expert System for Rational Fertilisation to Tea (Camellia Sinensis) Reduces Environmental Risks and Increases Economic Benefits,” Journal of Cleaner Production, vol. 305, p. 127197, Jul. 2021.
doi: 10.1016/j.jclepro.2021.127197.
The overuse and unbalanced application of fertilisers have become common practices in the modern world, causing serious environmental problems and restricting tea growth and quality. Therefore, a scientific and rational fertilisation recommendation method should be developed to solve these problems. In this study, fertilisation datasets collected from field experiments (n = 548) in tea-producing areas (n = 21) from 2016 to 2020 were used to build (n = 492) and validate (n = 56) the Nutrient Expert (NE) system for tea. The field validation results indicated that the NE system significantly increased tea yield, quality, economic benefits, and nitrogen (N) use efficiency, as well as decreased greenhouse gas (GHG) emissions. Compared with current farmers’ practice (FP), NE reduced fertiliser-sourced N, phosphorus (P), and potassium (K) application rates by 28%, 25%, and 20%, respectively. On average, NE increased tea yields by 14.0% and 9.3% relative to FP and soil testing (ST). The total concentration of free amino acids, which is one of the most important indexes of green tea quality, were highest in the NE treatment. The net economic benefits of NE increased by 20.0% and 12.6% relative to FP and ST. NE also increased the N utilisation efficiency of tea shoots by 87.0% and 85.3% compared to FP and ST, respectively. Moreover, NE reduced total GHG emissions by 27.7% and 9.6% compared to FP and ST. These results suggest that fertiliser recommendations based on the NE system can increase economic benefits and reduce environmental risks by avoiding excessive fertilisation to maintain sustainable agriculture.
S. Tang et al., “Effects of Balanced and Unbalanced Fertilisation on Tea Quality, Yield, and Soil Bacterial Community,” Applied Soil Ecology, vol. 175, p. 104442, Jul. 2022.
doi: 10.1016/j.apsoil.2022.104442.
Unbalanced fertilisation with nitrogen (N), phosphorus (P), or potassium (K) deficiencies suppresses tea growth and is common in tea production. Balanced fertilisation based on the optimal nutrient requirements of tea plants improves tea yield and quality. However, the effects of unbalanced fertilisation on the yield and quality of tea, soil chemical properties, and bacterial community have not been investigated, and the mechanisms affecting the tea yield and quality remain unclear. Therefore, we conducted a five-year field experiment in tea orchards using four combinations of N, P, and K fertiliser and an unfertilised control. Compared with balanced fertilisation, N, P, and K deficiencies led to a 27.3%, 12.9%, and 11.3% reduction in annual tea yield, respectively. In general, N deficiency had a greater impact on the tea quality than P and K deficiencies. Nutrient contents in tea leaves correlated positively and significantly with tea quality (free amino acid and polyphenol contents). Alpha diversity of soil bacteria was lower in N addition treatments. The addition of N altered the soil bacterial community structure significantly and resulted in a lower Bray–Curtis dissimilarity with respect to the unfertilised treatment. Compared to balanced fertilisation, N deficiency inhibited Chloroflexi but favoured Thaumarchaeota growth. P deficiency resulted in a lower relative abundance of Acidobacteria but a higher relative abundance of Proteobacteria. Fertilisation indirectly influenced soil bacteria with the mediation of pH and soil organic carbon and NH4+ contents. This study indicates that N fertiliser input and pH are the main factors affecting tea yield and quality, respectively. Understanding the effects of unbalanced fertilisation on both tea and soil will help to guide fertilisation strategies, improve tea yield and quality, and reduce the environmental impacts of cultivation.
S. Tang et al., “Temporal Variation in Nutrient Requirements of Tea (Camellia Sinensis) in China Based on QUEFTS Analysis,” Scientific Reports, vol. 10, no. 1, p. 1745, Feb. 2020.
doi: 10.1038/s41598-020-57809-x.
