Tea Growing Research Articles

Residue Degradation and Risk Assessment of Difenoconazole and Its Metabolite during Tea Growing, Processing and Brewing by Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry Determination.

Residue dissipation and risk assessment of difenoconazole and its metabolite difenoconazole-alcohol during tea growing, processing, and brewing was first investigated by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The limits of quantification for both difenoconazole and difenoconazole-alcohol were 0.001 mg/kg in fresh tea leaves and tea, and 0.0002 mg/L in tea infusion. In field trials, the dissipation half-lives of difenoconazole in fresh tea leaves was 1.77 days. After spraying, the residues of difenoconazole-alcohol increased and then gradually dissipated like difenoconazole. After 14 days, the dissipation rates of difenoconazole and difenoconazole-alcohol reached 99%. When fresh tea leaves were harvested on different days, the total processing factors (PFs) of difenoconazole and difenoconazole-alcohol for green tea were 0.86-1.05 and 0.78-0.85, respectively, while the total PFs for black tea were 0.83-1.13 and 0.82-1.66, respectively. Metabolism of difenoconazole was accelerated during tea processing. When brewing black tea, the leaching rates (LRs) of difenoconazole and difenoconazole-alcohol were 8.4-17.9% and 31.8-38.9%, respectively, while when brewing green tea, the LRs were 15.4-23.5% and 30.4-50.6%, respectively. The LRs of difenoconazole and difenoconazole-alcohol in black tea were higher than those in green tea. The potential threat to human health for dietary intake of difenoconazole and difenoconazole-alcohol residues from tea consumption is negligible. However, the dietary risk of difenoconazole in fruits and vegetables that are essential for daily diets is concerning, with a risk probability of 158%.

Analysis of Tea Agroforestry System: The Case of Kyenjojo District in Uganda

Uganda is one of the countries in east Africa where agroforestry farming system has spread in twelve agro-ecological zones. Agroforestry practices are critical in all agro-based sectors like tea industry because of benefits like provision of fuel wood for curing tea. The purpose of this study was to understand the current agroforestry practices adopted by smallholder tea estate farmers and investigate options for scaling up the technology to alleviate the fuelwood scarcity faced by tea industries. The study involved a survey that was conducted in Kyenjojo district located in Western Uganda in June 2020. A total of 65 small holder tea farmers (respondents) were interviewed during the study. A purposive sampling method was used and data analyzed with SPSS to generate descriptive statistics that included frequencies, percentages, tables, graphs and charts. Results showed that shade was the most benefit of agroforestry trees by a proportion of 33% towards tea growing and followed by climate modification at 24%. Protection of the environment was also revealed as one of the leading benefits of tea agroforestry with a proportion of 34%, as well as trees acting as a source of poles at 23%. Eucalyptus at 34% was the most dominant agroforestry tree used at tea farm level as a woodlot, followed by Grevillea robusta at 28%. The most dominant adoption method of tea agroforestry practices at tea farm level was through farmers learning from fellow farmers at 34%, followed by adoption by trainings at 23%. Planting of agroforestry trees was the only remedy stated by farmers as an effort done to retain trees on farm. As a recommendation towards increased uptake of agroforestry at farm level, farmers identified certification and other factory-based incentives such as Rain Forest Alliance being the most important. Based on the identified benefits of tea-agroforestry systems, efforts should be made by Public, Private and Development partners to make all tea farmers aware of the existing and appropriate agroforestry practices while developing appropriate incentive models for increased adoption of tea agroforestry system in Uganda.

