Pub Date : 2017-04-28DOI: 10.5376/jtsr.2017.07.0004
B. Deka, A. Babu, M. Sarmah
Leaf extracts of five different locally available plants such as Polygonum hydropiper L. , Vitex negundo L , Tithonia diversifolia (Hemsl.) (wild sun flower), Artemisia vulgaris L and Clerodendrum infortunatum L were evaluated for their ovicidal and acaricidal activity against the tea red spider mite, Oligonychus coffeae , Nietner (Tetranychidae: Acarina) in the laboratory using the leaf disc method under controlled conditions. Leaves collected from the above mentioned plants were dried under shade, milled in an electric blender and extracted using two different solvents, hexane and methanol and prepared different concentrations viz. 1%, 0.75%, 0.50% and 0.25% by diluting in DMSO (dimethyl sulfoxide; an important polar solvent) and were used for different bioassays. The effects of the extracts on the mortality of adults as well as in the eggs were assessed after spraying and the results were compared with an untreated control. All tested plants showed varying levels of efficacy on red spider mite compared when with the untreated control. Among five plant species tested, methanol extract of Vitex negundo and Clerodendrum infortunatum showed maximum ovicidal action (66.71% and 57.45% respectively) and exhibited more than 90% adult mortality @ 1% conc. of both the hexane and methanol extract of Vitex negundo and Clerodendrum infortunatum after 24 h.
{"title":"Bio-efficacy of Certain Indigenous Plant Extracts against Red Spider Mite, Oligonychus coffeae , Nietner (Tetranychidae: Acarina) Infesting Tea","authors":"B. Deka, A. Babu, M. Sarmah","doi":"10.5376/jtsr.2017.07.0004","DOIUrl":"https://doi.org/10.5376/jtsr.2017.07.0004","url":null,"abstract":"Leaf extracts of five different locally available plants such as Polygonum hydropiper L. , Vitex negundo L , Tithonia diversifolia (Hemsl.) (wild sun flower), Artemisia vulgaris L and Clerodendrum infortunatum L were evaluated for their ovicidal and acaricidal activity against the tea red spider mite, Oligonychus coffeae , Nietner (Tetranychidae: Acarina) in the laboratory using the leaf disc method under controlled conditions. Leaves collected from the above mentioned plants were dried under shade, milled in an electric blender and extracted using two different solvents, hexane and methanol and prepared different concentrations viz. 1%, 0.75%, 0.50% and 0.25% by diluting in DMSO (dimethyl sulfoxide; an important polar solvent) and were used for different bioassays. The effects of the extracts on the mortality of adults as well as in the eggs were assessed after spraying and the results were compared with an untreated control. All tested plants showed varying levels of efficacy on red spider mite compared when with the untreated control. Among five plant species tested, methanol extract of Vitex negundo and Clerodendrum infortunatum showed maximum ovicidal action (66.71% and 57.45% respectively) and exhibited more than 90% adult mortality @ 1% conc. of both the hexane and methanol extract of Vitex negundo and Clerodendrum infortunatum after 24 h.","PeriodicalId":17156,"journal":{"name":"Journal of Tea Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77942623","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}
Pub Date : 2017-04-20DOI: 10.5376/jtsr.2017.07.0005
A. Laskar, C. Paul, B. Laskar
Pharmacological values of tea have been found by medical researchers in many countries. Catechin compounds found in tea impart several health benefits including mitigating dental ailments. However, whether dento-clinical properties of catechins are camouflaged by additive like milk or not has remained unexplored. A survey-based study involving community people suffering from gum disease (gingivitis) has been carried out to understand whether hot water extract of tea ( known as brew) without milk has any relevance in reducing gingivitis. The survey reveals a strong negative linear correlation ( r= -0.807** ) between drinking tea without milk and reduction of gingivitis. The results also reveal that frequency of gingivitis amongst people who drink tea with milk is more ( r= 0.696* ) as compared to the people who drink tea without milk. Tea made from Tinali 17/1/54 cultivar of Camelia sinensis L. O. Kuntze var, Assamica has been used in the study as this cultivar is ubiquitous in tea growing areas and can produce different categories of black tea – strong CTC tea, mild flavored orthodox tea and milder green tea.