Fertilisation datasets collected from field experiments (n\,= 21) in tea-producing areas from 2016 to 2018 were used to build a quantitative evaluation of the fertility of tropical soils (QUEFTS) model to estimate nutrient uptake of tea plants, and to investigate relationships between tea yield and nutrient accumulation. The production of 1000 kg spring tea (based on one bud with two young expanding leaves) required 12.2 kg nitrogen (N), 1.2 kg phosphorus (P), and 3.9 kg potassium (K), and the corresponding internal efficiencies (IEs) for N, P, and K were 82.0, 833.3, and 256.4 kg kg−1. To produce 1000 kg summer tea, 9.1 kg N, 0.8 kg P, and 3.1 kg K were required, and the corresponding IEs for N, P, and K were 109.9, 1250.0, and 322.6 kg kg−1. For autumn tea, 8.8 kg N, 1.0 kg P, and 3.2 kg K were required to produce 1000 kg tea, and the corresponding IEs for N, P, and K were 113.6, 1000.0, and 312.5 kg kg−1. Field validation experiments performed in 2019 suggested that the QUEFTS model can appropriately estimate nutrient uptake of tea plants at a certain yield and contribute to developing a fertiliser recommendation strategy for tea production.
T. W. Tanton, “Environmental Factors Affecting the Yield of Tea (Camellia Sinensis). I. Effects of Air Temperature,” Experimental Agriculture, vol. 18, no. 1, pp. 47–52, Jan. 1982.
doi: 10.1017/S0014479700013417.
The response of tea shoots to temperature was studied in the field and in controlled environments. Shoot extension stopped below about 12.5°C. Shoots of mature tea took 491 day degrees above the base temperature of 12.8°C to grow to a harvestable size of 15 cm.
T. W. Tanton, “Some Factors Limiting Yields of Tea (Camellia Sinensis),” Experimental Agriculture, vol. 15, no. 2, pp. 187–191, Apr. 1979.
doi: 10.1017/S0014479700000594.
Measurements indicate that the tea crop—which consists of young shoots—is sink-limited and that the plucking of immature shoots, essential for quality tea, is a major factor limiting yields of the crop. The importance of this aspect in selecting for high-yielding plant material is discussed.
K. Teshome, “Effect of Tea Processing Methods on Biochemical Composition and Sensory Quality of Black Tea (Camellia Sinensis (L.) O. Kuntze): A Review,” Journal of Horticulture and Forestry, vol. 11, no. 6, pp. 84–95, Jul. 2019.
doi: 10.5897/JHF2019.0588.
Final quality of black tea depends mainly on the chemical composition of the raw tea leaves. Various plucking methods have direct effect both on yield and quality in different cultivated variety and environments. Different literature reports indicated that polyphenols, caffeine, essential oils and amino acids are responsible for aroma and flavor of black tea. The oxidation process begins at rolling step and ends at initial stages of drying process until the heat denature the enzymes, which convert tea polyphenols (catechins) to theaflavins and thearubigins; both are responsible for brightness, color and taste of black tea. TR increased by increasing fermentation period. TF decreased by increasing fermentation period. The essential oils and the amino acids also contribute to characteristic tea taste and aroma. It was found that the essential oils content increased during the withering, rolling and fermentation steps; however this amount decreased during the drying step. But this reduction is compensated by the Millard reaction which is the reaction of amino acids with the sugars during drying, contributing positively to the tea flavor and color. Theaflavin, thearubigins and total color content of black tea stored in accelerated storage condition decreased slightly when compared with tea stored under normal conditions. It is concluded that plucking (interval, season and standard), processing steps and storage system plays major role in maintaining black tea quality. Key words: Tea processing, black tea, biochemical composition, sensory quality.
S. Venkatesan, S. Murugesan, M. N. K. Ganapathy, and D. P. Verma, “Long-Term Impact of Nitrogen and Potassium Fertilizers on Yield, Soil Nutrients and Biochemical Parameters of Tea,” Journal of the Science of Food and Agriculture, vol. 84, no. 14, pp. 1939–1944, 2004.
doi: 10.1002/jsfa.1897.
F. N. Wachira, “Triploidy in Tea (Camellia Sinensis): Effect on Yield and Yield Attributes,” Journal of Horticultural Science, vol. 69, no. 1, pp. 53–60, Jan. 1994.
doi: 10.1080/14620316.1994.11515248.
