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 such as shot hole borer (SHB), mites and Helopeltis and its control measures were carried out. Crop loss assessment due to pest incidence and economic threshold levels of tea pest were documented.
Several new acaricides/insecticides, bio-pesticides and insect growth regulators were screened from time to time for their bioefficacy against target pests, impact on natural enemies in tea ecosystem, pesticides, taint and phytotoxicity.
Most of the tea pests are highly seasonal; many attack tea only in dry season while a few are abundant in wet weather; there are a few perennial pests too. Data are available on the bioecology and crop loss caused by major pests such as pink and purple mites, thrips, tea mosquito and SHB. Red spider mite (RSM), Oligonychus coffeae has emerged as an important pest of tea in the last few years. Studies on its population ecology showed that the incidence of RSM was high during January to May and low during June to December. Populations reached a peak in March / April. Studies revealed that the mite can cause more than 18 % loss in crop when the infestation is severe.
Certain cultural operations like plucking, pruning, shade regulation and weed control can be manipulated to reduce the incidence of pests. Populations of leaf folding caterpillars such as flushworms and leaf rollers can be suppressed by manual removal during harvest. Tea mosquito laid eggs on the broken ends (stalks) of plucked shoots. Intensive removal of stalks during plucking will reduce the incidence of this pest. Weeds offer excellent hiding places and serve as alternate hosts for Helopeltis. Growth of weeds/wild host plants in and around tea fields may be controlled which will help to reduce the incidence of tea mosquito. Severity of attack by SHB increases with the age of the field from pruning. Hence, it was recommended to maintain the length of pruning cycles to 4 years in mid elevation areas. Soil application of higher rate of N:K2O @ 1:2 ratio in the first year of pruning cycle significantly reduced the SHB infestation.
The division’s multifaceted research involves biological control in terms of exploiting natural enemies and use of biological compounds to reduce the pesticide load. Neem oil, neem kernel aqueous extract, commercial formulations based on azadirachtin with or without adjuvants and botanical extracts are being evaluated against RSM. Formulations containing azadirachtin have been found effective against pink and purple mites and caterpillar pests such as flushworms and leaf rollers. Use of these neem formulations are recommended mainly to save natural enemies and to reduce the load of synthetic pesticides on tea. Although the knockdown effect is not reported in the neem products, it may act as a strong repellent, feeding inhibitor and growth inhibitor, ovicidal and ovipositional deterrent against insect pests. With the help of a project funded by the ministry of Chemicals and Fertilizers, Govt. of India, neem kernel aqueous extract (NKAE) was evaluated against the red spider mite, leaf roller, flushworm and tea mosquito infesting tea. Results indicated that NKAE @ 5.0% concentration was effective against red spider mite while application of NKAE significantly reduced the population build-up of leaf roller and flushworm when compared to untreated control. NKAE @ 5% concentration was not effective against tea mosquito. NKAE was not phytotoxic to tea and did not impart any undesirable taint to made tea.
During the last one decade, considerable efforts have been made to incorporate non-chemical control strategies and to evolve an integrated pest management programme for tea. Minor status of many of the tea pests is mainly due to the influence of the biocontrol agents. So far, more than one hundred species of predatory and parasitic insects and mites have been reported from the tea estates of southern India. Scientist realized the role of biological control agents in regulation of tea pests and generated extensive data on bioecology of major parasitoids and predators. Effect of egg parasitoid of tea mosquito and predators of red spider mites were already documented. However, at present biology and life table studies of the predatory mite, Neoseiulus logispinosus on RSM were initiated. Similarly, a mass rearing technique of green lace wing (Mallada boninensis), a predator of RSM was standardized under laboratory conditions.
Identification and exploitation of semio-chemical/sex pheromones is yet another area of research in pest management. Research on semio-chemicals using electro antennogram proved that the partially dried bark of Montanoa bipinnatifida (jungle plant commonly known as December flower) contains volatiles which can attract the SHB. Number of beetles attracted to the stem trap was more during June to October with a peak in July. Number of beetles attracted to the stems declined 15 to 20 days, after placement, indicating the need for their replacement. Scientists identified the volatiles using GC-MS and identified economically feasible commercial chemical blends besides optimization of trap blend, dispenser and number of traps per unit area for the control of SHB.
At present, studies on sex pheromones of tea mosquito are in progress. Volatile compounds released by the unmated females were extracted and subjected to GC-MS analysis. Compounds involved in the attraction and their composition were recognized. Olfactory chemo sensilla situated in the antennae of the tea mosquito showed largest response to certain mixtures in Electro Antennogram (EAG).
Evaluation of new molecule of pesticides, pesticide resistance and microbial control of tea pests are certain other major area of research where the association among the fungi, bacteria and viruses with various pest species are established. This area of research enabled the TRI to identify an isolate of Beauveria bassiana infesting the shot hole borer and pave the way to development of wettable powder formulation for the control of SHB which has been commercialized in the recent past. Bacteria, Pseudomonas fluorescence, isolated from tea soils identified as a potential biocontrol agent against control of RSM and commercialized. Sulphur formulations are effective against all types of mites, including RSM. Paraffinic oil was found effective against red spider mites. Since this oil does not leave any residues in tea, it is incorporated into the mite control programme in tea and in organic tea gardens. Extensive studies are in progress under IPDM programme.
Monitoring the pesticide resistance status of RSM and tea mosquito of south India has been initiated where the LC50 values of field collected and laboratory reared (>25 generations) mites against commonly used pesticide were established. Investigations on the integration of cultural and chemical control of tea mosquito are also in progress for evolving an economically feasible management programme against this pest. On the whole, the division’s pest management strategy involving cultural, physical, chemical and biological control measures is well received by the planters.
News & Events11
Preharvest-interval re-commendedby-UPASI-TRF-TRI-Updated-on-1FEB-2021Read More
updated in Jan 2021 MRLRead More
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Dr. C.S. Venkata Ram Memorial Annual Tea Colloquium will be announced later.Read More
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 More
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…Read More
News Letter -2020 JuneRead More
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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…Read More
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…Read More
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…Read More
National Symposium Announcement
DATE: 22nd Jannuary, 2021
DATE: 10-12 December 2014
PLACE: KozhikodeRead More
Research Extension Meeting
DATE: 06-08 May 2013
PLACE: ValparaiRead More
JOINT AREA SCIENTIFIC SYMPOSIA (JASS)
INTERNATIONAL TEA CONVENTION
Dr.C.S. Venkata Ram Annual Tea Colloquium
DATE: 1 August 2013
PLACE: VALPARAIRead More
INTERACTIVE SESSIONS / WORKSHOPS
PLACE: VALPARAIRead More
PLATINUM JUBILEE SYMPOSIUM
PLACE: ChennaiRead More
PLANTATION CROPS SYMPOSIUM 2014
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Newsletter – Dec 2019Read More
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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 More
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 More
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 More
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 More
Pathology & 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 More
Physiology & 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 More