Spatiotemporal trends and factors influencing online attention for China’s tea industry

In the context of the “Internet plus” era, the study of tea industry online attention is a new perspective in research on the tea industry and an opportunity for the sustainable and high-quality development of this industry. Based on the Baidu index, this paper obtains web attention data from 2012 to 2021, analyzes the spatial and temporal evolution characteristics of online attention using the seasonal concentration index and geographic concentration index, and quantitatively discusses the influencing factors using correlation analysis and GeoDetector. The results show the following: The interannual change in China’s tea industry online attention shows “rapid growth, high level of stability, slow decline,” the monthly distribution has an intense concentration, mainly in March-April and October, and the interday distribution of attention peaks on weekdays. The spatial distribution shows an intense geographical concentration, with an overall trend of “light concentration first, then light dispersion.” The migration trajectory of the center of attention is tilted toward the southwest. Economic development status, residents’ income, the natural environment of tea growing, the leisure time of followers, and the price level of tea are the essential factors affecting the of the tea industry online attention. In contrast, the other factors we have chosen have a weaker impact on online attention compared to the few factors just mentioned.

The Impacts of Tea Production in the Socio-Economic Development of Rungwe District of Tanzania, 1960-2020

The study aims at analyzing and examining the impact of tea production in Rungwe District in Tanzania from 1960 – 2020. Tea has been grown in this area since pre-colonial time until to date. This, however, has not been without impacts to the people of Rungwe. These impacts have not been actively put down in order to help the present and future generation learn and cope with global changing techniques and methods of modern tea farming. The study has used historical approach and integrated the agricultural policies as a way of analyzing the impacts of tea production in Rungwe District of Tanzania. The study has used the qualitative and quantitative methods and data was collected through interviews from the key informants and documentary reviews. The study revealed that tea production contributed to the transformation of Rungwe District from rural to urban. The study also suggests that, the impact of tea growing has continued changing depending on the signs of the times. For instance, when the political juggles change, such as nationalization and privatization of national resources, the policies also change and, hence, the impacts change. All these have been meticulously tackled in this study.

Effect of inorganic NPK fertilizer on tea (Camellia sinensis) production in Ruhaija village, Burere Subcounty, Buhweju District, Uganda

The study was conducted to examine the effect of inorganic NPK fertilizer on production of Camellia sinensis in Ruhaija Village Burere sub-county Buhweju District. The study was guided by four specific objectives including an analysis of the social economic characteristics of farmers; identifying the constraints faced during tea growing; determining the impact of fertilizers on profitability of tea and the effect of inorganic fertilizers on growth and yields of tea. The goal of applying fertilizers is to provide crops with nutrients like potassium, phosphorus, and nitrogen, which allow crops to grow bigger, faster, and to produce more output. The study employed a case study research design with intention of providing in depth investigation of underling effect between the variables under study and both quantitative and qualitative data was employed. The study used purposive and random sampling methods hence using questionnaires and interview guides in collecting data. The study findings indicated that the major source of income among the respondents was subsistence farming (40%) and in relation to N, P, K fertilizer use, the majority of the farmers use it alongside organic fertilizers due to its high cost. While the major reasons as to why people would choose tea growing with fertilizers is that it increases on their yields hence increase in income. The study concluded that farmers should integrate in organic NPK fertilizer with organic fertilizers to achieve high yields with lower costs.

Evaluation of promising breeding apple varieties in Azerbaijan

The article discusses the creation of new varieties with high efficiency (in F1) using in the initial parent lines (in F2) in the creation of new varieties in the selection program of the plant flora of Azerbaijan, local, introduced varieties of fruit crops and selection of the Scientific-Research Institute of fruit growing and tea growing, the ripening period, yield, average mass of the final results are reported.

Effects of Shading Nets on Reactive Oxygen Species Accumulation, Photosynthetic Changes, and Associated Physiochemical Attributes in Promoting Cold-Induced Damage in Camellia sinensis (L.) Kuntze