Effects of triploidy on yield and some yield components were evaluated in a heterogenous Kenyan population of diploid and naturally occurring triploid tea genotypes. Significant differences were recorded in all the components studied. Triploid clones produced larger and heavier shoots than diploids, with fewer pluckable shoots per unit area. They also regenerated fewer shoots than diploids during the experimental period. The shoot extension rate of actively growing shoots was independent of ploidy. Triploid axillary buds took longer to reach plucking maturity than diploids. Triploid clones also had larger stomata. Phenotypic correlation (rp) evaluated between pairs of combinations of yield components and yield revealed that all components studied were individually weakly correlated with yield except shoot population (number per square meter on the plucking table surface) which had a significant positive correlation with yield. Shoot size traits (i.e. shoot fresh and dry mass, leaf area, internode length, total shoot length, etc) were positively intercorrelated whilst most of the shoot production efficiency traits (shoot density, shoot extension rate, total time of shoot development, regeneration rate) were weakly inter-correlated.
Q. Wan, R.-kou Xu, X.-hui Li, Q. Wan, R.-kou Xu, and X.-hui Li, “Proton Release from Tea Plant (Camellia Sinensis L.) Roots Induced by Al(III) under Hydroponic Conditions,” Soil Research, vol. 50, no. 6, pp. 482–488, Sep. 2012.
doi: 10.1071/SR12099.
The mechanisms for soil acidification induced by tea plant growth are not well understood. Proton release from tea plant (Camellia sinensis L.) roots induced by aluminium (Al(III)) in solution-culture experiments was examined with an automatic titration system, to determine the effect of Al(III) uptake by the plants on soil acidification. Results indicated that the uptake of Al(III) by tea plants led to proton release from their roots and thus an increase in soil acidification. The uptake of Al(III) by tea plants and the amount of protons released from the roots were greater at pH 4.5 than at pH 5.0 and 4.0 and increased with increasing initial Al(III) concentration in the culture solutions. With the same initial pH, the amount of protons released from tea plant roots at a constant pH was much higher than that at non-constant pH. The presence of ammonium increased the amount of protons released from tea plant roots. Therefore, the uptake of Al by tea plants and subsequent release of protons from their roots may be an important mechanism by which they acidify soils in tea gardens.
Y. Wang et al., “Influence of Different Nitrogen Sources on Carbon and Nitrogen Metabolism and Gene Expression in Tea Plants (Camellia Sinensis L.),” Plant Physiology and Biochemistry, vol. 167, pp. 561–566, Oct. 2021.
doi: 10.1016/j.plaphy.2021.08.034.
Nitrogen plays an important role in plant growth and development, with different nitrogen forms also having an impact on carbon/nitrogen metabolism. Unlike most plants, tea plants prefer ammonium over nitrate. In this paper, we focused on how different nitrogen sources regulate the carbon/nitrogen metabolism in tea plants. Tea seedlings of ‘Longjing 43’ were cultivated hydroponically in four different solutions (zero-nitrogen, only NH4+, only NO3− and mixed nitrogen (NH4+: NO3− = 1:1). We analyzed characteristic components of tea plants and related genes in carbon and nitrogen metabolism. Tea polyphenols and catechins representing carbon pool, increased when NO3− was supplied as the nitrogen source, and similar findings were recorded in the zero-nitrogen treatment. The expression of most catechins biosynthesis-related genes was up regulated under NO3− and zero-N treatment, that was associated with tea polyphenols and catechins changes. Compared with NO3− as the nitrogen source, NH4+ and mixed nitrogen treatments had a positive effect on the accumulation of amino acids, especially theanine, glutamate and arginine, and these components contribute to the freshness flavor of tea. The expression of ammonium-assimilation genes was also up-regulated with NH4+ supply. Under mixed nitrogen treatment, the ratio of total polyphenols to free amino acids (PP/AA) was between sole NH4+ and NO3− supply. Therefore, compared with single nitrogen source, carbon and nitrogen metabolism of tea plant was more balanced under mixed nitrogen treatment. The results suggested that NO3− as the nitrogen source promoted the biosynthesis of catechins enriching the carbon pool, whereas NH4+ supply was more conducive to nitrogen metabolism, indicating that different nitrogen sources could affect the carbon and nitrogen balance.
Y. Wang, Z. Yang, and X. Wei, “Sugar Compositions, α-Glucosidase Inhibitory and Amylase Inhibitory Activities of Polysaccharides from Leaves and Flowers of Camellia Sinensis Obtained by Different Extraction Methods,” International Journal of Biological Macromolecules, vol. 47, no. 4, pp. 534–539, Nov. 2010.
doi: 10.1016/j.ijbiomac.2010.07.007.
