International Journal of Tea Science最新文献

{"title":"Radiation Use Efficiency and Yield Responses of Clonal Tea (Camellia sinensis) to Locations of Production","authors":"K. Nyabundi, P. Owuor, G. Netondo, J. Bore","doi":"10.20425/IJTS1414","DOIUrl":"https://doi.org/10.20425/IJTS1414","url":null,"abstract":"Tea in Kenya is grown in the high and medium rainfall areas of the Kenyan highlands in east and west of the Rift Valley, at altitudes ranging from 1300 to 2700 m above mean sea level. Variability in responses of tea genotypes to different environments affects the growth, productivity, and quality of tea. The annual receipt of total shortwave radiation received at any site is determined by the latitude and local climate. Within tea growing regions of Eastern Africa, the main receipt of solar radiation varies from 6500–6700 (MJm-2y-1) at Mufindi, southern Tanzania and Kericho, Kenya, (0022’S 350 21’E) to 7400 MJm-2y-1 at Mulanje, Malawi. Seasonal variations in solar radiation within the year also occur and incident solar radiation at high altitudes can exceed 1000Wm-2. However, the net available energy at the surface of a tea canopy reaches only 100Wm-2. Differences in total light penetration occur among tea varieties. The weight of tea shoots in any one harvest depends on the number developing shoot per unit area, their rate of growth and the average weight of shoots at harvest. Yield components of tea are determined by dry matter production and partitioning. The yield of a tea crop is not primarily limited by the production of dry matter, but by the proportion of the total dry matter partitioned into the “economic yield” of harvestable shoots the harvest index (HI; %). Differences in ground cover, total dry matter and dry matter partitioning between clones and between sites have been attributed to the differences in daily intercepted solar radiation which differ between sites. Nevertheless, dry matter production rates have not been determined for the different Kenyan grown clones in the various tea growing regions of Kenya. A study on 12 clones to evaluate the relationships between the intercepted radiation and its derivatives, environmental factors and yields among selected tea clones in different geographical locations, was conducted on a genotype × environment comprising 20 cultivars laid in a randomized complete block design replicated 3 times, at three locations (Kipkebe, Timbilil and Kangaita). The conversion efficiency, the proportion of radiation intercepted by the canopy, extinction coefficient, incident radiation, and temperature, combined were highly and strongly correlated to yield. However, the only altitude was a significant determinant of conversion efficiency. Altitude is a significant determinant of radiation conversion efficiency and through the efficiency of conversion varies with the location it only contributes to the overall locational parameters that determine yield, the strongest determinant being temperature. Harvest index radiation use efficiency can, therefore, be used as a yield predictor in clonal tea breeding programmes.","PeriodicalId":130789,"journal":{"name":"International Journal of Tea Science","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129379198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Geographical Area of Production on the Caffeine and Flavan-3-ol Profiles of Selected Clonal Green Tea Leaves from Smallholder Tea Farms in Kenya","authors":"M. T. Mose, S. O. Ochanda, K. O. Moseti, J. Wanyoko, P. Owuor, J. Kinyua, D. Kariuki, E. Magiri, M. Obanda","doi":"10.20425/IJTS14116","DOIUrl":"https://doi.org/10.20425/IJTS14116","url":null,"abstract":"Despite the use of similar cultivars in the smallholder tea sector in Kenya, resultant black tea quality varies. These variations could in part be arising from the formation of varying quantities and ratios of the black tea quality precursor compounds with agro-ecological zones of production. This study evaluated the variations in the caffeine and flavon-3-ol profiles of three cultivars (SFS 150, TRFK 31/8 and TRFK 303/577) of tea from smallholder tea farms in three agro-zones in Kenya. Overall, there were significant variations (p less than or equal to0.05) in the levels of caffeine and flavan-3-ols due to cultivars and agro-ecological zones of production. In the same cultivar, the components varied (p less than or equal to0.05) with an ecological area of production. The patterns in the changes were not systematically leading significant ecological zone x cultivar interactions effects in gallic acid, catechin, and epicatechin gallate. This demonstrated that it may not be predictable how the quality of clonal tea may vary when produced in different agro-ecological zone. Consequently, a high-quality clone in one agro-ecological zone may not replicate the same characteristics in the different agro-ecological zone. It is, therefore, necessary to test new clones in new environments before they are extensively exploited in these environments. The current findings suggest that flavon-3-ols may not be