Climate change and extreme weather affect tea growing. A competitive tea market needs quick, short-term solutions. This study evaluates the effects of various shade nets under mild and extreme cold stress on tea leaf physiology, photosynthetic alterations, antioxidant activities, and physiochemical characteristics. Tea plants were treated with SD0 (0% non-shading), SD1 (30% shading), SD2 (60% shading), and SD3 (75% shading). The 30%, 60%, and 75% shade nets shielded tea leaves from cold damage and reduced leaf injury during mild and extreme cold conditions compared with SD0% non-shading. Shading regulates photochemical capacity and efficiency and optimizes chlorophyll a and b, chlorophyll, and carotenoid contents. Moreover, carbon and nitrogen increased during mild cold and decreased in extreme cold conditions. Shading promoted antioxidant activity and physiochemical attributes. In fact, under 60% of shade, superoxide dismutase, peroxidase, catalase, and ω-3 alpha-linolenic acid were improved compared with SD0% non-shading during both mild and extreme cold conditions. From these findings, we hypothesized that the effect of different shades played an important role in the protection of tea leaves and alleviated the defense mechanism for “Zhong Cha 102” during exposure to a cold environment.

Dissipation behavior, residue transfer, and safety evaluation of chlorantraniliprole and indoxacarb during tea growing and brewing by ultrahigh-performance liquid chromatography-tandem mass spectrometry.

A reliable and simple analytical method was developed and validated to simultaneously determine chlorantraniliprole and indoxacarb in tea using ultrahigh-performance liquid chromatography-tandem mass spectrometry. The average recoveries of chlorantraniliprole were in the range of 86-110%, with the precision of intraday (n = 5) and interday (n = 15) ranging from 1.9 to 8.4% and from 2.4 to 8.8%, respectively. The average recoveries of indoxacarb were in the range 81-105%, with the precision of intraday (n = 5) and interday (n = 15) ranging from 2.0 to 9.8% and from 2.7 to 9.1%, respectively. The limits of quantification (LOQs) were all 0.01mg/kg. The results based on the supervised field trials showed that chlorantraniliprole and indoxacarb in two tea samples followed first-order kinetics models with half-lives of 2.2-4.7days and 2.5-3.5days, which could be regarded as a moderately degrading pesticide. The terminal residues of chlorantraniliprole and indoxacarb in made tea were below 6.7 and 4.5mg/kg, respectively, lower than their corresponding maximum residue limits (MRLs) established by several major countries and organizations (50 and 5mg/kg). The leaching rates of chlorantraniliprole and indoxacarb during the tea brewing ranged from 4.78 to 12.62% and 4.13 to 10.67%, respectively. The chronic intake risk quotient (RQc) values for chlorantraniliprole and indoxacarb were 0.24% and 35.10%, while the acute dietary risk assessment (RQa) value of indoxacarb was 5.8%, which were all much lower than 100%. The results in the present study indicated that the health risk posed by the chlorantraniliprole and indoxacarb mixture pesticides was negligible in tea for consumers at the recommended dosages.

Optimizing the Quality and Commercial Value of Gyokuro-Styled Green Tea Grown in Australia

Gyokuro is a style of Japanese green tea produced by employing agricultural shading in the weeks before harvest. This method results in a tea product with different organoleptic and chemical properties than common Japanese green tea. In an effort to yield the highest quality and commercially valuable green tea product, the present study explores the influence of shading treatments and the duration of shading on the natural biochemistry of the green tea plant. This study applied shading treatments at light intensity conditions of 40%, 16%, 10% and 1% of available ambient light and the application of a red-colored shade cloth of 60% opacity. The Quality Index Tool was used to measure the quality and commercial value of the green tea, using individual target constituents (theanine, caffeine and the catechins) quantified from HPLC analysis. This study shows that very high levels of total visible spectrum light shading (~99%) is required to achieve improvements in quality and commercial value. Specifically, this improvement is a direct result of changes in the mood- modifying bioactive metabolites theanine and caffeine. This study concludes that in green tea growing regions with more hours of sunlight per year, such as on the Central Coast of Australia, more intense shading will achieve products with improved quality and commercial value, which has more potential to be marketed as a functional ingredient.