茶的药理价值已被许多国家的医学研究者发现。茶中发现的儿茶素化合物具有多种健康益处，包括减轻牙齿疾病。然而，儿茶素的牙齿-临床特性是否被添加剂如牛奶所掩盖仍未被研究。一项基于调查的研究涉及患有牙龈疾病(牙龈炎)的社区人群，以了解不加牛奶的热水茶提取物(称为冲泡茶)是否与减少牙龈炎有关。调查显示，喝茶不加牛奶与减少牙龈炎之间存在很强的负线性相关(r= -0.807**)。结果还显示，与不喝牛奶的人相比，喝牛奶茶的人患牙龈炎的频率更高(r= 0.696*)。由于该品种在茶叶种植区普遍存在，可以生产出不同种类的红茶——浓郁的CTC茶、温和的正统茶和温和的绿茶，因此研究中使用的是Tinali 17/1/54茶树品种Kuntze var, Assamica。
{"title":"Effect of Tea on Gingivits: A Community-based Study","authors":"A. Laskar, C. Paul, B. Laskar","doi":"10.5376/jtsr.2017.07.0005","DOIUrl":"https://doi.org/10.5376/jtsr.2017.07.0005","url":null,"abstract":"Pharmacological values of tea have been found by medical researchers in many countries. Catechin compounds found in tea impart several health benefits including mitigating dental ailments. However, whether dento-clinical properties of catechins are camouflaged by additive like milk or not has remained unexplored. A survey-based study involving community people suffering from gum disease (gingivitis) has been carried out to understand whether hot water extract of tea ( known as brew) without milk has any relevance in reducing gingivitis. The survey reveals a strong negative linear correlation ( r= -0.807** ) between drinking tea without milk and reduction of gingivitis. The results also reveal that frequency of gingivitis amongst people who drink tea with milk is more ( r= 0.696* ) as compared to the people who drink tea without milk. Tea made from Tinali 17/1/54 cultivar of Camelia sinensis L. O. Kuntze var, Assamica has been used in the study as this cultivar is ubiquitous in tea growing areas and can produce different categories of black tea – strong CTC tea, mild flavored orthodox tea and milder green tea.","PeriodicalId":17156,"journal":{"name":"Journal of Tea Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78757414","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}
Pub Date : 2017-03-20DOI: 10.5376/jtsr.2017.07.0003
W. Omwoyo, Olunga Sween, S. Kibet, F. Oloo
Tea yields peak is 21-30 years after which yields decline. The declining productivity and moribuncy has been reported in many tea fields due to prolonged period of monoculture under tea, physicochemical and biological properties of soil deteriorate considerably causing diseases, pests, acidic soils among others which leads to uprooting of old tea bushes. Deficiency of micronutrients in some tea sections has been reported which has been corrected by foliar application. Though the deficiency could be corrected through foliar application, this mode of application has its shortcomings including leaf burn and the mobility of nutrients from the leaves to the roots is very slow. This study aimed at determining the effect of soil application and variation of micronutrients on the nutritional status of clonal tea replanted in old tea lands.Leaf and soil samples were collected in a random complete block design and the micromutrient levels determined using Inductively Coupled Plasma Emission (ICPE). Data analysis was done using MSTAT-C software.The changes in the levels of micronutrients with varied eight micronutrient combinations subjected on different clones were studied. Clone 12/28 significantly (P≤0.05) varied with the other clones indicating that different clones have varied abilities to absorb nutrients. Clone 303/577 gave a significantly higher uptake of B in the order TRFK303/577 >S15/10 >12/28 >31/8. Clone 12/28 recorded a higher uptake of N with mean levels of 3.075, clone 31/8 had significantly higher uptakes of Fe and Zn. None of the micronutrients subjected on the clones brought an impact in the uptake of N and Mg. This study therefore recommends the use of soil application of micronutrients as an alternative to foliar application in areas where old tea bushes were uprooted.