potential factors in the discrimination of tea quality within the ecological zones of Kenya.","PeriodicalId":130789,"journal":{"name":"International Journal of Tea Science","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121435360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Black Tea: A Possible Multitherapeutic Combinatorics Aiding Neuroprotection in Alzheimer’s Disease","authors":"K. Bhandari, Baishakhi De, G. Saha, T. K. Goswami","doi":"10.20425/IJTS1419","DOIUrl":"https://doi.org/10.20425/IJTS1419","url":null,"abstract":"This article aims at reviewing the effectiveness of compounds in black tea in combating neuroinflammation in Alzheimer’s disease (AD). Detailed chemo profiling of black tea showed the presence of theaflavins, different catechins, and amino acids viz., L-theanine and methylxanthines. A literature search showed a multitude of pharmacological activities diversity of black tea. Structural and anti-inflammatory activity relationship studies showed the anti-inflammatory potentials of benzotropolone moiety containing compounds, flavonoids, flavones, phenolics and methylxanthines e.g. caffeine, theobromine, theophylline. Black tea is a good source of several multifunctional pharmacophores and thus can combat neuroinflammation in AD providing neuroprotection from multidimensional perspectives.","PeriodicalId":130789,"journal":{"name":"International Journal of Tea Science","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117135576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EFFECTS OF EPIPHYTES ON TEA PRODUCTION AND THEIR MANAGEMENT","authors":"E. Cheramgoi, J. Langat, R. Mose, C. Mutai","doi":"10.20425/IJTS1411","DOIUrl":"https://doi.org/10.20425/IJTS1411","url":null,"abstract":"Epiphytes are a group of non-parasitic plants that settle to obtain support from plants. Under the natural forest ecosystem, the presence of epiphytes is an indicator of unpolluted and undisturbed environment. However, massive infestation by epiphytes to commercial tree crops including tea is a concern to productivity. A study was conducted initiated to determine the influence of different management options on epiphytes which included mosses, ferns, maidenhair ferns, and tongue ferns. The study evaluated the influence of different management options on epiphytes and to determine the effect of the management options on tea yields. The experiment was laid on a field infested with epiphytes in split plot design treatment structure in a randomized complete block layout, replicated three times. In the main plots the epiphytes were manually removed from the tea bush branches whereas the control was left in situ while the subplots involved use of agricultural chemicals; Copper Nordox, Cuprocaffaro, Milraz, Hydrate of lime, Round up Turbo and control (untreated). Post-treatment scoring for 3 years of all types of epiphytes was done using a scale to determine the level of yellowing, scorching, and regrowth. Yield data were also recorded for one prune cycle of four years and data was subjected to analysis of variance. The main treatments (disturbed and undisturbed) management options did not influence the efficacy of the chemical products on epiphytic mosses but disturbance reduced (p less than or equal to0.05) levels of the epiphytic ferns. Copperbased products (Copper Nordox and Cuprocaffaro) reduced (p less than or equal to0.05) in mosses levels (reducing the degree of yellowing and regrowth) than other products and the control. However, all chemical products reduced (p less than or equal to 0.05) levels of epiphytic ferns. The removal of epiphytes on the tea branches increased (p less than or equal to0.05) the yield of tea, while chemical products were ineffective in improving yields. This study, therefore, concludes that the epiphytes on the tea frame have effects on the functioning of the tea bush and removal of the massive epiphytes is necessary for improved productivity of tea bush.","PeriodicalId":130789,"journal":{"name":"International Journal of Tea Science","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133279041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fertilizer Response and Environment Interactions of Yield and Yield Components of Clonal Tea (Camellia Sinensis) in Kenya","authors":"K. Nyabundi, P. Owuor, G. Netondo, J. Bore","doi":"10.20425/ijts1412","DOIUrl":"https://doi.org/10.20425/ijts1412","url":null,"abstract":"Tea is an important cash crop, providing income and employment to rural populations in many countries. In Kenya, tea is the leading export commodity crop and is grown in highlands east and west of the Rift Valley at altitudes ranging from 1300 to 2700 m above mean sea level. This has significant effects on growth, productivity, tea quality and response to fertilizer and has been particularly noted for the popular, widely planted, quality clone TRFK 6/8. In East Africa, tea husbandry practices are uniform despite the variations in responses to agronomic inputs. Fertilizer is the most expensive input in tea production after plucking. In tea, nitrogen