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A. Plant Physiology, Breeding and Development

1. Investigations on the bio-chemical basis of rooting and clonal compatibility in nursery grafting of fresh cuttings in tea.

Salient findings:
Rooting: Superior and early rooting characteristics of the easy to root clones are associated with lower levels of total polyphenols,ortho dihbydroxy phenol, cate chins, total nitrogen content, indole acetic acid oxidase and higher levels of polyphenol oxidase, peroxidase, total protein, total carbon and carbon: nitrogen ratio in the units of propagation.
Compatibility between clones could be simplified on the basis of analysis of the levels of phenolic compounds and endogenous levels of polyphenol oxidase, peroxidase, indole acetic acid,total protein content, nitrogen, carbon and carbon: nitrogen ratio and the isoezyme profile such as polyphenol oxidase, peroxidase and indole acetic acid oxidase.

Benefits to the industry:
This study established that 5-6 compatible combinations of root stock and scion would enhance yield 20-25 %. This has been commercialized in South India.

2. Development of a protocol for efficient somaclonal plants using drought tolerant UPASI clones as source of explants.

Salient findings:

  • The protocol for somatic embryo induction in tea using cotyledonary explants was developed. Fine tuning of the finer aspects according to the variety, nature of the explants and time of collection are however needed.
  • Somaclonal plants with diversified morphology were evaluated under green house conditions and a few were screened under field conditions by physiological, biochemical and visual means.

This research forms the basis for evolving drought tolerant and disease resistant variants of tea.

Benefit to the industry:
By using biotechnology it has also been possible to develop synthetic seeds as well as plants that are expected to be drought tolerant. Since quantum loss of productivity due to drought is high, it is expected field use of these plants will help in cutting this loss. 

3. Extraction identification quantification and utilization of endogenous growth hormones in tea.

Salient findings:  The growing tip and the first internodes of a growing two and a bud shoots are the sites of GA3 and IAA synthesis in tea.

  • A balance of growth promoting hormone GA3 and growth retarding hormone ABA controls the growth and dormancy of tea plants. Topical application of GA3 temporarily reduced the level of endogenous ABA during winter and induced shoot growth for a short while.
  • Foliar application of GA3, IAA, Kinetin reduced chlorophyll content but has no effect on photosynthesis.

Benefit to the industry:
Seasonal and clone to clone variation in the distribution of endogenous hormones could provide a basis for determining economics of applying plant hormones exogenously.

4. Modulation of winter dormancy in tea.

Salient findings:

  • Out of 12 IHBT clones only one clone was identified as having the attribute of relatively low winter dormancy. For cloning of superoxide dismutase (SOD) gene from tea, a distinct isozyme of SOD was identified which was expressed only in the selected clone of tea.
  • The procedure to isolate good quality of RNA from tea was standardized and cDNA synthesis was achieved.

Benefit to the industry:
The biochemical basis of dormancy shows that it may be restrictive in its distribution in tea population. The gene responsible for this phenomenon and its analogue has been identified and can be utilized in future genetical research.

5. Selection, collection and preservation of tea germplasm from North Bengal area for development of improved planting materials for Dooars, Terai and Darjeeling

Objectives :

  • Survey of the old tea areas for identification of the diverse tea bushes having desirable agronomical traits.
  • Collection and preservation of selected plants from the Dooars, Terai & Darjeeling for development of cultivars for commercial plantation and generative clones for hybrid production through breeding, with cooperation of DTRC.
  • Establishment of tea gene bank at Nagrakata to promote tea breeding programs for development of hybrids for North Bengal tea plantations, including Darjeeling.

6. Generation and analysis of expressed sequence tags (ESTs) from the tender shoots cDNA library during blister blight disease infection and “banji” shoot formation in tea plant.

Generation and analysis of expressed sequence tagsHost Institute: UPASI Tea Research Foundation,
Valparai, Tamil Nadu.


  • Investigation on various sensors and sensor arrays useful for detection of taste, smell and visual appearance of black tea by electronic means by interfering with professional tea tasters.
  • Exploratory research towards development of a prototype for Integrated Quality Measurement System consisting of E-Nose, E-tongue and E-vision, with respect to teas aroma both North and South.
  • For quality evaluation, the teas from North and South will be studied, on a comparative scale.

B. Soils, Plant Nutrition & Water Management

1. Soil test crop response study for yield prediction and rationalization of nitrogen and potassium manuring in tea.

Salient findings:
Plant-soil interactions were studied using different soil test methods for nitrogen and potassium. The flush shoot and maintenance foliage were also analyzed for nitrogen and potassium. Field experiments were conducted by application of N:K2O fertilizers in four splits. The plot wise yield data were recorded for each split fertilizer application.

Benefit to the industry:
The basis of external application of nutrients, particularly the ways for nutrient optimization by tea, has been worked out to develop a deterministic model. It is expected this model will be the basis for developing a rational policy on tea manuring.

2. Ground water status of the tea soils of Assam and its impact on leaching loss of macronutrients and fertilizer management through remote sensing technique and other methods (Phase-I)

Salient findings:

  • The remote sensing data suggest that the depth of water table depends on the quantum of total annual rainfall on the outlet as well as the elevation of tea estates and soil profile characteristics.
  • These data will also help target the gardens with potential water logging.
  • Heavy rainfall causes more leaching losses of NPK. Therefore dressing of organic matter, besides replantation of shade trees to conserve soil moisture could lead to increase nutrient holding capacity of the soil.
  • Leaching studies carried out with Lysimeter and column indicated that three splits of YTD mixture were effective in increasing nutrient absorption by young tea plants in the year of plantation.

Benefit to the industry:
Development of effective technology for the management of fertilizers in tea soils of Assam in relation to ground water level has been made possible by remote sensing. This is the first study in the macro aspect of water management in tea soils, and how best to economize and optimize fertilizer applications in the situation.

3. Studies on Ground Water Status of tea soils of Assam and its impact on leaching loss of macronutrients and fertilizer management through remote sensing technique and other standard methods (II phase)

Salient Findings:

  • Remote sensing indicated wide fluctuations in water table depth in a particular season.
  • Soil should preferably be dressed with organic matter so as to reduce loss of nutrients and enhance availability of applied nutrients to maintain the high crop production.
  • In tea estate with water level far below the soil surface throughout the year, frequent irrigation is advised to boost up the crop production.
  • Leaching studies indicated 4 splits of YTD mixture application is more effective in increasing nutrient absorption by young tea plants.
  • In predicting leaching losses of NPK “Power Function Equation” was effective and precise.

Benefit to the industry:
Relevant findings on rainfall distribution, quantum, type of soil, topography etc., will guide tea estates in Assam Valley and North Bank to take decisions on irrigation, manure application and related aspects, for exploiting the production potential of the Tea Estate.

4) Studies on VAM Symbiosis and Rhizosphere Microflora and Effect of their Interactions on Growth and Nutrition of Tea Plant

Salient findings:
The study involves elucidation of the functional efficacy of tea rhizosphere in terms of the identification of the taxa and their interactions at different tropic levels. Based on a survey of representative tea estates in north east India, mycorrhizal colonizations of tea roots in areas differing in soil characteristics were quantified associated microbes were also identified possible reasons for their abundance or rarity were sorted out. A major finding is sourcing of weed species as alternative habitats of VAM inoculum.

Benefits to the Industry :
The beneficial microbes could be utilized for better nutrient management of tea and in the optimization of inputs. This could eventually help in economizing nutrients applied to tea.

