Agronomic practice influence dry matter production and favourable partitioning in tea. On field transfer, young tea plants showed growth inhibition due to apical dominance. When the apical meristem is removed by means of centering, dormant buds grow out and form new shoots. Growth retardants suppress apical dominance and induce the growth of latent buds without hindering the metabolic activities of the plant. Centering of young tea plants four to five months after planting is advantageous in promoting an early spread. Newly formed shoots allowed to grow freely are tipped at determined heights. Tipping enhanced effective canalization of assimilates in terms of root carbohydrates. The axillary and the accessory buds formed after two stage tipping contribute to canopy formation.
Pruning reduced the leaf area index drastically and the balance between the growth of shoots and roots is disturbed. The recovery of tea bush from pruning depends upon health of the bushes in terms of root carbohydrates. It also influences the favourable partitioning of dry matter in tea. A significant increase in promoter:inhibitor ratio was also observed on the application of Plant growth regulators (PGRs) which reduced the banji (dormant shoots) percentage significantly.
Tea plants have a rythemic growth pattern, dormancy and flush, coinciding with either management practice or unfavorable environmental conditions or a combination of both. Environmental conditions regulate the levels of endogenous promoter inhibitor ratio in the plant system. Plucking system determines the amount of maintenance foliage left on the bush. Continuous mother leaf plucking resulted in lower yield and retained excessive maintenance foliage. Harder form of plucking though resulted in higher crop, affected the ratio between the leaf and stem. Harvesting to mother leaf through dry spell led to sustained crop ensuring the normal metabolic functions.
Photosynthetically active functional units of the tea bush are considered for gross productivity. Continuous use of shears for harvesting in tea led to crop loss due to the physiological imbalance which in turn adversely affected the bush health. Photosynthetic rate declined due to the damage caused by shears on the maintenance leaf thereby affecting the metabolic activity significantly.
Increase in the abscisic acid content tilted the promoter:inhibitor ratio towards inhibitor side which in turn influenced the formation of dormant buds in tea. More number of banji shoots in the harvest, not only affects the productivity; they also deteriorate the quality of made tea to an extent. Responses of tea plants to applied plant growth regulator are encouraging. An increase in economic yield was noticed when plants were applied with commercial plant growth regulators without affecting either the quality or bush health. Foliar application of NK and antitranspirants imparts drought tolerance, sustaining physiological activities by regulating balanced water relations.
Tea leaves attain their peak efficiency in photosynthesis when fully expanded and remain photosynthetically active for longer period. A quadratic relationship existed between the age of a tea leaf and net photosynthetic rate. A progressive increase in photosynthetic rate was recorded for four months and then declined.
As the axillary bud unfolded the sink capacity decreased while the photosynthetic carbon assimilation capacity of maintenance leaf increased. There was a significant increase in photosynthetic efficiency from bud to fully expanded leaves. Expanding second and third leaves show a significant variation in fixing atmospheric carbon dioxide. One leaf and a bud showed a significantly higher sink capacity than two or three leaves and a bud. Plucking three leaves and a bud along with banjis seems to be the ideal standard which facilitates sink-induced photosynthesis, in turn enhancing productivity index.
As the distance between the “source” and “sink” increased, a substantial reduction in the mobilisation of photosynthates was noticed. Several factors were found to influence their mobilisation. When the photosynthetic rate increases the amount of assimilates translocated to the sink also increased dramatically. The maintenance leaves below 20 cm of the canopy would not be disadvantageous per se, but the synthesis and maintenance of superfluous amounts of photosynthates would require an increased expenditure of energy.
Pruning reduced the leaf area index drastically and the balance between the growth of shoots and roots is disturbed. The recovery of tea bush from pruning depends upon health of the bushes in terms of root carbohydrates. It also influence the favourable partitioning of dry matter in tea. A significant increase in promoter:inhibitor ratio was also observed on the application of Plant growth regulators (PGRs) which reduced the banji (dormant shoots) percentage significantly.
News & Events
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MRL’s OF AGROCHEMICALS ON TEA IN DIFFERENT COUNTRIES/ORGANIZATIONS AS ON JANUARY 2021
updated in Jan 2021 MRL
Read MoreVACANCY 2022
18.10.2022
Senior Research Fellow position for the project : Field evaluation of four Bioproducts of Green Harvest (India) Bio-Tech Private Limited Wanted a post graduate in Zoology or Entomology for a Senior Research Fellow for a period of one year. Interested candidates may apply within 15…
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Dr. C.S. Venkata Ram Memorial Annual Tea Colloquium
Dr. C.S. Venkata Ram Memorial Annual Tea Colloquium will be announced later.
