Evaluation of Microbial and Chemical Insecticides Against Yellow Stem Borer, Scirpophaga Incertulas (Walker) and Leaf Folder, Cnaphalocrocjs Medinalis (Guenee) Of Basmati Rice

Abstract

An investigation was carried out to study the ''Evaluation of microbial and chemical insecticides against yellow stem borer, Scirpophaga incertulas (Walker) and leaf folder, Cnaphalocrocis medina/is (Guenee) of basmati rice" in randomized block design with three replications at Crop Research Centre of Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut ·during Kharif 2013. During the crop season, ten insect species were found attacking the basmati rice at different crop growth stages. Among them, rice stem borer, Scirpophaga incertulas (Walker) and rice leaf folder, · Cnaphalocrocis medina/is (Guenee) were recorded as major pests. The gundi bug, Leptocorisa acuta (Thumb) and brown plant hopper, Nilaparvata lugens (Stat) were found moderately damaging the crop. Yellow stem borer incidence appeared first in the first fortnight of August whereac; leaf folder incidence appeared in the second fortnight of July and continued till the harvest of crop. The dead heart/white ear head per cent increased from September first week and reached to its peak in October. Whereas the damaged leaf per cent increased from August . and reached to its peak in September. Abiotic factors showed positive correlation with maX.imum temperature and negative correlation with minimum temperature, relative humidity and rainfall for both pests. · Efficacy of different insecticides viz., cartap hydrochloride 50 SP, fipronil 5 EC, lambda cyhalothrin 5 EC, spinosad 45 SC, indoxacarb 14.5 SC, chlorpyriphos 20 EC and biopesticides viz. Beauveria bassiana and Metarhizium anisopliae tested against S. incertulas and C. medina/is revealed that spinosad 45 SC @ 150 ml/ha was found most effective treatment in reducing the population of both pests followed by cartap hydrochloride 50 SP @ 1.0 Kg/ha. The biopestici~es Beauveria bassiana ~nd ~/etar~i~ium anisopliae @ 2.5 kg/ha were recorded less effective as compar~ to chemical msectlc~de~. The higher yield was obtained from spinosad 45 SC whereas, highest cost benefit ratto ts obtained from cartap hydrochloride 50 SP.