5) Studies on mineralization of nitrogen, urea hydrolysis and nutrient releasing capacity of tea soils of South India

Salient findings:
South Indian tea soils have some specific characteristics that determine the absorption and utilization of applied nutrients by tea plants. The nutrient elements studied are Nitrogen, phosphate, potassium, calcium and magnesium, whose absorption, releasable amounts and the amounts stored within the soil were budgeted.

An interesting aspect of this study is the variation in the binding status of these elements in different sectors of tea soils in the South, which may be associated with the innate physical nature of the soil as it characteristics of  a particular area.

Benefits to the Industry :
The steps in the mineralization of each nutrient up to the point they are converted into available suggest these pathways are nutrient specific, and, to be an extent influenced by the availability from their natural pool within the soil.

  1. It is now possible to review application rates of both macro and micronutrients on a realistic basis.
  2. The releasable, cumulative and serial releases of nutrients have worked out.

6) Studies on Nutrient Release Pattern of Vermicompost and Vermiwash and its effect on uptake and Quality Assessment of Organic Tea

Salient findings:
With the current trend towards growing tea organically, the use of vermicompost and vermiwash this has gone up. This study pinpoints the elemental changes in course of absorption of vermicompost and vermiwash by tea roots and their effects in improving the physico-chemical properties of tea soils. In particular, the organic carbon level increased with the concomitant effect of enhancing mineralizable nitrogen level.

Both vermiwash and vermicompost at differential dosages increased the sulphur level in tea leaves, potash level considerably but phosphate level marginally.

Benefits to the Industry:
For organic culture the problems of sourcing nutrients will be greatly solved by these findings particularly for low energy organic input. Therefore, the culture of organic tea growing stands to gain both in terms of saving on chemical fertilizers and possibilities of quality improvement.

7. Studies on Mineralization of Nitrogen, Urea Hydrolysis and Nutrient (K,P,S,Ca, Mg and Zn) releasing capacity of tea soils of South India - (Phase - II)

Salient findings: A multidimensional study involving critical analysis of the pathways of nutrient release in the tea soils of South India. A model of macro and micro nutrients and their dynamics within the soil system, the physico-chemical conditions conducive to their utilization by tea plants through the interface of the root and soils, have been developed. The model proposed would also enunciate the ion movements though the soils of varying pH and moisture level pertaining to the nutrients, and their apportioning. The study covered different tea traits of South India and was therefore quite comprehensive.

Benefits to the industry:
The investigation would help developing a more rational fertilizer recommendation by taking cognizance of the nutrient balance sheet with the soil.

8. Studies on vermiculture and vermicomposting in tea growing areas

Salient Features:
Studies on the effect of vermicompost and vermiwash on the growth and development of tea plants showed a significant height stem thickness, root length, number of leaves and branches. Significant increase in fresh and dry weight of shoots and roots. The nutrient status of the soil containing the treated plants improved.

Benefit to the Industry:
Vermiwash and vermicompost fastened the growth of plants thereby reducing their duration in the cultivation practices.

9. Process Development and Enrichment of Vermicompost and its Assessment in Tea Rhizosphere grown at two different altitudes

Host Institute: Indian Institute of Technology, Kharagpur, West Bengal.


  • Soil enrichment, growth and yield of tea to be studied under experimental conditions. 
  • Process development of vermicompost in relation to characterization of raw materials, standardization of environmental parameters, selection of exotic earthworms and microbes, separation of drying technology.
  • Formulation and enrichment of vermicompost with N & P fixing and P Solubilizing microbes and its nutrient status.
  • Testing of developed biofertilizer for nutrient release pattern, and nutrient uptake by tea grown at different altitudes i.e. plains and hills.
  • To study the residual impact of vermicompost on physio-chemical and biological properties of soil at three different locations, plains, and high and mid elevation at Darjeeling.

10. Biochemical and Molecular approached to Drought Stress Tolerance in Tea

Host Institute: Department of Life Science, Assam University, Silchar.

Duration: 2007 – 2010


  1. Determination of biochemical alterations and related physiological aspects in different clones of Camellia sinensis under drought stress.
  2. Isolation of possible drought inducible proteins through electrophoresis and western blotting in tea.
  3. dentification of drought tolerant enzyme markers.

C. Plant Protection and Pesticide Management

1. Forecasting blister blight and biology and control of primary root diseases.

Salient Findings

  • The outbreak of Blister blight in South Indian tea fields is negatively related to sunshine hours but positively with humidity. This finding could be extrapolated to predict the probable pandemic outbreak of this disease that causes enormous loss in crop.
  • Out of four common primary root diseases, only Red root disease is of consequence. The rest occur only on a minor scale. For biological control of tea root disease application of Trichoderma species proved effective.

Benefit to the industry:
Development of a model to forecast the appearance of blister bight. Strategies for controlling blister and seven adjunct root diseases of tea have also been formulated to provide the most economic and lasting control of tea diseases. This CD Rom on blister control is under commercial use.

2. Adaptive research in biological control of scale insects and mites infesting tea

Salient Findings
Major natural enemies of the pests from different areas of North East India have been ranked in the order of their functional efficacies. The periods of abundance of the natural predators have been noted with suggested ways and means to optimize the utilization of predators. Mass cultures of predators and techniques for their release have also been worked out.

Benefit to the industry:
This study indicates the possibilities and benefits of non use of pesticides for economic control of major tea pests. The full range of activities, including mass rearing and controlled releases of pest natural enemies have been developed.

3. Bio-control of tea pests using indigenous natural enemies

Salient Findings
Major agencies for natural control within the tea ecosystem of Assam have been identified.

Benefit to the industry :

Natural control of some major tea pests in Assam by the utilization of their specific natural enemies is the exploratory aspect of this study. Having identified the predators, ways and means were developed for mass rearing of these predators, for their eventual release in tea fields. 

4. A search for the arthropod enemies of tea pests from Darjeeling slopes and adjoining plains with a study on their efficacy (Phase-I).

Salient findings:

  • Natural enemies associated with tea pests were high in organic as well as conventional tea plantation.Argyrophylax has potential for biocontrol of red slug caterpillar population.Cotesia sp. is also an effective biocontrol agent against red slug, looper caterpillars in Terai, the Dooars and slopes of hill regions.
  • Reduviids and Pentatomids were also evaluated as powerful associated bio-agents.This Study revealed coccinellid predators are quite active against tea aphids, jassids and thrips populations.
  • Life table analysis of red slug and tachinid relation showed proportional mortality is more at pupal stage than at the larval stages.

Benefit to the industry:
This broad based study provides a key to the level of abundance or otherwise of the natural enemies of some major pests of tea in the Dooars and Terai belt. The seasonal abundance of these natural enemies can be synchronized with good agricultural practices to provide ecologically sound pest control means.

5. Integrated control of Helopeltis theivora Waterhouse

Salient findings:
Bio-ecology of Helopeltis theivora was studied for possibilities of having different bio-type, rate of fecundity, oviposition response, development (growth index), feeding behaviour, intensity of infestation, probing behaviour and growth of population. These are important for integrated management techniques to control this pest effectively.

Benefit to the industry
This study shows how the weak links in the life system of Helopeltis can be utilized in developing strategies of economic and long term control of this pest. Several predators and pathogens that feed restrictively on this pest have been identified.

6 - 8. Pesticide Residue in Tea.

Host institutes: Tea Research Association, Tocklai Experimental Station, Assam
UPASI Tea Research Foundation, Valparai, Tamil Nadu
Institute of Himalayan Bio-resource Technology, (CSIR) Palampur, H.P.

