(International Society of Tea Science (ISTS), 2004) Wahab, S.; Jain, N.K.
The increasing demand for higher productivity of tea, results in its intensive cultivation, which increases the pressure from insect pests on this crop. Chemical pesticides, irrespective of their toxicity status, are being extensively applied. Their various detrimental effects become apparent in the ecosystem including residues in made tea. Bio-control agents such as parasites, predators, and fungal, bacterial and viral pathogens have strong potential to act as effective alternatives to chemical pesticides. In this paper, an attempt has been made to compile all available information on biocontrol research on tea around the world as well as in lndia. This information will not only help to focus the possibility of using these agents against tea pests, but also will identify the gap of biopesticidal research for designing the future thrusts. Department of Biotechnology Government of lndia has played a catalytic role and supported several projects on the management of tea pests and diseases in Indian tea.
(International Society of Tea Science (ISTS), 2004) Han, B.; Dong, W.; Cui, L.; Jain, N.K.
Several insecticides, germicides and herbicides which, are now prohibited, are still used in Chinese common tea gardens. Applied amounts of the pesticides with high toxicity and long time residues, such as methomyl, cannot bypass certain limits in A-grade green food tea gardens. Pesticides are forbidden to be used in AA-grade green food tea gardens and organic tea gardens. Pesticide residues in a large number of merchant teas exceeded the national standard during 1998 - 2001. According to national standard, the number of samples exceeding standard percentage of 4200 output tea samples (including green tea, black tea, scented tea and oolong tea) in 2001 reached 6.55 %. However; the exceeding standard percentage was 0.4 % for 228 output tea samples in 2002. Safety time internal, half-life and MRL values of main pesticides used in Chinese tea gardens have been now introduced. The application of natural enemy insects, spiders and pathogenic microorganisms in biological control has also been summarized. 119 Species of main natural enemy insects have been recorded. The joint application of insect semiochemicals and pathogenic microbes, the approach to chemical mechanism of tea plant resistance to pests and disease causing organisms by physiological and biochemical techniques, and tea breeding against pests and diseases by molecular biological techniques will be the key research fields of biocontrol of tea pests and diseases in China in the near future.
(International Society of Tea Science (ISTS), 2004) Ramarethinam, S.; Marimuthu, S.; Murugesan, N.V.; Jain, N.K.
Chemicalisation of agriculture in general and tea in particular results in chemical residues in the finished product. Due to stringent MRL values fixed for various pesticides in made tea, and the difficulties in marketing of such produce, chemicalisation of tea cultivation is now getting reduced. Diversification of tea-based produce as value added therapeutics and cosmetics is also paving way for organic tea farming. This situation necessitated introducing nature's friendly methods of tea cultivation with 'ecofriendly' products as a major input for plant protection and production. Neem with its multiple biological effects, like antifeedant, repellent, oviposition deterrent, growth regulation and its environment-friendly nature, is a handy tool to control insect pests in tea. The present article is focused on the positive role of neem and its derivatives in controlling tea pests in an ecofriendly way.
(International Society of Tea Science (ISTS), 2004) Banerjee, B.; Jain, N.K.
Natural enemies of tea pests have co-evolved with their preys. Most have a fairly low level of satiation and, therefore, may not control the pests in the conventional sense. They do, however, regulate the pest population to prevent large scale outbreaks. In the absence of natural enemies the pests may become endemic.
(International Society of Tea Science (ISTS), 2004) Ellison, C.A.
Tea (Camellia sinensis) is particularly susceptible to competition by weeds, and implementation of controlpractices requires considerable inputs from the farmer. Biological control (BC) using fungal natural enemies offers a sustainable, environmentally friendly and cost effective alternative strategy for the control of weeds. Two approaches can be considered in this strategy: classical biological control (CBC) of invasive alien weeds using their coevolved natural enemies, from the centre of origin of the weed; and inundative control using those pathogens that can be mass-produced, and which are already present in the country where the weed is a problem. The BC potential of 22 important weeds in tea in Asia is presented; it includes four weeds where CBC has already been successfully implemented somewhere in the world. A case study on the CBC of the invasive alien weed Mikania rnicrantha, using the coevolved rust fungus Puccinia spegauinii (from Latin America), in the Assam tea-growing region of India is discussed.
