Abstract

                                The incidence of pests and diseases is closely knit with the prevailing weather conditions. With a view to understand the nature of such influence, experiments were started in 1954, in the four irrigated crops of cholam, ragi, cotton and groundnut raised at the Central Farm, Coimbatore. From the date of sowing to the date of harvest, micro-climatic observations were recorded amidst the crops both morning and evening at stipulated hours and also weekly observations on pests in collaboration with the Entomologist, Coimbatore. The data so collected for fourteen years from 1954 to 1967 in CO.12 irrigated cholam raised as a summer crop at Coimbatore were examined with particular reference to stem borer, Chilo zonellus, S., which is a major pest of jowar, maize and sugarcane and also at times bajra and rice (Trehan and Butani, 1949), together with the macro-climatic observations recorded at Agricultura! Meteorological Observatory, Agricultural College and Research Institute, Coimbatore.

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