SOME ECOLOGICAL FACTORS ON POPULATION DYNAMICS OF RED SPIDER MITE (OLIGONYCHUS COFFEAE, NIETNER ) AND THEIR CONTROL IN THE TEA AGRO-ECOSYSTEM OF BARAK VALLEY, ASSAM (INDIA)

Abstract

Mites are serious pests of tea known since the early days in all the tea growing areas/countries. They damage the green tissues and affect photosynthesis, causing reduction in yield. In the present study, varied severity of damage caused by Red Spider Mite (Oligonychus coffeae, Nietner) was observed in different tea growing sub areas of Barak Valley, south Assam. The pest population was found to be seasonally variable and dependent on the prevailing agroclimatic conditions (viz. temperature, rainfall etc.). Some of the clonal tea varieties were highly susceptible to red spider mite, some were moderate and others were fairly resistant.
Amongst the inorganic pesticides, a mixture of Ethion and Sulfex controlled the pest reasonably well. Of the organic pesticides, the neem-based products showed good control of the pest. A mixture of a neem based product (viz. Neemox) and Ethion gave an excellent control of the mite. Prophylactic sprays with organic and inorganic chemicals during the winter months (December February) helped to considerably reduce the carried-over population of red spider mite, and consequently reduced the degree of infestation in the subsequent years.