Salient findings

6. Tea Research Association
Established a modern pesticide residue laboratory at Tocklai, Jorhat, with NTRF fund an air conditioned instrumentation room equipped with GLC with ECD (electron capture detector) and TSDC (Thermoinic specific detector), HPLC, and other necessary equipment. Pesticide residue levels of seven-pesticides; ethion, dicofol, quinalphos, monocrotophos, phosphamidon, chlorpyriphos and endosulfan were sampled and analysed serially after standardizing the procedure.

7. UPASI-Tea Research Foundation
Established a new residue analytical laboratory with two air-conditioned instrumentation rooms at Valparai. Also Standardized valid methods for extraction, clean up and standardized instruments for the analysis of ethion, dicofol, endosulfan, quinalphos, chlorpyrifos, deltamethrin and acephate residues from black tea samples. Methodologies developed were validated by fortification studies.

8. Institute of Himalayan Bio-resource Institute, Palampur
Established a new residue analytical laboratory. Standardised method of analysis of residue limits for seven pesticides applied in tea fields of Himachal Pradesh. Based on the results, measures to keep the residues, below the MRL have been worked out and accordingly advised to member tea estates of Himachal Pradesh.

Estimation of pesticide residues present in tea brew indicated a drastic reduction compared to those of dry made tea.

Benefit to the industry :
The coordinated project on residual pesticides helped developing strategies for minimizing the levels of pesticides of different genesis in tea. Basically good agricultural practices completed with need based applications of pesticides have helped in reducing the levels of metabolites of pesticide. These studies also underpinned the need for developing interactive monitoring process to detect the levels of pesticidal metabolites in tea brew. Based on such residue data, a national protocol was developed for fixing MRLs in tea.

9. Ecological Studies into the association of Pratylenchus loosi and other nematodes with tea in higher and lower altitudes of Darjeeling hills

Salient Findings and Benefit to the industry
Research carried out in representative tea estates of Darjeeling revealed that during winter, nematode in tea estates at higher altitudes shows lowest population, indicating its seasonal vertical migration towards lower warmer region. Populations were higher in lower altitudes confirming the downward vertical migration during winter. During summer the migration pattern is opposite. It is also revealed that no management practices are following against plant parasite nematodes.

10. Studies on the Borers (Cerambycidac: Coleoptera) attacking shade trees of tea plantations

Salient findings:
49 pest species were identified in the tea fields of 19 Tea Estates in the Dooars and Darjeeling. Out of these there were 10 defoliators, 4 bark eaters, 18 sap suckers and 17 hard wood borers. Graded increase in temperature / relative humidity during February to July helps in pest population increase. About 40% of the shade trees were found to be affected.

Benefits to the Industry :
A calendar of shade trees and pest has been prepared for the benefit of industry. This would helping identifying the appearance of the pests on shade trees.

11. Evaluation of bio-control potential of some arthropod natural enemies of major tea pests from Darjeeling slopes and its adjoining plains - 2nd Phase

Salient findings:
Application of pesticides on major tea complexes in the tea plantations of sub-Himalayan zone creates special problems in terms of building up pesticide residues and deterioration in the quality of tea. To overcome this twin problem this research was directed to find out the natural enemies of tea pests, the predators and parasites that would help in bringing the pest population levels below their damage thresholds.

Pest-specific predators, their feeding sequence and developmental pathways in relation to pest cycle have been worked out. Cross parasitization of major tea pest has been developed for the first time.

The feeding rate of major predators, their developmental rate and means for synchronizing their activities with those of pests have been worked out.

Benefits to the Industry :
Augmentation of natural enemies of pests would effect a reduction in the quantum of pesticides now being used. Spin off effects would include improving tea quality and production of residue free tea.

A hand book (e-book) giving details on utilization of natural enemies is being published by NTRF.

12. Studies on the volatile profile of cut stems of Montanova bipinnatifida an attractant for trapping shot holes borer infesting tea

Salient findings:
This is the first study of its nature involving as it does tapping the shot hole borer beetles (a deadly pest in South Indian tea plantations) by alluring them with volatile chemicals emanating from the dried stems of the weed Montanova bipinnatifida. This is of considerable biological significance because the borer beetle, pandemic to tea, seems to be attracted by volatiles from a non-host plant as well. Since a series of volatile compounds are involved, they have been sorted out in order of their attractiveness.

Benefits to the Industry :

  1. Beetles are being trapped in traps based on the characteristic volatiles, located at convenient locations in the beetle infested fields. A sizeable population thus trapped can be effectively done with, without use of any pesticide.
  2. Trapping of shot hole borer constitutes a major component for integrated management of shot hole borers as it is both ecologically and technologically feasible proposition.

13 - 15. Microbial Control of Tea Pests - 1st Phase, 2nd Phase & 3rd Phases.

Salient findings:
Using well planned sampling procedures, a series of microbial species, several species of fungi and Bacillus thuringiensis were isolated from different taxa of tea pests. Though these isolated microorganisms were basically from pest species, in field populations they did not cross the damage thresholds. This study has established that by biological augmentation of microbial species it is possible to develop non-pesticidal means for management of major pests including shot hole borers by Beuvaria, Red spider mites by Paecilomyces and Bacillus thuriagenise and thrips by Aspergillus.

Benefits to the Industry:
Several technical formulation using the pathogens as functional units have been developed. These formulations as wet-table powders have been successful in the management of specified pests. Wettable powder formulations have been commercialized, and rates of their applications under field conditions have also been worked out.

16-18. Studies on pesticide Residues in Tea : Second Phase.

Salient findings : These three projects have identified the critical path ways of the degeneration of pesticides molecules of different configurations and determined the minimal levels of pesticides in black tea. Using a deductive process this study has been made possible to determine both the time and rate constants of pesticide degradations and dissipation during different phases of tea processing, right from plucking to packing.

Concurrently, following international code residue levels of pesticides of diverse functional quotients have been determined, and GAP and GMP worked out.

Benefit to the industry : These studies have established the image of Indian tea is a chemical free clear product.

19. Studies on the volatile profile of cut stems of Montanova bipinnatifida an attractant for trapping shot holes borer intesting tea - Phase II.

Host Institute : UPASI Tea Research Foundation, Valparai, Tamil Nadu.

Duration : 2005-2007

Salient Features : In a very unique approach towards pest management, this study basically involved isolation and identification of volatile compounds from the dried stems of Montanoa bipinnatifida for their potencies in the management of shot hole borers with a major pest of tea in South Indian tea plantations. Screening of components was done by electro-antennogram and wind tunnel bioassays.

The compounds isolated included α-pinene, trans-caryophyllene, germacrene-D and β phellandrene. They all had varying effects in trapping the shot hole porers.

Based on the attracting attributes of the compounds isolated, field traps were developed utilizing their attracting potentials. They have been field tested and commercialized.

Benefit to the industry : Simple and economic means of non-pesticidal control of shot hole borer has been made possible by this study.

20. Investigation on the bio-resources for the development of Integrated Disease Management (IDM) strategy against root-knot nematode and certain soil brone fungal pathogens associated with nursery tea.

Salient Features : A study oriented towards utilization of natural fungal antagonists for effective control of eelworms and soil borne fungi that infect roots of young tea in nurseries. The objective was to develop biological means that would eliminate or reduce the dependence on fungicidal chemicals and nematicides for the control of the pathogens and eelworms respectively. Several taxa of high potency antagonistic fungi in effecting pathogene control have been identified, cultured and utilized with highly promising outcome.

Benefit to the industry : This is a major step towards developing sustainable chemical free tea with possibilities of biological control of tea pathogens.