{"title":"Effects of Micronutrients on the Nutritional Status of Clonal Tea Replanted in Areas Where Old Tea Was Uprooted","authors":"W. Omwoyo, Olunga Sween, S. Kibet, F. Oloo","doi":"10.5376/jtsr.2017.07.0003","DOIUrl":"https://doi.org/10.5376/jtsr.2017.07.0003","url":null,"abstract":"Tea yields peak is 21-30 years after which yields decline. The declining productivity and moribuncy has been reported in many tea fields due to prolonged period of monoculture under tea, physicochemical and biological properties of soil deteriorate considerably causing diseases, pests, acidic soils among others which leads to uprooting of old tea bushes. Deficiency of micronutrients in some tea sections has been reported which has been corrected by foliar application. Though the deficiency could be corrected through foliar application, this mode of application has its shortcomings including leaf burn and the mobility of nutrients from the leaves to the roots is very slow. This study aimed at determining the effect of soil application and variation of micronutrients on the nutritional status of clonal tea replanted in old tea lands.Leaf and soil samples were collected in a random complete block design and the micromutrient levels determined using Inductively Coupled Plasma Emission (ICPE). Data analysis was done using MSTAT-C software.The changes in the levels of micronutrients with varied eight micronutrient combinations subjected on different clones were studied. Clone 12/28 significantly (P≤0.05) varied with the other clones indicating that different clones have varied abilities to absorb nutrients. Clone 303/577 gave a significantly higher uptake of B in the order TRFK303/577 >S15/10 >12/28 >31/8. Clone 12/28 recorded a higher uptake of N with mean levels of 3.075, clone 31/8 had significantly higher uptakes of Fe and Zn. None of the micronutrients subjected on the clones brought an impact in the uptake of N and Mg. This study therefore recommends the use of soil application of micronutrients as an alternative to foliar application in areas where old tea bushes were uprooted.","PeriodicalId":17156,"journal":{"name":"Journal of Tea Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84135805","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}
Pub Date : 2017-03-03DOI: 10.5376/JTSR.2017.07.0002
S. R. Sarmah, P. K. Baruah, S. Das
In Northeast Indian tea plantations infection of Fusaruim solani , resulting dieback of tea plant is increasing which causes considerable crop loss during the recent times. In this investigation, native plant extracts, i.e. Acorus calamus L., Azadirachta indica A. Juss., Clerodendrum viscosum Vent., and Xanthium strumarium L. and microbials i.e. Bacillus subtilis and Trichoderma viride Pers. were utilized to evaluate the efficacy in controlling dieback disease of tea. These extracts inhibited the growth of Fusarium solani by 60-90%. In field application of C. viscosum and X. strumarium extracts reduced the disease up to 89.3% and 81% respectively. More than 70% disease reduction was observed when aqueous extracts of A. calamus and A. indica were used separately. Maximum disease reduction was achieved up to 86.9% due to application of T. viride . The results, thus, suggested the potential use of herbal extracts and microbial strains as an effective component of integrated disease management (IDM) schedule in the organic tea farming. The methods and rate of application are also discussed.
{"title":"Practical Utilization of Botanical Extracts and Microbial in Controlling Dieback Disease of Tea [ Camellia sinensis (L) O. Kuntze] Caused by Fusarium solani (Mart.) Sacc.","authors":"S. R. Sarmah, P. K. Baruah, S. Das","doi":"10.5376/JTSR.2017.07.0002","DOIUrl":"https://doi.org/10.5376/JTSR.2017.07.0002","url":null,"abstract":"In Northeast Indian tea plantations infection of Fusaruim solani , resulting dieback of tea plant is increasing which causes considerable crop loss during the recent times. In this investigation, native plant extracts, i.e. Acorus calamus L., Azadirachta indica A. Juss., Clerodendrum viscosum Vent., and Xanthium strumarium L. and microbials i.e. Bacillus subtilis and Trichoderma viride Pers. were utilized to evaluate the efficacy in controlling dieback disease of tea. These extracts inhibited the growth of Fusarium solani by 60-90%. In field application of C. viscosum and X. strumarium extracts reduced the disease up to 89.3% and 81% respectively. More than 70% disease reduction was observed when aqueous extracts of A. calamus and A. indica were used separately. Maximum disease reduction was achieved up to 86.9% due to application of T. viride . The results, thus, suggested the potential use of herbal extracts and microbial strains as an effective component of integrated disease management (IDM) schedule in the organic tea farming. The methods and rate of application are also discussed.","PeriodicalId":17156,"journal":{"name":"Journal of Tea Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77122055","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}
Pub Date : 2017-02-06DOI: 10.5376/JTSR.2017.07.0001
W. Omwoyo
Micronutrients are important to both the human life and the tea plant. Camellia sinensis is widely grown in East Africa and its beverages are claimed to be the most widely consumed fluids after water. The changes in the levels of micronutrients with varied rates of nitrogenous fertilizer and plucking intervals three different locations were studied. All the studied micronutrients significantly (p≤0.05) varied with location of production. Mn and Se levels did not significantly (p≤0.05) change with an increase in nitrogenous fertilizer rates. Fe and Zn significantly (p≤0.05) increased with an increase in nitrogen fertilizer rates while Cu significantly (p≤0.05). The micronutrient content of the black teas did not significantly (p≤0.05) change with varied plucking intervals. There is need to strike a balance in the application of nitrogenous fertilizer rates in different locations in order to harmonize all the micronutrients. This research recommends 150 kg/ha/year of nitrogenous fertilizer rate that will strike a balance on all the studied micronutrients.
