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Moitra S.,Allergy and Asthma Research Center | Thapa P.,Darjeeling Tea Research and Development Center | Das P.,Allergy and Asthma Research Center | Das J.,Allergy and Asthma Research Center | And 4 more authors.
International Journal of Occupational and Environmental Medicine | Year: 2016

Background: Indian tea industry workers are exposed to various exposures at their workplace. Objective: To investigate the respiratory health of Indian tea industry workers. Methods: We administered a respiratory questionnaire to and measured lung function in workers of 34 tea gardens and 46 tea factories. We used correlation matrices to test the association between their respiratory symptoms and lung functions. Results: The garden workers complained of shortness of breath 3 times higher than the factory workers. However, nasal allergy was more predominant among the factory workers compared to garden workers (69.6% vs 41.2%, p=0.02). The factory workers had higher total (median 107.3% vs 92.9%, p=0.05, as measured by R at 5 Hz) and peripheral airway resistance (143.8% vs 61.1%, p=0.005, as measured by R at 5–20 Hz) than the garden workers. Respiratory symptoms were inversely associated with airway obstruction as measured by the ratio between forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) and positively correlated with increased overall airway reactance among the workers. Conclusion: Respiratory symptoms and increased allergen susceptibility of Indian tea industry workers due to occupational exposures warrant routine systematic surveillance of their workplace air quality and health monitoring. © 2016, NIOC Health Organization. All rights reserved.

Chandra S.,University of Calcutta | Chandra S.,Directorate of Research | Chakraborty N.,University of Calcutta | Chakraborty A.,Darjeeling Tea Research and Development Center | And 3 more authors.
Archives of Phytopathology and Plant Protection | Year: 2014

Tea, the second most consumed beverage after water in the world, is produced from the processed tender leaves of tea plants (Camellia sinensis). Production of tea is hindered by various biotic and abiotic stresses. Among the biotic factors, blister blight disease caused by an obligate fungal pathogen, Exobasidium vexans Massee, is a serious problem to the tea industry. The present study was to evaluate the efficacy of elicitor calcium chloride (CaCl2) in inducing resistance in tea plants against blister blight disease. During the pick time of blister incidence at Darjeeling tea garden, the application of CaCl2 at a concentration of 1% resulted in disease inhibition around 71% over the control set. Treatment also resulted in the induction of defence enzymes like peroxidase, polyphenol oxidase, phenylalanine ammonia lyase, β-1,3-glucanase and higher phenol accumulation. Furthermore, the increase in defence molecules also correlated with increase in nitric oxide (NO) generation, a potent defence molecule in plant defence. The result suggests that CaCl2 can used as a potential elicitor in the integrated disease management in organic tea cultivation. © 2014 © 2014 Taylor & Francis.

Ajay D.,UPASI Tea Research Institute | Ajay D.,Darjeeling Tea Research and Development Center | Baby U.I.,UPASI Tea Research Institute | Baby U.I.,SGS India P Ltd.
Phytoparasitica | Year: 2010

The effect of two chemical elicitors (acibenzolar-S-methyl benzo-[1,2,3]- thiadiazole-7-carboxylic acid S-methyl ester [Boost 500SC]) and salicylic acid in inducing resistance in tea plants against blister blight disease caused by Exobasidium vexans Massee, was studied. Treatments with elicitors resulted in reduced severity of blister blight disease in nursery plants on challenge with the pathogen. There was a significant increase in the activities of defense enzymes like phenylalanine ammonia lyase, peroxidase and β-1,3-glucanase on elicitor treatments in tea leaves challenged with the pathogen than on unchallenged leaves. Acibenzolar-S-methyl (ASM) at 0.14% registered the lowest disease severity (25.2%), whereas treatments with salicylic acid were inferior. Under field conditions, the application of ASM at 0.14% resulted in disease protection of 25%. When ASM was applied in alternate rounds with a standard fungicide, the disease protection improved to 46.8%. The importance of incorporating ASM as a component in integrated disease management and also its importance in organic tea cultivation is discussed. © Springer Science & Business Media B.V. 2009.

Bisen J.S.,Darjeeling Tea Research and Development Center | Singh A.K.,Darjeeling Tea Research and Development Center
Indian Journal of Horticulture | Year: 2012

Organic cultivation of tea has already started in India. Darjeeling tea has an edge in international and domestic markets. A study was undertaken to compare the traditional and organic cultivation in Darjeeling region in 21 gardens. Yield reduction was 10 to 21.2% during conversion period. In medium and low yielding gardens there was a reduction of upto 29%. However, the quality parameters were quite better with higher price realization.

Dasgupta N.,Indian Statistical Institute | Biswas P.,Darjeeling Tea Research and Development Center | Kumar R.,Darjeeling Tea Research and Development Center | Kumar N.,Darjeeling Tea Research and Development Center | And 2 more authors.
Physiology and Molecular Biology of Plants | Year: 2013

Ten Darjeeling tea clones (BT15/263, RR17/144, B777, T253, B157, Sundaram, HV39, AV2, K1/1 and TTV1) were collected from the experimental garden of Darjeeling Tea Research and Development Centre, Kurseong. Total phenol, flavonoids and two antioxidating enzymes (peroxidase and superoxide dismutase) were estimated. The total phenol ranged between 241 and 28 GAE mg g-1 of leaf dry weight. The highest amount obtained in four clones, B15/263 (241.47), RR17/144 (221.2), B777 (154.54) and B157 (140.23 mg g-1). Flavonoids were estimated as Catechin equivalent (CE) and ranged between 56.88 and 20.81 CE mg g-1 leaf dry weight. Higher amounts occurred in BT15/263 (56.88 mg g-1), B777 (56.69) and RR17/144 (48.63). Antioxidant activities were measured following DPPH and ABTS free radicle scavenging procedures and the results were well according to total polyphenol content among the clones (in total phenols, ranges of correlation in DPPH assay were r2 = 0.990-0.989, p ≤ 0.05; in flavonoids r2 = 0.954, p ≤ 0.01-0.987, p ≤ 0.05). Similarly, ABTS percent scavenging results were quiet significant. The IC50 values were determined for both DPPH and ABTS assay. PAGE expressions of isoforms in two antioxidative enzymes and quantification of them also varied much among the investigated clones. The incidence of total phenols, flavonoids, PRX and SOD and ROS scavenging assay in in-situ condition, might be used as biochemical markers towards the superior adaptability against abiotic stress. In the present work, four clones (B15/263, B777, RR17/144 and B157) would be designated as comparatively better suited to the predicted abiotic stress. © 2013 Prof. H.S. Srivastava Foundation for Science and Society.

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