21. Susceptibility change in Tea Mosquito Bug, Helopeltis theivora, in North East India.

Salient Features: The project was essentially addressed to the possible development of resistant strains of Helopeltis theivora, a major pest of tea in north east India. The pest is quite rampant and survives intensive insecticidal applications. The apprehension therefore was whether or not there had been mutants strains with variable susceptibility to insecticides. Morphometric analysis showed this could be a distinct possibility.

Benefit to the industry: The research would help tea sector is formulating a rational and rotational pest management programme, which would be economic and eco friendly.

22.  Utilization and Implementation of Native Microbial Bio-agents for Control of  Termite Pests in Tea Plantation of North East India

Salient feature :
Developed an effective package for integrated management of termite pests incorporating    the entomopathogens along with other IPM tools around North East India.

23. Studies on Pesticide Residues in tea for setting MRLs – Phase-III

Host Institute: UPASI Tea Research Foundation, Valparai, Coimbatore, Tamil Nadu


  • Generate a database for establishing maximum residue limits (MRLs).
  • Investigate the metabolism and dissipation of selected pesticides.
  • Detect the level of residue in black tea and tea brew of the selected pesticides that include glyphosate, fenvalerate, beta cyfluthrin, propargite and imidacloprid.
  • Compare gene expression profiles at different time intervals in mouse skin from experimental animals demonstrating anti-promoting activity;
  • For confirmation of any observations in vivo, effects of PBPs will be studied in metabolically competent cells lines.

24. Development of mass rearing technique for two major predators of red spider mites

Host Institute: UPASI Tea Research Foundation, Valparai, Coimbatore, Tamil Nadu


  1. Development of mass multiplication techniques for Stethorus gilvifrons and Oligota pygmaea, the two important predators of red spider mites.
  2. Multi-location field trials on the evaluation of predatory potential of the two predators using recapture and release technique and their establishment under different agro-climatic conditions, and field release under normal estate practice and in organic tea gardens.
  3. Evaluation of the commonly used (recommended) acaricides / insecticides on the predators.
  4. Evaluation of the role of kairomones (plant derived volatiles) on the behaviour of predators.
  5. Training and awareness holera on familiarizing the mass rearing technique of important natural enemies for incorporation in the biological control strategies for efficient management of tea pests.

25. Developing soil suitability criteria for replanting based on soil health parameters.

Host Institute : Tocklai Experimental Station, Tea Research Association, Jorhat, Assam.

Objectives :

  • To prepare a data base for physical (including water holding capacity of the soil, and exchangeable aluminium), chemical and biological parameters in different soil types under three different conditions viz. old tea soil due for uprooting, replanted after proper rehabilitation and directly replanted without rehabilitation.
  • To establish the duration of rehabilitation, degree and role of rehabilitation and its nature in different types of soil in improving soil properties and productivity.
  • To determine the minimum number of soil parameters and their ranges for deciding need for rehabilitation for different duration.

26. Developing a low input weed control programme to reduce chemical load in tea soils

Host Institute : Tocklai Experimental Station, Tea Research Association, Jorhat, Assam.

Objectives :

  • To determine the level of control possible with non traditional herbicides against various species of weeds in tea areas, and their residues on tea.
  • Effect of mixtures of traditional and non traditional herbicides for effective weed control, with reduced load of individual chemicals.
  • To find out the allelopathic effect of weeds.
  • To work out the economics of non traditional weed control.
  • Evaluate CIB registered chemicals or those in the pipeline, and determine their comparative efficacies.

27. Investigation on the bio resources for the development of Integrated Disease management (IDM) strategy against root-knot nematode and certain soil borne fungal pathogens associated with nursery tea – Phase II

Host Institute : Assam Agricultural University, Jorhat, Assam,

Objectives :

    1. To study on interrelationship between root-knot nematodes and certain soil borne fungi and the impact of latter in reducing the disease severity in nursery tea.
    2. To evaluate the efficacy and standardize the economic dose of some organic amendments and promising fungal antagonists against root-knot nematodes affecting tea nurseries.
    3. To evaluate soil heating and soil solarisation for nematode control. 
    4. Evaluation of organic substrates as a media for effective mass multiplication of promising fungal antagonists and growth of the seedlings with methods of application.

28. Assessment of spiders as second order of bio-control agents in tea ecosystem with special reference to Assam and Dooars of West Bengal

Assessment of spiders as second order of bio-control agents

Host Institute : University of Calcutta,

Duration : 2008-2011

Objectives :

  • To classify the diversity of spiders in tea ecosystem in tea areas adjoining forest and non-forest areas.
  • Generation of data on the spider taxa of conventional and organic tea gardens adjacent and away from forest.
  • To generate data on food spectrum of spiders and inventories of spider species as bio-resource in the control of tea pests.
  • To prepare a database of the spider taxa in tea ecosystem and recommend bio-resources of the study area.





D. Quality Improvement

1. Role of enzymes in tea processing

Salient findings
This investigation provides basis for improvement of quality of black tea in terms of enhanced activities of some compounds of positive consequences in quality. It also attempts inducing polyphenol oxidase from mushroom during tea processing to improve colour and strength of the infusion.

Benefit to the industry
The results indicate possibilities of improving quality of tea. A bulletin was published by NTRF based on the results of this project.

2. Studies on aroma complex of tea from kangra region

Salient Findings:
The aroma of first flush tea produced in kangra region is comparable to that of Darjeeling tea, on the basis of chemical profile. Procedures for extraction and purification of enzymes responsible for aroma generation in tea were standardized. Conditions were also standardized for acid hydrolysis of tea shoots and estimation of aroma generation thereof by Gas chromatograph (GC).

Clonal variations were noted in the activity of the enzymes that are responsible for generating floral aroma in various clones in kangra valley.

Benefit to the industry
It has now been possible to identify the specific compounds that provide characteristic aroma to Kangra tea. By chemical manipulation at the level of processing, it might even be possible to create Darjeeling flavour in Kangra.

3. Studies on Pacha Taint in CTC Tea.

Salient findings
Chemical compound trams-2-hexenal is responsible for “Pacha” taint and lipid content for Pacha Odour. Its limit has been identified for taking suitable measures. Duration of primary cycle needs to be reduced to resolve the problem. Pacha prevention by giving suitable treatments produce good quality tea.

Benefit to the industry
Recommendations for producing tea of good quality by removing “Pacha” odour have been worked out which have highly benefited the tea of South India where this problem of “Pacha” odour of made tea is common.

4. Extraction, Identification and Quantification of volatile flavoury constituents (VFC) in TRA released Darjeeling clones and standardization of process variables in Darjeeling tea with special reference to V.F.C.

Salient findings
Flavour profile of 30 clones of Darjeeling have been documented for the first time. Linalol oxides and Geranial are more characteristics of Darjeeling flavour. Formation of flavour is maximum during the rolling stage followed by drying.

Benefit to the industry
Flavour index for 30 clones have great potentiality for new plantation/replanting in Darjeeling. Suitable modification at manufacturing stage may help industry to enhance the flavour and quality using the flavour index.

5. Studies on Attributes of Polyphenols from Kangra Tea [Camellia sinensis (L) O Kuntze]

Host Institute: Himachal Pradesh Krishi Vishvavidyalaya (CSKHPKV), Palampur


  • To determine the phenolic profiles and their seasonal changes in fresh green tea shoots, and to assess the impact of chemical variation on tea productivity.
  • Identification of local tea cultivars having different levels of polyphenols for possible use of some of them in plant breeding.