{"title":"Effects of Nitrogenous Fertilizer Rates, Plucking Intervals and Geographical Location of Production on Selected Micronutrient Levels of the Black Tea","authors":"W. Omwoyo","doi":"10.5376/JTSR.2017.07.0001","DOIUrl":"https://doi.org/10.5376/JTSR.2017.07.0001","url":null,"abstract":"Micronutrients are important to both the human life and the tea plant. Camellia sinensis is widely grown in East Africa and its beverages are claimed to be the most widely consumed fluids after water. The changes in the levels of micronutrients with varied rates of nitrogenous fertilizer and plucking intervals three different locations were studied. All the studied micronutrients significantly (p≤0.05) varied with location of production. Mn and Se levels did not significantly (p≤0.05) change with an increase in nitrogenous fertilizer rates. Fe and Zn significantly (p≤0.05) increased with an increase in nitrogen fertilizer rates while Cu significantly (p≤0.05). The micronutrient content of the black teas did not significantly (p≤0.05) change with varied plucking intervals. There is need to strike a balance in the application of nitrogenous fertilizer rates in different locations in order to harmonize all the micronutrients. This research recommends 150 kg/ha/year of nitrogenous fertilizer rate that will strike a balance on all the studied micronutrients.","PeriodicalId":17156,"journal":{"name":"Journal of Tea Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85073164","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}
Pub Date : 2016-12-27DOI: 10.5376/JTSR.2016.06.0010
Pandian Kumar, C. Sundaravadivelan, D. V. Kumar, A. Babu
Tea ( Camellia sinensis ) is one of the most consumed non-alcoholic beverages in the world and has been affected by many pests which damage its quality and production globally. In this paper an attempt has been made to evaluate the aqueous leaf extracts of Senna auriculata and Ocimum tenuiflorum with and without adjuvant for their effect on red spider mite (RSM), Oligonychus coffeae (Nietner) infesting tea. Resulting, Senna auriculata, leaf extracts with adjuvant caused 90 % (LC 50 :1.21 and LC 90 :2.33 %) mortality which was greater compared to Ocimum tenuiflorum whereas 73 % (LC 50 :1.40 and LC 90 :2.81 %) was observed at 5 % concentration after 24 h exposure and very lowest mortality percent were observed both extracts without adjuvant. Ocimum tenuiflorum leaf extracts with adjuvant (0.05 %) showed highest ovicidal activity and effective ovipositional deterrence compared with S. auriculata treatment. The evaluated plant extracts with adjuvant are effective for controlling RSM and it could be an alternative, easily accessible, and eco-friendly approach for control of mite infesting tea.