A Short Verification of the Quality of Irrigation Water in the Tea-growing Districts of South India

Background: Variations in climatic conditions, irrigation facility and insect/pest management have brought about a massive impact on tea production. Among these the quality of the irrigation water and atmosphere related uncertainties were minimizing the tea production in right quantity and quality. The water utilized for irrigation systems can vary in quality depending on the nature and amount of dissolved salts. Minerals get dissolved into the irrigation water from various sources. They start from the disintegration of the stones and soil, including the decay of lime, gypsum and others broken up soil minerals. Salts go along with the water to the place wherever it is to being utilized. On account of the evaporation and filtration by sand particles, the salts present in the irrigation water get concentrated when the crop consumes water. Methods: Quality of the irrigation water was checked by assessing the pH, electrical conductivity, cations (Na+, K+, Mg2+, Ca2+) and anions (Cl-, HCO3-, CO32-). For evaluating the irrigation water quality and there are seven irrigation water samples collected from seven tea planting districts (Valparai- Tamil Nadu, Coonoor - Tamil Nadu, Gudalur - Tamil Nadu, Wayanad - Kerala, Munnar - Kerala, Vandiperiyar - Kerala, Koppa - Karnataka) in the southern states of India. Result: After evaluations of water quality from various techniques indicated that the water in tea growing locations of the southern states of India is chemically sufficient for agricultural applications.

Residue behavior, transfer and risk assessment of tolfenpyrad, dinotefuran and its metabolites during tea growing and tea brewing.

Tolfenpyrad and dinotefuran are two representative pesticides used for pest control in tea gardens. Their application may bring about a potential risk to the health of consumers. Therefore, it is essential to investigate the residue behavior, transfer and risk assessment of tolfenpyrad, dinotefuran and metabolites from tea garden to teacup. An effective analytical method was established and validated to simultaneously determine tolfenpyrad, dinotefuran and its metabolites (DN and UF) in tea. The average recoveries of tolfenpyrad, dinotefuran, DN and UF were in the range 72.1-106.3%, with relative standard deviations lower than 11.8%. On the basis of the proposed method, the dissipation of tolfenpyrad and dinotefuran in fresh tea leaves followed first-order kinetics models with half-lives of 4.30-7.33 days and 4.65-5.50 days, respectively. With application amounts of 112.5-168.75 g a.i.ha-1 once or twice, the terminal residues of tolfenpyrad and total dinotefuran in green tea were lower than 19.6 and 7.13 mg kg-1 , respectively, and below their corresponding maximum residue limits . The leaching rates of tolfenpyrad and total dinotefuran during the tea brewing were in the ranges 1.4-2.3% and 93.7-98.1%, respectively. Tolfenpyrad and dinotefuran in tea were easily degraded. The RQc and RQa values for tolfenpyrad were 37.6% and 5.4%, which were much higher than for dinotefuran at 24.7% and 0.84%, respectively. The data indicated that there was no significant health risk in tea for consumers at the recommended dosages. The results provide scientific data regarding the reasonable use of tolfenpyrad and dinotefuran aiming to ensure safe tea consuption. © 2021 Society of Chemical Industry.

Assessment of Constraints and Opportunities of Tea Out-Growers in South West Ethiopia

Tea, in Ethiopia, is grown in south west parts of the country. It is produced by estates namely Ethio Agri Ceft, East Africa PLC and other newly established tea plantations. They tried to cover the capacity of their processing factory by out growers surrounding tea plantations. Problems the out growers faced and opportunities they have not yet studied in detail. Therefore, this research attempted to generate useful information on tea out growers’ constraints and opportunities in tea production and marketing, which helps governmental institutions to assess their activities and redesign their operations. The research was done by interviewing tea out growers surrounding the two major tea plantations namely WushWush and Gumero in south west Ethiopia. Data was analyzed using descriptive statistics and constraints were analyzed using Relative Severity Index techniques. The data was collected from 120 randomly selected households surrounding the two major tea plantations. The result showed that out growers on average has experience of five years and allocated 1.37 ha of land to produce tea. Tea is among the most fertilizer and labor intensive crop of all the plantation crops. They plucked on average 295 kg/ha export standard or 731 kg/ha lowquality standard green tea leaves in one harvest in the main season. Relative Severity index analysis revealed that out growers’ major constraints of tea production were high price and not timely availability of inputs, shortage of inputs, high cost of production, need intensive plot management, lack of capital, no government extension service and lack of training. However, they have good opportunities in obtaining frequent income almost throughout the year, high cash income, low risk of animal damage and theft. This study concluded that out growers allocated 33% of total land owned to grow tea. Plucking was the main cost in tea production which took 30% of income from green tea leaves. On average, out growers obtained 2600 kg/ha/year green leaves which was much below the two tea plantations 3500 kg/ha/year. One of the main constraints of tea growing was high cost of production. However, they were benefited more from getting year round cash income, low risk of theft and animal damage.