availability is the most limiting crop growth factor. However, responses of tea yields to fertilizer application vary with the region of production even with the same cultivar. The utilization of nitrogen, therefore, varies with location. The responses in growth and yield parameters of clonal tea TRFK 6/8 and their contribution to yields were investigated across different environments, in a trial setup in three locations in the east of the Rift Valley in Kenya, using clone TRFK 6/8, a popular commercial cultivar. Yield and yield components response to nitrogen rates varied with location. The highest yields were not always attained at the highest nitrogen levels and the best response to fertilizer did not translate to the highest yields. Tea crop response to fertilizer is the site-specific and universal application of fertilizer may only apply as a general guideline but will not optimize production.","PeriodicalId":130789,"journal":{"name":"International Journal of Tea Science","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116299891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Blended Fertilizers on Yields of Mature Clonal Tea grown in Kenyan Highlands","authors":"S. Kibet, Kamiri W Hellen, N. Gilbert, Kamau M David, N. K. Wilson, M. Maureen","doi":"10.20425/IJTS1415","DOIUrl":"https://doi.org/10.20425/IJTS1415","url":null,"abstract":"Fertilizer requirement for tea production is high since the pluckable portions are succulent shoots, which contain the largest percentage of nutrients. Kenya’s tea industry depends predominantly on imported compound NPK fertilizer to replenish nutrients removed through plucking. These fertilizers cannot be easily manipulated for specific soils and tea clones. This has necessitated studies on other fertilizers which can be produced locally in an economical manner so as to boost farmers’ profit. The objective of this research was to evaluate two Mavuno fertilizer blends with the aim of identifying optimal levels of application which would maximize tea productivity. This was achieved through determination of seasonal and annual effects on tea yields at different rates of application.","PeriodicalId":130789,"journal":{"name":"International Journal of Tea Science","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126303006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal Variations in Catechins and Caffeine Profiles\u0000among Tea Cultivars Grown in Kenya","authors":"Cheptot Lilian, Maritim Tony, K. Robert, K. Emily, Kamunya Samson, Matasyoh Lexa, Muoki Richard","doi":"10.20425/IJTS1418","DOIUrl":"https://doi.org/10.20425/IJTS1418","url":null,"abstract":"Consumption of beverage tea rich in flavonoids is associated with a wide range of health benefits. However, the industry in Kenya has over-relied on black tea whose sustainability is not guaranteed due to glut in the market resulting in low income to farmers. Product characteristics and prices are determined based on the accumulation of the phenolic compounds that are profoundly influenced by environmental and cultivar differences. Profiles of quality-related components were assessed in six new and existing cultivars over three distinct annual seasons. Weather data indicated the wet-cold (April–August) season received the largest amount of precipitation and highest relative humidity, while the hot-dry season (January to March) was the driest with a lower relative humidity. Total catechin (TC) contents were significantly\u0000(P less than or equal to0.05) different among the cultivars, seasons, and interactions season x site and cultivar x season x site. Overall, the purple-leafed cultivars had lower TC content compared to the green-leafed teas, whereas teas obtained during the WW season (September–December) had higher levels (14.3%) that are suitable for processing of high-quality tea products. Esterified catechins, EGCG and ECG, formed the major component among individual catechins studied. EGCG was significantly higher during both the CW and WW seasons. Cultivars of ‘China type’ accumulated higher +C content as compared to the ‘Assam type’. EC was highest during the WW season in Timbilil, while in Kangaita, the CW season had slightly higher content. Generally, the Cambod type cv. TRFK 301/1 had the highest caffeine content, while China type cv. TRFK 73/1 had the lowest content. Unlike catechin, caffeine content was highest during the HD season. This information is crucial for interventions on product diversification, value addition and novel marketing strategies in tea.","PeriodicalId":130789,"journal":{"name":"International Journal of Tea Science","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122793277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response of Plain Black Tea Parameters, Individual Theaflavins and Yields Due to Location of Production and Clones within Lake Victoria Basin","authors":"P. Owuor, P. Ogola, S. Kamunya","doi":"10.20425/IJTS1413","DOIUrl":"https://doi.org/10.20425/IJTS1413","url":null,"abstract":"Tea (Camellia sinensis) is a major cash crop and