The sugar compositions, α-glucosidase inhibitory and α-amylase inhibitory activities of polysaccharides from leaves and flowers of green tea (Camellia sinensis) obtained by hot water extraction (HWE), boiled water extraction (BWE) and enzymatic extraction (EE) were investigated. The yields, sugar contents and monosaccharide compositions of tea leaves polysaccharides (TLPS) and tea flower polysaccharides (TFPS) were all significantly affected by extraction methods. The contents of acidic polysaccharides (APS) extracted by BWE and EE were both much more than those by HWE. The yields of TLPS and TFPS were determined as EE>BWE>HWE. Enzyme and higher temperature could improve the contents of APS and yields of TLPS and TFPS. TLPS and TFPS were all mainly composed of Rha, Ara, Gal, Glu and GalA, very little molar contents of GluA, Xyl and Man. It seemed that enzyme extraction could be more conducive to increase the content of Ara, Gal and GaLA. The molecular weights of TFPS were larger than those of TLPS. The molecular weights of polysaccharides obtained by EE decreased. Proteins in tea leaves and tea flowers might be decomposed by EE by observing UV peaks and IR absorption. peaks. The α-glucosidase inhibitory and amylase inhibitory activities of TLPS and TFPS obtained by EE were lower than those by water extracted method. The inhibitory percentages of TLPS and TFPS against α-amylase were all lower than α-glucosidase for different extractions.
M. R. T. Wickramaratne, “Genotype-Environment Interactions in Tea (Camellia Sinensis L.) and Their Implications in Tea Breeding and Selection,” The Journal of Agricultural Science, vol. 96, no. 2, pp. 471–478, Apr. 1981.
doi: 10.1017/S0021859600066259.
An analysis of yield data from 31 tea clones grown in replicated trials at four locations revealed the presence of significant genotype-environment interactions. Joint regression analysisshowed that a significant proportion of these interactions could be attributed to differences in the linear response of each genotype (clone) to the range of environments. However, estimates of the deviations from regression were also significant, indicating the presence of some unpredictable variation.The response of each individual clone was estimated by computing the regression coefficient of individual yield on environmental mean yield at each location. The clones used in this study had regression values ranging from 0·19 to 2·08, indicating considerable genotypic difference in response to environmental change. Genetic variation in adaptation was also found to be present. Clones of the Assam type were found to possess general adaptation whereas the one clone of Indo-Chinese origin was specifically adapted to low-yielding environments.Some known features of several tea clones are explained on the basis of the linear regression model and a more scientific basis is provided for the recommendations of clones for differentdistricts. The implications of genotype-environment interactions in practical tea breeding and selection are also discussed.
M. A. Wijeratne, A. Anandacoomaraswamy, M. K. S. L. D. Amarathunga, J. Ratnasiri, B. R. S. B. Basnayake, and N. Kalra, “Assessment of Impact of Climate Change on Productivity of Tea (Camellia Sinensis L.) Plantations in Sri Lanka,” Journal of the National Science Foundation of Sri Lanka, vol. 35, no. 2, p. 119, Jun. 2007.
doi: 10.4038/jnsfsr.v35i2.3676.
A study was undertaken to assess impact of climate change on productivity of tea lands in Sri Lanka. Findings of the study showed that tea cultivations at low and mid elevations are more vulnerable to adverse impacts of climate change than those at high elevations. The optimum temperature for tea cultivation was found to be about 22 °C. The study also indicated that reduction of monthly rainfall by 100 mm could reduce the productivity by 30 - 80 kg of ’made’ tea ha"1. In different tea growing regions, the optimum rainfall for tea cultivation varied from 223 to 417 mm per month. Increase in ambient C02 concentration from the present ambient level (around 370 ppm) to 600 ppm, increased the tea yield by about 33-37 % depending on the elevation. Based on these estimated parameters, a simple crop model was developed for predicting tea yield under future climate scenarios. The model was incorporated into a special software package developed to assess impact of climate change on productivity of tea plantations. Yield projections by the crop model showed that rising temperatures and diminishing rainfall reduce tea yield in many tea growing regions except Wet zone Up country (WU). The results also predicted that tea yields are likely to increase at high elevations while the yields at low elevations are likely to reduce due to climate change. Hence, sustainable adaptation measures are proposed to minimize such adverse effects.