The endangered African Great Ape: Pesticide residues in soil and plants consumed by Mountain Gorillas (Gorilla beringei) in Bwindi Impenetrable National Park, East Africa

Bwindi Impenetrable National Park situated southwest of Uganda is a biodiversity hotspot that is home to about half of the world's endangered mountain gorilla (Gorilla beringei). Given its ecological significance and mounting pressures from agricultural activities such as tea growing, continuous monitoring of the levels of chemical toxins like pesticides in the park and surrounding areas is needed for effective conservation strategies. Furthermore, persistent organochlorine pesticides (OCPs) like DDT were used in agricultural gardens and indoor spraying in Kanungu district between the 1950s and 80s. The focus of this study was to explore the possible exposure of mountain gorillas to OCPs and cypermethrin used by the farmers in the areas near the park. Data from our interviews revealed that glyphosate is the most widely used pesticide by the farmers in areas surrounding the park, followed by cypermethrin, and mancozeb. Samples of leaves from plants consumed by mountain gorillas along the forest edges of the park and surficial soils (15–20 cm depths) were collected from three sites (Ruhija, Nkuringo and Buhoma) and analysed for the presence of cypermethrin and OCPs residues. Concentrations of total (∑) DDTs and ∑endosulfans were up to 0.34 and 9.89 mg/kg dry weight (d.w), respectively in soil samples. Concentrations of ∑DDTs and ∑endosulfans in samples of leaves ranged from 0.67 to 1.38 mg/kg d.w (mean = 1.07 mg/kg d.w) and 0.9 to 2.71 mg/kg d.w (mean = 1.68 mg/kg d.w), respectively. Mean concentration of ∑DDTs in leaves exceeded the European pharmacopeia and United States pharmacopeia recommended maximum residue limit values for DDTs in medicinal plants (1.0 mg/kg). In addition, calculated hazard indices for silverbacks (36.35), females (57.54) and juveniles (77.04) suggested potential health risks to the mountain gorillas. o,p′-DDT/p,p′-DDT ratios (0.5–0.63) in samples of leaves confirmed recent input of dicofol-DDT type in Bwindi rainforest.

Residue dissipation, transfer and safety evaluation of picoxystrobin during tea growing and brewing.

Picoxystrobin is a new osmotic and systemic broad-spectrum methoxyacrylate fungicide with a good control effect on tea anthracnose, so it has been proposed to spray picoxystrobin before the occurrence and onset of tea anthracnose during tea bud growth in order to protect them. However, there are few reports about the residue analysis method, field dissipation, terminal residue and risk assessment of picoxystrobin in tea. And there is no scientific and reasonable maximum residue limit of picoxystrobin in green tea. A rapid and sensitive analysis method for picoxystrobin residue in fresh tea leaf, green tea, tea infusion and soil was established by UPLC-MS/MS. The spiked recoveries of picoxystrobin ranged from 73.1% to 111.0%, with relative standard deviations from 1.8% to 9.2%. The limits of quantitation were 20 μg kg-1 in green tea, 8 μg kg-1 in fresh tea leaves and soil and 0.16 μg kg-1 in tea infusion. The dissipation half-lives of picoxystrobin in fresh tea leaf and soil were 2.7-6.8 and 2.5-14.4 days, respectively. And the maximum residue of picoxystrobin in green tea was 15.28 mg kg-1 with PHI at 10 days for terminal test. The total leaching rate of picoxystrobin during green tea brewing was lower than 35.8%. According to safety evaluation, the RQc and RQa values of picoxystrobin in tea after 5 to 14 days for the last application were significantly lower than 1. Therefore, the maximum residue limit value of picoxystrobin in tea that we suggest to set at 20 mg kg-1 can ensure the safety of tea for human drinking. © 2020 Society of Chemical Industry.