Read MoreResidue analysis in other crops
31-05-2013
The Pesticide Residue Division is equipped with state-of-art instruments viz., Gas Chromatograph, High Performance Liquid Chromatograph, GCMS, Atomic Absorption Spectrophotometer, etc., Our lab is GLP certified by National GLP Compliance Monitoring Authority, Govt. of India for the execution of Pesticide Residue Studies. We are accredited…
Read MoreMonthly circular – April 2014
07/04/2014
Monthly Circular April -2014 WEATHER Weather data recorded in March 2014 at the TRF observatory are given below, along with the corresponding figures for March 2013. Year Total Rainfall mm Mean Sunshine hr/day Mean Temperature ° C Mean Relative Humidity % at Mean Evaporation…
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Articles
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Publications
Radhakrishnan,B., K. K. Srikumar, Smitha, K. B. Suresh. 2018. Evaluation of Sulfoxaflor 50%WG against Tea mosquito bug, Helopeltistheivora Waterhouse (Hemiptera: Miridae). Pestology. 42 (3), 31-36. Radhakrishnan, B. 2018. Recent issues on pesticide residues and other contaminants in Tea. Planters chronicle. 114(1): 4-11. Radhakrishnan B. and…
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12/12/12
The principal landmark in the history of tea research in south India, was the establishment of a Tea Experimental Station in Gudalur in 1926. During the last seven and half decades, this research organisation. Now known as the UPASI Tea Research Foundation (UPASI TRF), had…
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01/02/05
Annual Report is the one among the major publications of UPASI TRF. Annual report of each year is released by September of the following year. Other publications include Research Highlights and half yearly Newsletters. The Bulletin of UPASI TRF is an occasional publication. The Handbook…
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Conferences Seminars
12National Symposium Announcement
DATE: 22nd Jannuary, 2021
PLACE:
Read MorePLACROSYM XXI
DATE: 10-12 December 2014
PLACE: Kozhikode
Read MoreResearch Extension Meeting
DATE: 06-08 May 2013
PLACE: Valparai
Read MoreJOINT AREA SCIENTIFIC SYMPOSIA (JASS)
DATE:
PLACE:
Read MoreINTERNATIONAL TEA CONVENTION
DATE:
PLACE:
Read MoreTGLIA
DATE: 2013
PLACE:
Read MoreDr.C.S. Venkata Ram Annual Tea Colloquium
DATE: 1 August 2013
PLACE: VALPARAI
Read MoreINTERACTIVE SESSIONS / WORKSHOPS
DATE: 28/04/2012
PLACE: VALPARAI
Read MorePLATINUM JUBILEE SYMPOSIUM
DATE: 2001
PLACE: Chennai
Read MorePLANTATION CROPS SYMPOSIUM 2014
DATE: 2014
PLACE:
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Research Activities
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Pesticide Residue
Of late, considering the constant usage of pesticides and to monitor the residues in the final produce, a well equipped test facility was established at UPASI TRI in 1994. The pesticide residue laboratory is accredited by National Accreditation Board for testing and calibration Laboratories (NABL)…
Read MoreBotany
The Tea Research Institute at Valparai has seven divisions namely Botany, Soil Chemistry, Entomology, Pesticide Residue, Plant Pathology & Microbiology, Plant Physiology & Biotechnology and Tea Technology. Botany Research activities of Botany Division include plant improvement, cultivation practices and weed research. Plant improvement programme was…
Read MoreSoil Chemistry
Chemistry Division is involved in research pertaining to soil-plant nutrients of tea besides extending analytical service to the industry. The research activities include investigations on physico-chemical properties of soil, soil-plant interactions, response of tea to major, secondary and micronutrients and their interactions. The research work…
Read MoreEntomology
Entomology Division involve in basic and applied aspects of insect pests, particularly, biology, ecology and evolving control measures. The division evolved and recommended physical, chemical and biological method of tea pests control. In the past, extensive studies on bioecology, crop loss due to major pests…
Read MorePathology & Microbiology
In the division of Plant Pathology & Microbiology, research is carried out on diseases of tea and biofertilizers. Among the tea diseases, blister blight is the most important leaf disease caused by the pathogen, Exobasidium vexans affecting the tender harvestable shoots of tea resulting in…
Read MorePhysiology & Biotechnology
Plant Physiology Division was established in 1980 which has been primarily concentrated on crop productivity. The division strives for excellence in applied research in tea productivity and bush health besides biotechnological studies. The research undertaken extends over a wide range of research programmes having collaborative…
Read MoreTea Technology
Besides offering the analytical services and involving in inter laboratory ring test to validate the test methods, Tea Technology Division is concerned about quality of final produce in accordance with PFA Act requirements, storage studies, value added products and manufacturing aspects. The laboratory has been…
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