E.-H. Xia et al., “The Tea Tree Genome Provides Insights into Tea Flavor and Independent Evolution of Caffeine Biosynthesis,” Molecular Plant, vol. 10, no. 6, pp. 866–877, Jun. 2017.
doi: 10.1016/j.molp.2017.04.002.
Tea is the world’s oldest and most popular caffeine-containing beverage with immense economic, medicinal, and cultural importance. Here, we present the first high-quality nucleotide sequence of the repeat-rich (80.9%), 3.02-Gb genome of the cultivated tea tree Camellia sinensis. We show that an extraordinarily large genome size of tea tree is resulted from the slow, steady, and long-term amplification of a few LTR retrotransposon families. In addition to a recent whole-genome duplication event, lineage-specific expansions of genes associated with flavonoid metabolic biosynthesis were discovered, which enhance catechin production, terpene enzyme activation, and stress tolerance, important features for tea flavor and adaptation. We demonstrate an independent and rapid evolution of the tea caffeine synthesis pathway relative to cacao and coffee. A comparative study among 25 Camellia species revealed that higher expression levels of most flavonoid- and caffeine- but not theanine-related genes contribute to the increased production of catechins and caffeine and thus enhance tea-processing suitability and tea quality. These novel findings pave the way for further metabolomic and functional genomic refinement of characteristic biosynthesis pathways and will help develop a more diversified set of tea flavors that would eventually satisfy and attract more tea drinkers worldwide.
Q.-H. Yang et al., “Seed Biology and Germination Ecophysiology of Camellia Nitidissima,” Forest Ecology and Management, vol. 255, no. 1, pp. 113–118, Feb. 2008.
doi: 10.1016/j.foreco.2007.08.028.
Camellia nitidissima Chi (Theaceae) is a famous ornamental species with golden-yellow flowers. Due to deforestation and destructive collection of seedlings, its natural population size has been reduced greatly in recent decades. To provide basic information for its conservation, we studied the morphological and physiological characteristics of seeds and the environmental factors influencing germination. The seed production of C. nitidissima was of low yield, which caused lack of seed resource. The seeds were big and heavy, so they did not spread far from the mother trees and did not enter soil after falling down. Optimal temperatures for seed germination were 25–30°C. The fresh-harvested seeds had high moisture content and weak desiccation-tolerance, so they tended to be recalcitrant. Soaking for 24h in 10–30% PEG solution could significantly reduce the seed germination percentage. The imbibed seeds placed on the soil surface mostly could germinate, but some of them could not develop into seedlings because the embryo roots did not grow into soil. When the seeds were sowed at the depth of 1cm, the seedling emergence reached over 70%, but then decreased with increased sowing depth, and reached about 50% when at the depth of 5cm. The seeds sowed in sandy soil had higher emergence than those in clayed soil. It is feasible for seedling nursing to harvest seeds in time, harvesting prematurely or postmaturely may reduce seed quality.
F. Zaman et al., “Natural Variation of Main Biochemical Components, Morphological and Yield Traits among a Panel of 87 Tea [Camellia Sinensis (L.) O. Kuntze] Cultivars,” Horticultural Plant Journal, Aug. 2022.
doi: 10.1016/j.hpj.2022.08.007.
Many attentions have been previously focused to identify the multiple biochemical components related to tea quality and health benefits, however, the natural variation of biochemical components present in tea germplasm has not been adequately evaluated. In this study, the main biochemical components, leaf morphological and yield characteristics were evaluated for four rounds of tea leaves in a panel of 87 elite tea cultivars suitable for black, green, or oolong tea. Significant variations were observed among the tea cultivars, as well as seasonal differences in the levels of the free amino acid (FAA), caffeine (CAF), tea polyphenols (TP), water extract (WE) and TP to FAA ratio (TP/FAA). Results showed that the average levels of FAA showed a seasonal change, with the highest level of 4.0% in the 1st spring tea in the cultivars suitable for green tea and the lowest of 3.2% in summer tea in the cultivars suitable for black tea. The average CAF content was highest 3.2% in the cultivars suitable for oolong tea in the 1st spring and the lowest 2.5% in the cultivars suitable for green tea in summer. Limited seasonal and varietal variations were noticed in the average levels of WE among the three categories of tea. In addition, significant natural variation of the morphological characteristics, bud length varying from 2.5 cm to 8.7 cm, bud density from 190.3 buds m-2 to 1 730.3 buds m-2, mature leaves biomass from 128.4 kg.hm-2 to 2 888.4 kg·hm-2, and yield component traits of 100 buds (one bud with two leaves) dry weight from 3.7 g to 37.7 g, tea yield/round from 444.6 kg·hm-2 to 905.3 kg·hm-2, were observed. The aim of our evaluation was not only to identify the advantages of seasonal and clonal variations but also to provide a new viewpoint for their further application. Representative accessions were selected from the germplasm to promote the establishment of an inherent biochemical constituent expressing the quality of black, green, and oolong tea. The findings might be utilized to establish early selection criteria to enhance the tea breeding and production program.