Evaluation of biodiesel produced from tea seed oil in terms of fatty acid components

Factors such as increased energy demand, environmental pollution, energy security and ensuring energy sustainability have accelerated the search for alternative energy. The interest in renewable energy sources has increased with the decrease of oil, oil crises and the increase of environmental awareness. Biodiesel is an alternative energy source that is renewable with chemical methods from vegetable and animal oils. It does not cause CO₂ release and greenhouse effect compared to petro diesel. It is an environmentally friendly fuel. The tea seeds used in this study have been selected as an alternative from the idle tea seed for biodiesel production without harming the cooking oil stock in Turkey, which is an agricultural country where tea growing and tea consumption is increasing. Biodiesel production was investigated with the transesterification method, which is a method that reduces the production cost and viscosity of the oil obtained from tea seeds by using less chemicals to bring the idle tea seeds to the economy in Turkey and in the world.

Relationship between Environmental Covariates and Ceylon Tea Cultivation in Sri Lanka

How the current distribution of tea cultivation is influenced by specific environmental conditions in Sri Lanka is yet to be explored. Therefore, this study aims to assess the differences between tea and non-tea growing areas with respect to climatic and topographic covariates, and to determine the major covariates that control tea distributions. Climatic data of temperature and rainfall were extracted from WorldClim-Global Climate Data; the elevation, slopes, and aspects were obtained from Global Multi-resolution Terrain Elevation Data; and the solar radiation data was computed using a clear-sky solar radiation model. Random points were created on rasterised environmental layers for tea-growing and non-tea growing areas, stratified into low, mid, and high regions, using ArcGIS version 10.4.1 (Environmental Systems Research Institute: ESRI Redlands, CA, USA).Correlations were derived between covariates and tea and non-tea growing areas. According to the logistic regression analysis, there was no significant influence of the south-west, west, and north-west aspect compared to the north aspect when all other covariates were held constant. The odds ratio indicated that an area with a one-unit higher solar radiation was 1.453 times more likely to be a tea growing area. Similarly, a per unit increase in slope increases the likelihood of an area being suitable for tea cultivation by 1.039 times. When the annual mean temperature increased, the suitability of tea cultivation decreased, but an increased rainfall had increased the suitability of an area for tea cultivation. Areas with a north facing slope had the highest suitability for tea cultivation. This research demonstrated that tea growing could be expanded into a variety of locations as long as these variables are either found or managed in order to obtain the critical levels. In addition, it is proposed that the results of this study could be utilised in the assessment of the climate or/and land suitability for tea.

Perspective mutant forms of tea plants (Camellia sinensis (L.) Kuntze) in the collection of Russian Research Institute of Floriculture and Subtropical Crops