leading foreign exchange earner, contributing to poverty alleviation by providing employment and livelihood to many stakeholders in the producing countries. Production has increased faster than consumption causing price stagnation, especially for CTC black teas. Kenya is the third-largest tea producer and Lake Victoria Basin produces over 60% of her tea. Selection of tea cultivars in Kenya has been cantered in one location before the selected clones are introduced to other growth environments. This study evaluated if tea clones maintain their yield and plain black tea quality attributes when grown at different locations within Lake Victoria Basin. The basin produces mainly plain black teas whose quality is due to levels of polyphenolic compounds, especially green leaf flavan-3-ols that are oxidized to theaflavins and thearubigins during black tea processing. The theaflavins and thearubigins contribute to the color and brightness of black teas. The trials were done in two sites Timbilil and Kipkebe using twenty clones. All the plain tea quality parameters including individual theaflavins and yields varied (p less than 0.05) with clones, demonstrating diversity in the cultivars used. The levels of the parameters and yields also changed (p less than 0.05) with the location of production. These results demonstrated that clonal tea quality and yields vary depending on the geographical location of production. There were also significant interactions effects between the clones and location of production in the quality parameters and clones showing the extent of the changes varied from clone to clone. Indeed the relative ranking of the clones varied with location. No clone retained its relative superiority ranking at the two locations. Both the Spearman correlation coefficients (rs) and the Pearson correlation coefficients (r) between the individual parameters were positive but low and insignificant, except for theaflavin-3-gallate. These results demonstrate the need for location-specific evaluation of both new and old clones to establish clonal yield and quality potentials in new locations of cultivation.","PeriodicalId":130789,"journal":{"name":"International Journal of Tea Science","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130119652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Catechins and Plain Black Tea Parameters Variations in Selected Tea Growing Agro-Ecological Zones in Kenya","authors":"M. T. Mose, S. O. Ochanda, K. O. Moseti, J. Wanyoko, P. Owuor, J. Kinyua, D. Kariuki, E. Magiri, Obanda","doi":"10.20425/IJTS1417","DOIUrl":"https://doi.org/10.20425/IJTS1417","url":null,"abstract":"Over 60% of tea in Kenya is produced by smallholder tea farmers distributed in the East and West of the Rift Valley. With all smallholder tea farmers using the same production technologies including planting materials, the quality of tea from different agro-ecological zones should be the same. However, black teas attract different prices. This study compared levels of leaf quality, catechins, and polyphenols in green leaf and quality parameters of black tea from twelve factories in three different agro-ecological zones in Kenya and assessed the relationships between the green leaf quality parameters and black tea quality parameters. The catechins contents, the black tea quality parameters, and sensory evaluations changed (p less than or equal to0.05) between the factories and with an agro-ecological zone of production. All black teas had high antioxidant activities, which differed (p less than or equal to0.05) across the factories and zones. Despite the use of same agronomic inputs in the smallholder tea growing zones in Kenya, the quality of resultant black teas was largely influenced by the environmental factors in the different regions. It is therefore not possible to produce black teas of the same quality across the country. Despite the variations, all regions exhibited high levels of black tea quality parameters and sensory evaluation, re-affirming the Kenyan smallholder black teas are of high quality. The high antioxidant activities suggest possible beneficial pharmacological activities from consumption the teas. The green leaf quality (leaf count) were significantly (p less than or equal to0.05) correlated with black tea brightness and all sensory evaluation parameters, demonstrating high benefits from good plucking standards. Green leaf gallic acid, epigallocatechin, epicatechin, epigallocatechin gallate, and total catechins levels were related (p less than or equal to0.05) to black tea total polyphenols and all sensory evaluation parameters. In addition, the green leaf caffeine, epicatechin, epigallocatechin gallate, and total catechins influenced\u0000(p less than or equal to0.05) theaflavins in black tea. These green leaf parameters are therefore key drivers of Kenyan plain black tea quality.","PeriodicalId":130789,"journal":{"name":"International Journal of Tea Science","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127041435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}