L. Zhang et al., “Effects of Exogenous TIBA on Dwarfing, Shoot Branching and Yield of Tea Plant (Camellia Sinensis L.),” Scientia Horticulturae, vol. 225, pp. 676–680, Nov. 2017.
doi: 10.1016/j.scienta.2017.07.060.
2,3,5-Triiodobenzoic acid (TIBA) is a safe and efficient synthetic auxin transport inhibitor. The mature tea plants of the cv. Longjing 43 were used in this study. The foliar portion of tea bushes were sprayed with different concentrations (50, 100, or 150mgL−1) of TIBA after heavy pruning (i.e., after two to three leaves grew out in late May). The effects of TIBA on the growth of the new shoots and lateral branches were explored. After 5 months, treatments with 50, 100, and 150mgL−1 TIBA decreased plant height by 13.5%, 22.9%, and 23.3%, respectively; TIBA at 50, 100, and 150mgL−1 decreased the number of lateral branches by 18.0%, 18.6%, and 8.4%, respectively. Treatments with 100mgL−1 TIBA increased the length of lateral branches by 34.3%; 50 and 100mgL−1 TIBA increased the lateral branch diameter by 9.45% and 12.46%, respectively. After 2 months, 50 and 100mgL−1 TIBA did not significantly affect photosynthetic rate in comparison with the control. Furthermore, 100mgL−1 TIBA significantly increased spring tea yield by 19.3% in comparison with the control. In conclusion, the treatment of 100mgL−1 TIBA can promote dwarfing, and formation of effective lateral branches, and spring tea yield. It is suggested to spray ‘Longjing 43′ tea plants with 100mgL−1 TIBA solution after heavy pruning in summer (i.e., after two to three leaves grew out in late May).
L. Zhang, C. Shen, J. Wei, and W. Han, “Effects of Exogenous 6-Benzyladenine on Dwarfing, Shoot Branching, and Yield of Tea Plant (Camellia Sinensis),” HortScience, vol. 53, no. 5, pp. 651–655, May 2018.
doi: 10.21273/HORTSCI12892-18.
6-Benzyladenine (6-BA) is a safe and efficient cytokinin. The adult tea plants of the cv. Longjing 43 were used in this study. The foliar portion of tea bushes were sprayed with different concentrations (50, 100, 200, or 400 mg·L−1) of 6-BA after heavy pruning, when three to four leaves grew out in late May. The effects of 6-BA application on the growth of the new shoots and lateral branches were quantified. After 5 months, treatments with 50, 100, 200, or 400 mg·L−1 6-BA suppressed plant height by 11.0%, 18.0%, 21.0%, or 22.0%, respectively; 6-BA at 100, 200, or 400 mg·L−1 decreased the number of lateral branches by 20.0%, 23.0%, or 18.0%, respectively. Meanwhile, treatments with 50, 200, or 400 mg·L−1 6-BA increased the length of lateral branches by 38.0%, 79.0%, or 81.0% respectively; 200 mg·L−1 6-BA increased the diameter of lateral branches by 8.0%. In addition, after 2 months, 50 or 200 mg·L−1 6-BA did not significantly affect the growth of functional leaves, 50, 100, or 200 mg·L−1 6-BA did not significantly affect photosynthetic rate (Pn) as compared with the control. Furthermore, 200 or 400 mg·L−1 6-BA significantly increased spring tea yield by 28.9% or 13.3%, respectively as compared with the control. In conclusion, 6-BA at the four concentrations promoted dwarfing and the formation of productive lateral branches and increased the spring yield, and 200 mg·L−1 6-BA exerted the best comprehensive effect.