6. Impregnation of Oxygen During Fermentation of CTC Tea.

Host Institute : Tocklai Experimental Station, Tea Research Association, Jorhat, Assam

Objectives :

  1. Optimizing the oxygenation process from an outside source during fermentation process and evaluating its effects in improving the quality of tea.
  2. To standardize the parameters including biochemical ones, involved in the envisaged process, with particular reference to continuous fermenting machines.

Results: There is diverse opinion on the subject. While report from South India is in favour of addition of oxygen for oxidizing tea for higher quality, but NE does not favour it much since the results are not that encouraging.

7. Nutrient Management Strategic Productivity and Quality of Tea plantation in selected Tea Gardens in North Bengal.

To characterize the status of plant available soil pools of phosphorus (P) potassium (K) and sulphur (S) in four differentially graded tea gardens located in Terai and the Dooars areas of North Bengal in relation to organic matter dynamic.
To monitor the changes of the available pools of P, K and S at selected intervals, for ascertaining the depletion/build-up of these nutrients in the soils under examination.
To examine the critical leaves of P, K and S in tea leaf for ensuring acceptable yield.
To study the changes of pools of different fractions and / or forms of P, K and S from different depths of soils at selected intervals round the year in order to examine the fate of soil pools of P, K and S in the experimental sites, and relate them to organic matter status.
C:N ratios at different areas to be worked out for correlating them with the above noted objectives

Salient Features:

The critical concentration of P in tea leaf was found to be 0.31%, when 90% relative yield as the average equivalent to maximum yield can be obtained.

E. Green Tea Processing

1. Standardization of green tea manufacture - Phase-I.

Salient findings
Green tea manufacture was standardized with respect to inactivation of polyphenol oxidase, rolling and drying for quality manufacture. Parched and sun dried green teas contained lowest levels of total phenols and catechins and their infusion was dull in colour with slight burnt odour.

Steam inactivated and oven/microwave oven dried green teas contained high level of total phenols and catechins and their infusions were bright with umami taste. Microwave inactivated and microwave dried green teas show highest levels of total phenols and catechins and individual catechins, and their infusions were bright in colour and sweet in taste with subtle pleasant odour.

Benefit to the industry
A major outcome is the steam inactivation of green teas by microwave treatment. Unlike conventional system, this new approach has resulted in high level of catechins, and hence, overall quality improvement as reflected in bright colour and pleasant aroma is Kangra teas of most varieties.

2. Standardization of Green Tea Manufacture (Phase II)

Salient Features : For the first time attempts have been made to standardize all the phases of manufacturing green tea produced in Kangra valley of North-West India, from a biochemical perspective. Most important is the enzyme inactivation which could be achieved by overcoming limitations of microwave technology, and a physio-chemical regime conducive to this chemical process has been established. This apart, the intricacies of rolling and drying have been so modulated as to give the quality at its best from the well known China hybrid clones of Kangra Valley.

Benefit to the industry: Improvement and sustainability of quality will certainly place Kangra tea in a better position among the connoisseur by tea.

3. Standardization and optimization of processing conditions in relation to biochemical parameters for manufacture of green tea and oolong tea


  • Standardization of green tea processing conditions to achieve International quality from cultivars available in N.E.India.
  • Assessment of scope of production of Oolong tea from cultivars in N.E.India.
  • Electronic monitoring and control of process variables in production of Green Tea and Oolong tea.

F. Organic Tea: Processing / Improvement

1. Promoting Organic Farming for Tea Productivity and Quality under Hill and Mountain Agro-system

Salient findings:
The treatment of organics against the insect pest of tea resulted in significant reduction of pest population over the control.

G. Ergonomics

1. Ergonomic assessment of working postures assumed by workers engaged in tea cultivation.

Salient findings:
Working posture of male and female workers proved that musculo skeletal problem were in some cases responsible for acute back pain, pain in legs and arms. The bad working postures were responsible for low productivity of workers. Activities should be carried out with breaks to give relief to the workers form undesirable physiological fatigue. An ergonomically designed basket for plucking is found to reduce fatigue and help increasing plucker productivity.

Benefits to the Industry
The findings are useful for a broad understanding of the occupational health of the workers. This will provide guidance in identifying steps that could be taken to improve the working conditions as well as health of the workers and help in enhancing workers productivity.

2. An ergonomics - oriented physiological study on workers and workplace environment of tea manufacturing units of Eastern India and its relation with performance and productivity

Salient findings:
The principal finding of this study carried out in different sections of a processing unit in a moderate sized and well managed tea garden is that workers exposed to a noise level between 86 to 123 dB, for 5 - 10 years, had significant liver functions alterations. Further, high noise level could be responsible for production of increased free radical and subsequent alteration in hepatic function enzymes and these could affect performance and productivity.

Benefits to the Industry
Optimization of the noise level in various sections of tea manufacturing unit to control noise pollution would improve performance and productivity of the workers.

3. Occupational Mobility of Plantation Sector Labours in Assam : Determinants and implications.

Salient Features: A demographic study, made for the first time, on the dynamics of labour movements within tea gardens in the context of social changes, particularly with the opening up of job opportunities outside the tea sector. The study has underpinned the qualitative differences in the attitude of tea garden labourers between and within generations towards traditional jobs in tea estates and opportunities outsider. The impact of socio-economic changes on the work perception of tea estate workers has been underscored and quantified.

Benefit to the industry : Tea sector planners and labour welfare organization would get valuable database in planning and formulating labour oriented policies.

4. A Productive improvement - linked study on women tea pluckers of Eastern India with special considerations to their working comfort, welfare and health status.

Salient Features : An ergonomic study oriented towards developing a practical frame work for improving productivity of workers from the perspective of functional physiology. Taking biological and physical variables involved during such field operations as plucking, the need for a strong correlations between body physiognomy and bush geometry has been established.

Benefit to the industry : This would eventually provide a database on the reasons for varying performances of workers, and reasons thereof. From this point, effective labour management strategies could be thought of.

5. Ergonomic Assessment of technologies used by the workers in performance of different activities in tea cultivation.

Salient Features : This study was oriented more towards working out the energy cost of performing field work of different nature. It was shown that the energy cost for a worker would vary according to the nature and dimension of work, with energy level of the worker being central to his / her functional ability. The study suggests even by marginally improving the tools or carrying baskets, the energy cost could be considerably reduced, increasing thereby the efficiency of work.

Benefit : Valuable to tea sector for developing strategies for labour welfare and improving efficiency of workers - tea being totally labour oriented.

H. Product Diversification

1 & 2. Development of a Manufacturing Process for Green Tea Polyphonels from Fresh Leaves of Assam Tea - Phase - I & II

Salient findings:
This project is oriented towards industrial use of tea polyphenols and is initiated to identify the steps leading to extraction of polyphenols from green leaves of tea. Five functional routes have been identified each with its specific causal mechanisms.

In three of the identified steps, a substantial amount of polyphenols was lost as extraction processes continued, and were therefore considered uneconomic. Liquid to liquid operation was the source of maximal loss of polyphenols.

The two final steps or routes involve integration of both the processes of decaffeination and solid-liquid, as opposed to liquid - liquid, system. This system yielding about 80 per cent of total polyphenols, but decaffeination was not totally optimum because only the free fractions of the caffeine could be removed. Even the use of supercritical carbon dioxide did not significantly improve the situation. The study also pointed that though a temperature near 100°C is highly conducive to the extraction of all components of catechins, it also leads to oxidation, epimerization and polymerization of the final product. Extraction at 80°C with a step time of 30 - 40 minutes was optimum.

Benefit to the Industry
The solid - liquid extraction model is most viable option from a technological perspective and can be exploited commercially.