{"title":"Enhanced Acaricidal Activity of Senna auriculata and Ocimum tenuiflorum Extracts with the Addition of Adjuvant against Red Spider Mite, Oligonychus coffeae Nietner (Acarina: Tetranychidae) Infesting Tea","authors":"Pandian Kumar, C. Sundaravadivelan, D. V. Kumar, A. Babu","doi":"10.5376/JTSR.2016.06.0010","DOIUrl":"https://doi.org/10.5376/JTSR.2016.06.0010","url":null,"abstract":"Tea ( Camellia sinensis ) is one of the most consumed non-alcoholic beverages in the world and has been affected by many pests which damage its quality and production globally. In this paper an attempt has been made to evaluate the aqueous leaf extracts of Senna auriculata and Ocimum tenuiflorum with and without adjuvant for their effect on red spider mite (RSM), Oligonychus coffeae (Nietner) infesting tea. Resulting, Senna auriculata, leaf extracts with adjuvant caused 90 % (LC 50 :1.21 and LC 90 :2.33 %) mortality which was greater compared to Ocimum tenuiflorum whereas 73 % (LC 50 :1.40 and LC 90 :2.81 %) was observed at 5 % concentration after 24 h exposure and very lowest mortality percent were observed both extracts without adjuvant. Ocimum tenuiflorum leaf extracts with adjuvant (0.05 %) showed highest ovicidal activity and effective ovipositional deterrence compared with S. auriculata treatment. The evaluated plant extracts with adjuvant are effective for controlling RSM and it could be an alternative, easily accessible, and eco-friendly approach for control of mite infesting tea.","PeriodicalId":17156,"journal":{"name":"Journal of Tea Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75501065","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}
Pub Date : 2016-12-22DOI: 10.5376/JTSR.2016.06.0009
Hoque A.K.M.R., Aslam A.F.M., M. Ahmed, Mamun M.S.A., A. Howlader
Experiments were carried out to determine bioefficacy of an entomopathogenic fungus formulation - Bioterminator ( Metarhizium anisopliae ) against termites infesting tea during February, 2015 to October 2015. The experiment was performed in both laboratory and the field conditions. In the laboratory experiment, mortality data were recorded daily up to 7 days after treatment (DAT) and at monthly interval for field experiments. Result revealed from the laboratory bioassay that Bio-terminator was found to be effective (43.28-72.94%) up to 7 days after treatment. In field condition, Bio-Terminator was found to be highly effective (85.21, 84.91 & 85.97% respectively) in controlling termites and maintain their effectiveness to the desired level up to 9 months. Therefore, Bio-terminator may be efficiently used for the management of termites in tea as the component of Integrated Pest Management.
{"title":"Laboratory and Field Evaluation of an Entomopathogenic Fungus Formulation-Bioterminator (Metarhizium Anisopliae Metchnikoff) against Termite Infesting Tea","authors":"Hoque A.K.M.R., Aslam A.F.M., M. Ahmed, Mamun M.S.A., A. Howlader","doi":"10.5376/JTSR.2016.06.0009","DOIUrl":"https://doi.org/10.5376/JTSR.2016.06.0009","url":null,"abstract":"Experiments were carried out to determine bioefficacy of an entomopathogenic fungus formulation - Bioterminator ( Metarhizium anisopliae ) against termites infesting tea during February, 2015 to October 2015. The experiment was performed in both laboratory and the field conditions. In the laboratory experiment, mortality data were recorded daily up to 7 days after treatment (DAT) and at monthly interval for field experiments. Result revealed from the laboratory bioassay that Bio-terminator was found to be effective (43.28-72.94%) up to 7 days after treatment. In field condition, Bio-Terminator was found to be highly effective (85.21, 84.91 & 85.97% respectively) in controlling termites and maintain their effectiveness to the desired level up to 9 months. Therefore, Bio-terminator may be efficiently used for the management of termites in tea as the component of Integrated Pest Management.","PeriodicalId":17156,"journal":{"name":"Journal of Tea Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73660239","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}
Pub Date : 2016-10-24DOI: 10.5376/jtsr.2016.06.0008
D. Biswas
Daily rate of wages for tea plantation workers in west Bengal is abysmally low in comparison to agricultural minimum wages. There are a few benefits offered by the employers apart from the statutory benefits enshrined in the Plantation Labour Act, 1951. Consequently, many tea workers in this state are suffering from starvation, malnutrition, debt, etc. In this backdrop, in my present study, a deliberate attempt has been made in order to highlight the actual picture of wage and its determination process in the tea industry located in West Bengal in India.