The article presents long-term data on the study of yield, biochemical parameters (tannin and extractive substances) and quality of tea raw materials (by the average mass of three-leaf fl ushes) of perspective mutant induced forms of tea breeding by Georgian scientists: 582 (radio mutant – aneuploid 2n = 36); 2264 (сolchicine mutant – mixoploid 2n = 38); 3823 (radio mutant – myxoploid 2n = 42). Standard Kolkhida variety was chosen as a control. The collection was planted in 1986 in CJSC «Dagomyschay» and is administered by the Russian Research Institute of Floriculture and Subtropical Crops. Vegetation of radio-mutant forms proceeded more actively, adaptability to summer drought was quite pronounced. By productivity, the following radiomutant forms can be distinguished: 582 (49.8 kg / ha) and 3823 (55.2 center/ha), with an excess over the control variety Kolkhida on 13.4-25.7 %. To a greater extent, the colchimutant form 2264 (30.2 C/ha) was inferior to the control, the credible diff erence was 31.2 %. In terms of the average weight of three-leaf fl ushes, the advantage was also in the mutant forms, it is 1.0 g and 0.96 g for the forms 3823 and 582, respectively, in the control variety the average weight was 0.89 g. It should be noting that the average mass of 3-leaf fl ushes was 0.4 g on the commercial plantations fi lled with local tea population. The biochemical parameters on tannin and extractive substances showed highest quality of fresh leaf yield of all mutant forms. At the same time, on this position, the mutant form 582 dominated, the tannin parameters exceeded the control variety Kolkhida by 2.6 %, the presence of extractive substances by 0.9 % (the infusion was moreintense). All the studying induced mutant tea forms represent practical interest for gene pool replenishment, breeding and implementation in commercial tea growing.

Diverse Metabolite Variations in Tea (Camellia sinensis L.) Leaves Grown Under Various Shade Conditions Revisited: A Metabolomics Study.

With the increase of tea (Camellia sinensis) consumption, its chemical or metabolite compositions play a crucial role in the determination of tea quality. In general, metabolite compositions of fresh tea leaves including shoots depend on plucking seasons and tea cultivators. Therefore, choosing a specific plucking time of tea leaves can provide use-specified tea products. Artificial control of tea growing, typically shade treatments, can lead to significant changes of the tea metabolite compositions. However, metabolic characteristics of tea grown under various shade treatment conditions remain unclear. Therefore, the objective of the current study was to explore effects of various shade conditions on metabolite compositions of tea through a 1H NMR-based metabolomics approach. It was noteworthy that the levels of catechins and their derivatives were only influenced at the initial time of shade treatments while most amino acids were upregulated as amounts of shade and periods were increased: that is, the levels of alanine, asparagine, aspartate, isoleucine, threonine, leucine, and valine in fresh tea leaves were conspicuously elevated when shade levels were raised from 90% to 100% and when period of shade treatments was increased by 20 days. Such increased synthesis of amino acids along with large reductions of glucose level reflected carbon starvation under the dark conditions, indicating remarkable proteolysis in the chloroplast of tea leaves. This study provides important information about making amino acid-enhanced tea products based on global characteristics of diverse tea leaf metabolites induced by various shade treatment conditions.

Spectrophotometric Analysis of Tooth Discoloration after Bracket Debonding Induced by Coffee and Tea Grown in South India: An In vitro Study

Aim: To evaluate the staining produced on dental enamel after bracket debonding on exposure to 2 different types of coffee and tea produced in South India. Materials and Methods: Fifty premolars extracted for orthodontic purposes were randomly assigned to five groups .Orthodontic brackets were placed and debonded on the test side. Tooth surfaces were exposed to 2 different types of coffee and tea and color changes were recorded with a spectrophotometer. Results: All solutions of coffee and tea produced statistically significant color changes in both the test and control group with more pronounced color changes in the test group. Conclusion: Scaling and polishing should be advised for all patients after bracket debonding to reduce the impact of staining on tooth surfaces.

Trouble is brewing for Assam tea

Cousins examines the trouble brewing in the plantations of Assam, the world's largest tea-growing region, famous for its strong breakfast tea. Assam has a hot, humid climate with temperatures already at the upper end of the optimum range for tea growing. As the climate warms, the tea crops here come under ever greater stress. This is compounded by changing rainfall patterns. Too little rain forces planters to use expensive sprinklers or irrigation pipes to get better yields. The drier climate is also more conducive to pests such as the tea mosquito bug. These invaders eat the foliage and make plants more vulnerable to disease, lowering the yield. The use of pesticides and fertilizers has gone up in turn, increasing both production costs and health risks.