I. Machineries

1. Exploratory studies on development of electroKolkatanic nose for tea – C-DAC

Salient findings
Though the basis of tea quality continues to be an enigma, in general, it is agreed that a wide array of volatile and non-volatile compounds interact in developing the profile of aroma in tea, despite its geographic and varietals variations. Though the components of quality can be identified bio-chemically, most processes involved are sub-optimal and no means exist to monitor the processes parameters on line.

The attempt to develop an electronic nose is a step in this direction though it might not decode all or every step in the complex process with its manifestations in terms of its contributions to build up of tea aroma or quality in a broader sense.

The electronic nose essentially computerizes miniature arrays of rather unspecified sensors that generate characteristic signal patterns when exposed to gaseous on emissions from leaves. 

Benefits to the Industry

  1. The e-nose, when further refined can provide a concept for monitoring the characteristic and reproducible signal patterns specific to aroma of particular brands.
  2. It can identify different configurations of compounds involved in quality development.

2. Quality measurement of Black Tea by Electronic means – Integration of E-Nose, E-Tongue and E-Viosin 

Host Institute: Centre for Development of Advance Computing, C-DAC, Kolkata.


  1. Investigation on various sensors and sensor arrays useful for detection of taste, smell and visual appearance of black tea by electronic means by interfering with professional tea tasters.
  2. Exploratory research towards development of a prototype for Integrated Quality Measurement System consisting of E-Nose, E-tongue and E-vision, with respect to teas aroma both North and South.
  3. For quality evaluation, the teas from North and South will be studied, on a comparative scale.

3. Development of a single cut machine for converting green tea leaves into granulated black tea (CTC type

Host Institute: Agricultural & Food Engineering Department, Indian Institute of   Technology, Kharagpur


  1. To re-engineer design of cutting unit of the micronizer for higher efficiency,
  2. To minimize the power consumption of the micronizer.
  3. To study the physical appearance of the cut leaves, bio-chemical changes under fermentation, drying and quality assessment of made tea produced from the machine.
  4. To develop a prototype micronizer and to assess its economic feasibility, with particular reference to high capital to output, and output to power ratios.

4. Modification of SEPTU Micronizer for converting Green Tea Leaves into Granulated black tea.

Objectives : To re-engineer the design of the cutting unit of the Micronizer for higher efficiency for power consumption, improvement in physical appearance, and finally development of  economic model like a prototype modifying the micronizer.

Benefit to the industry:

The improvement is done on the model and after satisfactory trial run, pilot studies are going on towards commercialization.

J. Pricing of Tea

1. Quantitative Study of Tea Industry – Market, Pricing and Organization

Objectives :

  1. To work out the degree of competitiveness of Indian tea in world market and factor influencing on it.
  2. Forecast market trends for the near future with help of econometric tools.
  3. Explanation for institutional problems of plantation and marketing, and pointing out the reasons for the duality of tea plantations and poor percolation of benefit from final market to small tea growers.
  4. Analysis of the tea auction market and pricing holera.
  5. Pros and cons of 100% FDI to motivate growers and joint venture for the development of tea industry.
  6. To suggest the policies for retail chain collaboration for the benefit of tea growers and avenues of strategic export promotion to expand market for Indian Tea.

Salient Findings: The study yielded some basic findings from field surveys. This is essentially a discussion of different primary stakeholders in the tea industry like big growers, small growers and bought-leaf factories from the tea producing region of North Bengal.

K. Workers’ Nutrition and Health

1. Impact of Video-show developed for disseminating nutrition messages to female tea plantation workers of Assam

Host Institute : Assam Agricultural University, Jorhat, Assam,

Objectives :

2. Resource Utilization in Tea Industry: Current Problem and Future Prospects with special reference to labour

Objectives :

  • To suggest measures for converting the utilized land in the tea gardens into productive assets, in other words, to suggest a land use plan of utilized land in tea gardens.
  • To examine the Educational scenarios in tea gardens.
  • To find out the Basic Services and Amenities Provided to Tea garden workers.
  • To assess the feasibility and implications of Consumer Price Index (CPI) – linked variable DA, minimum wage calculation according to the prescribed norms of trating a family as three consumption units.
  • To explain the reasons for Labour immobility in tea gardens and to suggest ways to tackle this problem.

3. Health status of female tea garden workers with special reference to incidence of anemia and malnutrition

Host Institute: Vivekananda Institute of Medical Sciences, RKMSP, Kolkata.   


  • To study the health of female workers in tea gardens of Assam and other NE states with special reference to anaemia and malnutrition.
  • To provide preventive measures and treatment of anaemia and malnutrition.
  • To study results of treatment with reference to levels of Hb%, general health status, infections and fertility after a period of two years.

4. Social security benefits and socio economic conditions of small planters and plantation workers in Tamil Nadu and Kerala – A study

Host Institute: Department of Economics, S.T.Hindu College, Nagercoli


  1. To find out the socio-economic conditions of small growers of tea plantations in Tamil Nadu and Kerala.
  2. To compare social security of their workers in small sectors with those of large corporate sectors.

L. Human Health Benefits

Anticarcinogenic and antimutagenic

1. Anticarcinogenic and antimutagenic effects of black tea

Salient findings:
Cancer is one of the most dreaded diseases affecting millions of people worldwide. In this research, the antigenotoxic effects (both antimutagenic and anticarcinogenic) of black tea together with its mechanistic aspects were evaluated in experimental studies. The antigenotoxic activity of black tea was identified in microbial and mammalian in-vivo systems.

The anticarcinogenic activity of black tea was identified in long term in-vivo animal bioassay, lung and esophageal tumorigenesis. Both benign and malignant tumor development induced in mouse skin was reduced by black tea administration. The frequency of adenomas and squamous cell carcinomas induced by either by N-Nitroso-dietlyl-amine (DEN) or BaP were also suppressed by black tea in lung and esophageal tumors.

The molecular mechanisms of cancer chemoprevention for black tea were studied for its apoptosis (programmed cell death) inducing potential.

This study established that black tea and its ingredients, mainly polyphenolic fractions were effective in inhibiting genotoxicity and chemical carcinogenesis as well as modulating gene expression.

Benefit to the industry
These findings have provided a new contour to the health benefit attributes of tea. The information provided will broaden mass appeal of tea as a healthy beverage suited a to modern life style.

2. An approach to induce selective apoptosis in tumor cells without harming the normal cells of the host by black tea extract.

Salient findings:
The molecular mechanism of black tea extract-induced tumor apoptosis revealed that tea modulated the intracellular environment of cancer cells towards apoptosis by regulating the balance between pro and anti apoptotic factors that were otherwise in favour of cancer cell proliferation.

  • Black tea acts as immune function restorer and protects the immune system in the tumor bearing host.
  • These findings are important in formulating future cancer therapy because unlike other means black tea is non-toxic by itself and ameliorates cancer induced toxicity of the host. Therefore its emergence as a harmless cancer drug is very high.

Benefit to society
Undoubtedly the findings that the black tea ameliorates the host’s immunosuppression due to cancer will be a step forward towards designing therapeutic measures that will selectively kill tumor cells without harming the normal cells, e.g., immune cells of the host.

3. Antioxidant role of black tea infusion on the oxidative damage of proteins.

Salient findings:
Black tea (BT) prevents cigarette smoke (CS) induced oxidation of bovine serum albumin (BSA) and oxidative degradation of guinea pig lung, liver and heart microsomal proteins. The antioxidant effect of black tea was similar to that of green tea. Black tea prevents microsomal protein degradation by preventing oxidative modification of the proteins.

Benefit to the Industry
Having identified the principal compound that induces smoke related cancer, it is possible an antidote based on tea can be developed.