{"title":"Wage determination machinery of tea industry in India: a case of West Bengal State","authors":"D. Biswas","doi":"10.5376/jtsr.2016.06.0008","DOIUrl":"https://doi.org/10.5376/jtsr.2016.06.0008","url":null,"abstract":"Daily rate of wages for tea plantation workers in west Bengal is abysmally low in comparison to agricultural minimum wages. There are a few benefits offered by the employers apart from the statutory benefits enshrined in the Plantation Labour Act, 1951. Consequently, many tea workers in this state are suffering from starvation, malnutrition, debt, etc. In this backdrop, in my present study, a deliberate attempt has been made in order to highlight the actual picture of wage and its determination process in the tea industry located in West Bengal in India.","PeriodicalId":17156,"journal":{"name":"Journal of Tea Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84606038","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}
Pub Date : 2016-04-15DOI: 10.20425/IJTS.V0IOF.9577
Toshio Hasegawa, Yasutsugu Tsukumo, Takashi Fujita, T. Fujihara, A. Takahashi, K. Nakajima
We previously reported the group of aroma constituents that characterize the odor of sencha (green tea made from leaves) which is similar to but distinct from the odor of commercially available matcha (Japanese green tea made from powder).This study, investigated whether the group of aroma compounds contributing to this matcha-like odor is present in all green tea cultivars and products. Crude sencha teas made from the 'Yabukita', 'Sayamakaori', 'Samidori', and 'Ujimidori' cultivars, and teas prepared by different processes (hojicha and unkacha), were investigated. These green tea leaves had a common matcha-like odor originating from a group of identical constituents. Commercially available matcha were studied as the source of the standard odor. The extracts obtained from matcha were separated into groups with different odors by fractional distillation. Chemical and analytical methods showed that the group of key compounds producing the matcha-like odor included a minute quantity of several aliphatic aldehydes. Many aldehyde proton signals were observed by 1H NMR and some aldehydes were detected by mass spectroscopy. It was concluded that a matcha-like odor that contained some aliphatic aldehydes was the base note of green tea leaves, indicating the importance of the matcha-like odor to green tea's odor character.
{"title":"The odor of matcha (Japanese powdered green tea) as the base note of green tea leaves","authors":"Toshio Hasegawa, Yasutsugu Tsukumo, Takashi Fujita, T. Fujihara, A. Takahashi, K. Nakajima","doi":"10.20425/IJTS.V0IOF.9577","DOIUrl":"https://doi.org/10.20425/IJTS.V0IOF.9577","url":null,"abstract":"We previously reported the group of aroma constituents that characterize the odor of sencha (green tea made from leaves) which is similar to but distinct from the odor of commercially available matcha (Japanese green tea made from powder).This study, investigated whether the group of aroma compounds contributing to this matcha-like odor is present in all green tea cultivars and products. Crude sencha teas made from the 'Yabukita', 'Sayamakaori', 'Samidori', and 'Ujimidori' cultivars, and teas prepared by different processes (hojicha and unkacha), were investigated. These green tea leaves had a common matcha-like odor originating from a group of identical constituents. Commercially available matcha were studied as the source of the standard odor. The extracts obtained from matcha were separated into groups with different odors by fractional distillation. Chemical and analytical methods showed that the group of key compounds producing the matcha-like odor included a minute quantity of several aliphatic aldehydes. Many aldehyde proton signals were observed by 1H NMR and some aldehydes were detected by mass spectroscopy. It was concluded that a matcha-like odor that contained some aliphatic aldehydes was the base note of green tea leaves, indicating the importance of the matcha-like odor to green tea's odor character.","PeriodicalId":17156,"journal":{"name":"Journal of Tea Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81094746","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}
Pub Date : 2016-04-15DOI: 10.20425/IJTS.V0IOF.9578
Yumnam Devashree, B. Dutta, S. Paul, Sudip Choudhury
An experiment was carried out in Rosekandy Tea Estate, Barak Valley, Assam to investigate the persistence of some selected pesticides (i.e Endosulfan, Fipronil, Paraquat and 2,4-D) on the soil. These pesticides were applied in the soil as per the application rate, where one year old tea plants were growing and the residue were analysed for a period of 50 days. Their degradation kinetics in soil was also studied and described. Soil samples were collected with the help of soil corer. The samples were brought to the laboratory, air dried in room temperature and extracted for analysis with high performance liquid chromatography (HPLC). Among the pesticides 2,4-D was highly persistent with half life of 57.75 days followed by Endosulfan which lost 42.64% of its initial concentration by the last sampling period (i.e 50 days) after the spraying. Fipronil and paraquat lost 65% and 70.32% of initial residue in soil making them the least persistent amongst these pesticides in the studied soil. Considering the impact of pesticide residues on human health, the less persistent pesticides may be used in tea plantations to minimize the potential negative impact of pesticides in the environment. The cost benefit ratios of the use of the pesticides should be also worked out.
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