4. Use of black tea in reducing cytotoxic effects of heavy metal pollutants.

Salient findings:
Tea when given alone or with sugar and milk (administered for 7 days) is able to protect significantly against clastogenic activity of sodium arsenite. Protection against arsenic cytotoxicity by prolonged dietary administration of black tea is of importance in view of the widespread exposure of human populations to arsenic through drinking water from tube-wells.

Benefits to the Industry
Arsenic and other pollutants in water affect human health by modifying the cellular functions, as reflected by chromosomal aberrations and general cytotoxicity. This study establishes tea’s potential against arsenic toxicity at cellular level, especially by dietary administration of tea. 

5. Evaluation of the medicinal properties including antineoplastic property of tea root extract and its active constituents

Salient findings:
The anticancer activity of di-and tri-tufenes and other compounds present in tea is reported. For the first time the cytotoxic apoptozemic effect of tea root extract (TRE) and two of its steroidal saponinas named TS1 and TS2 have been evaluated in tumour cell lines and on cells from leukemic patients. It was found that TRE, TS1 and TS2 caused cytotoxicity and the TRE apoptosis in both cell lines.

Benefits to the Industry
In the long run industry may be benefited by using tea root extract as medicinal raw material.

6. Prospective anti-osteoporosis and anti-hepato-pancreatitis effects of black tea extract.

Salient findings:

Black tea extract may prevent ovariectomy induced bone loss by maintaining calcium homeostasis as well as by modulating NF-kB mediated cytotine production from cells of mononuclear lineage by altering third oxidative status. Also BTE prevents high-fat diet-induced oxidative stress, hepatic injury and inflammatory changes.

Benefits to the Industry
Recommendation of BTE as a natural protective agent against hypogonadal osteoporosis, ethanol induced hepatitis and high fat diet induced pancreatitis may help tea industry to promote this beverage as a natural health drink by emphasizing this particular attribute.

7. Modulation of Cytotoxicity and Genotoxicity of Arsenic Compounds in Mammalian cells by Tea extract and its Polyphenols

Salient findings:
Toxicity due to arsenic is a serious problem in different parts of West Bengal. This study reveals that tea extracts like pure tea polyphenols have promising chemopreventive activity as well as enhancing repair activity against environmental arsenic contamination. Black tea and TF are equally effective in combining arsenic toxicity, genotoxicity and clastogenicity.

Benefits to the Industry
Tea may help people from the adverse effects of arsenic contamination, and this aspect can be elaborated in projecting health benefits of tea.

8. Pharmacological Evaluation of the Medicinal Properties of Indian Black Tea

Salient findings:
In different in vitro model studies tea infusion showed significant antioxidant activity and scavenged hydroxyl, superoxide, Diphenyl picyl hydrazide (DPPH) free radicals and hydrogen peroxide. The infusion significantly reduced lipid peroxidation induced with carbon tetrachloride and NADPH.

In various animal models of inflammation, the infusion (following treatment) decreased oedema, PGE2 and in a manner seminar to the non-steroidal anti-inflammatory agents.

Benefits to the Industry
The additional benefit would broaden the medicinal properties of tea in the control and or cure some of our common diseases.

9. Therapeutic potential of black tea in various gastrointestinal (GI) disorders: Study with theaflavins and other black tea constituents

Salient findings:
Darjeeling tea has the attributes to inactivate the virulent strains of vibrio cholerae responsible for severe diarrhea. There is evident that oral consumption of tea compounds could effect amelioration to a great extent.

Benefits to the Industry
This aspect, i.e., the effectiveness of tea against a tropical disease would give on edge to the industry in presenting the unique therapeutic potential of tea.

10 & 11. Evaluation of the role of Black Tea in the Prevention of Lung Cancer - Phase-I & Phase-II.

Salient findings:
The results strongly suggest that black tea does have a role in prevention of lung cancerioma and two major active tea compounds are potential chemopreventive agents. Drinking tea can effectively restrict cellular proliferation and induce apoptosis at the target site. Since a proper balance between these two important physiological processes determine the post initiation progression towards malignancy, black tea and its native compounds are capable of preventing tumor development by modulating these two processes.

Benefits to the Industry
Results of this research proves the beneficial effect of tea drinking in the prevention of Lung Cancer. Industry in its promotional campaign can objectively use this outcome.

12. Investigations on chemopreventive efficacy of Black Tea, the popular beverage in India.

Salient findings:
In vivo and In vitro studies with isolated black tea polyphenols established their strong anti-promoting activity against initiation of cancer. Five fractions of polymeric black tea polyphenols, had this anti-initiating effect in varying degrees, but in general, these polymeric polyphenols in their chemopreventive properties are comparable to those shown by monomeric green tea polyphenols.

13.  Effect of Tea on Oral Mucosal Cells

Salient findings:
Following case study method and clinical studies, it is shown that consumption of black tea, one tea spoon per cup three times a day could, significantly reduce occurrences of leukoplakia. Leucoplakia is precancerous lesion in the oral mucosa and any effect that tea had in reducing its incidence will have a positive impact in reducing the level and degree of growth of cancerous cells in humans.

This apart, the micronuclei frequency was significantly low in subjects who had tea drinking habits than those without, particularly in situations arising out of arsenic contamination water.

14. Black tea as an antidote for cigarette smoke induced oxidative damage of proteins and DNA as well as cancer (II phase)

Salient findings:
Black tea extract has beneficial effects in preventing or reducing cigarette smoke induced cancer in lungs. This study has established the strong efficacy of black tea compounds in preventing the oxidative damage of protein and DNA which otherwise are destructive to lung cells, including the changes deep within the lung i.e. the emphysematous changes. It has been shown for the first time that a specific compound in cigarette smoke, P-benzosemiquinone (P-BSQ), is basically responsible for oxidative damage to proteins and DNA. Treatment of affected cells with black tea extract can reduce P-BSQ induced damage.

15. Evaluation of pro and antioxidant properties of black tea in relation to regulation of mitochondrial death cascade in cancer and immune cells

Salient findings:
Theflavins of tea initiate the apoptotic cascade in a dosage dependent manner against breast cancer. The pathway of the action basically involves utilization of an enzyme medicated box translocat to mitochondria. It has further been established the programmed death of cancerous cells following exposure to theaflavins is independent of the production of reactive oxygen species.

In depth studies of the critical pathways to apoptogenic pathway by the activity of theaflavin at cellular level suggests the potentials of theaflavins in purging the growth of cancerous cells in breast.

16. Immunomodulatory activity of Black Tea

Salient findings:
Black tea extract (BTE) displays immunomodulatory as well as immunoprophylactic activities as reflected in increases in lymphocyte counts when subjects were treated with BTE at 25 mg/kg and 50 mg/kg for 7, 15, and 48 days. The adjuvant effects include higher haemaglution titre, but BTE did not produce any significant change in lung macrophage counts.

By extrapolation it can be said that immunomodulatory activity could be beneficial under some pathophysiological conditions.

17. Stress-Hypertension and effect of tea

Salient findings:
The causal pathway to the reduction of stress hypertension in human subjects by following programmed consumption of black tea extract for 12 consecutive weeks was identified. For chronic subjects’ consumption of 450 ml of BTE, equivalent to 7.5 gms of tea leaves, during the said period caused an increase in serotonin level effecting thereby a reduction in stress level.

Despite age-specific and job specific differences in the response to BTE consumption in the distribution of neoendocrine and antioxidant enzymes, the overall impact towards stress reduction was significant.

18.  Role of tea polyphenols on the sensitivity of human leukemic cells to apoptosis

Salient findings:
This work has established the unique property of tea polyphenols in sensitizing the human leukemic cell, and the thereby prevent further spread of leukemic cells. The principal parameters used will comet assay which as a technique was proved to be reliable indicator of, apoptosis particularly in the context of application of tea polyphenols. The pathways of action of polyphenols in the initiation of apoptosis have been identified and the study indicates polyphenols could be good candidates for sensitizing tumour cell apoptosis.

Benefit to the industry

The study shows polyphenols can be an adjuvant therapy in the treatment of human leukemia. These will certainly tea industry in projecting this unique attribute of tea.

19. Antioxidant Potential of Black Tea on Prostrate Cancer - ITRC, Lucknow.

Salient findings:
Tea seems to have a remarkable effect in reducing the intensity of prostrate cancer, mostly by inhibiting the cancer promoting elements in prostrate cancer. At cellular level, these promoters operate by increasing the role of cell cycling, through prior critical cell damage followed by regeneration. Tough these mechanisms tea polyphenols exert a protective and healing effect.

Extracts containing tea compounds suppress growth the induced apoptosis largely through an increase in relative oxygen species formation and mitochondrial depolarization, although molecular mechanisms are not clear as yet.

Benefit to the Industry

  1. The findings can be used to project the strong antioxidant properties of tea.

Benefits to the Industry (for Sl. 11, 12 to 19)

These findings taken together will give a comprehensive picture of the pharmaceutical attributes of tea. The industry stands to gain by projecting the multiple effects of tea compounds against an array of human diseases.

20. Assessment of Anti-stress and aging defence activities of black tea thearubigins and theaflavins.

Salient findings : This is a very basic study. By using Drosophila as a model it looks into the mechanism of aging and stress generation, and their gene expressions in the presence and absence of thearubigins. Theorubigins are major components of black tea extract (BTE). Their impact as anti-aging and antistress agents could to a great extent be expropolated from this study to human beings.

Benefits to the industry:
This study has opened up an altogether new dimension on the beneficial effects of tea and probabilities of tea being an anti-ageing agent.

21. Study of Genotypic Predisposition to Oral Cancer modified by Tea “A collaborative study on the population of Assam.

Salient Features: This is one of the first studies with human cohorts to evaluate the potential health benefits of tea. This study took note of the anthropometric aspects of a tribal population of Assam having had various chronic oral diseases following tea dring as a therapeutic agent. It had been established that tea drinking was certainly conducive to overall improvement in the oral pathology of these human subjects, even within the limits of their highly specialized life styles and food habits in a tribal socio-ethological ambience.

Benefits to the industry:
Tea beyond doubt could be a good deterrent against oral diseases even under extreme dietary situation.

22. A study to evaluate the possible ameliorating effects of Black Tea Extract (BTE) on obesity - induced liver and bone pathophysiologic changes.

Salient Features : Using animal models it has been successfully established that liver and bone degeneration caused due to obesity could be greatly reduced by the utilization of black tea extract (BTE). BTE could even prevent decline in bone mass and volume in a characteristic way, apart from reversing functional degradation of liver cells.

Benefit to the industry
Te potential to be an agent to prevent degeneration of bone and liver under certain physiological conditions.

23.Effect of Green & Black tea extracts on Endocrine system (Thyroid-Gonadal) with possible mode of action
Salient findings:
Using specialized models of threshold level of tea flavonoids has been established for the first time. This research shows the effective levels of tea compounds for human physiological distress.

Benefit to the Industry:

This will place tea as a reliable source of overcoming some human maladies.

24. Does milk blunt the benefits of black tea

Salient findings:
The Study underpins the protective effects of tea with or without milk against hypertension. Beyond a level milk blunts the effects of black tea. A 2%addition of milk to tea is acceptable from these perspectives.

Benefit to the Industry:
This gives a new dimension to tea’s remedial attributes

25. Inhibitory role of Black Tea on Cigarette Smoke-induced Emphysema. Guinea pig model

Inhibitory role of Black Tea on Cigarette

Salient findings:
Effectivity of tea against Emphysema has been evaluated from the prospective of preventive action. The main compounds responsible for the distress have been identified, and the way tea could neutralized them have been work out.


Benefit to the Industry:
This will established the uniqueness of tea in combating smoke induced diseases




26. Studies with some chemical constituents as nutraceuticals of beverage Camellia sinensis with reference to antiulcerogenic activity and the mechanism involved

Salient findings:
Based on evidences, black tea extract and the constituent, theaflavins can  be categorized as non-toxic formulations as against the common Indian  myth of purported toxicity with restricted use, for the prevention of  NSAID induced ulceration and other inflammatory diseases by regulating   the cytokines balance and angiogenic factor

27. Studies on the protective role of black tea and mint tea against changes in the 
      endothelial function in preeclamptic women. (NTRF:17(150)/06) 

Salient findings:
The present study is the first to report the use of Mint tea ( a mixture of tea and mint)as a source of antioxidants for the treatment of preeclampsia. Both tea and mint are low in cost and are widespread. This enables the use of Mint Tea as a preventive medicine and effective dietary supplementation for the prevention and treatment of preeclampsia

This study emphasize that tea with concentration of  minimum 2% enhanced with 1.5% mint is adequate to enhance the inbuilt  antioxidant potential to combat with oxidative stress especially in conditions like preeclampsia

28. Prevention of Gastric ulceration by Black Tea: An insight into Extracellular Matrix Remodeling of gastric tissues

Salient findings:
Black Tea extracts prevent the NSAID induced Gastric Ulceration by modulation of       matrix metalloproteinase

29. Comparative Antimutagenic and Anticarconogenic effects of Black Tea Polyphenols Theaflavins, Thearubigins and the different fractions of Thearubigins in multiple test system.

Salient findings:
Findings of this study clearly indicates that both the Theaflavins (TF) and Thearubigins (TR) extracted from black tea has a significant Antimutagenic and anticancer activities. TF and TR can work against human skin cancer by inducing apoptogenic signals via mitochondria mediated pathway.

30. Evaluation of Chemopreventive efficacy of Poloymeric Black Tea Polyphenols and Mechanism(s) of their Anti-Promoting Effects

Salient findings:
Purified polymeric black tea polyphenols (PBPs) were effective in inducing both anti-initiating as well as anti-promoting activity in in vitro and / or in vivo model translocation of several PKC isoforms from cytosol to membrane is an interesting and important biological effect systems. The anti-promoting effects of PBPs are likely to be due to inhibition.

31. Multicentric Study on Effect of Tea in Cerebrovascular Disease.

Salient findings:

Tea consumption at the level of 4 cups per day reduces the risk of incidence of stroke(66%to 33%) and better control of fasting hyperglycemia and in raising the level of HDL, a good cholesterol.

32. Screening of antistress and aging defence ingredients of tea by cell Biology assays

Host Institute : University of Calcutta,

Duration : 2008-2011

Objectives :

  1. Analysis of transcriptional and translation products of the stress genes by gel electrophoresis in presence or / absence of tea polyphenols to evaluate the effectiveness of target molecules of tea polyphenols in stressful situation.
  2. Analysis of multi-stress attributes of tea-polyphenols and their interactions with the candidate genes for understanding the anti-stress attributes of TF and TR separately.
  3. To investigate and analyze the expression pattern of developmental genes whose temporal pattern of expression could be scaled as biomarkers of stress in the presence of TF or TRs.
Spermatogenesis and oogenesis in Drosophila and rat model system after oral administration tea polyphenols at different doses during development, and their implications in developmental genetics.


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