Surveillance of pest population on different non-scented and scented rice cultivars under changing management scenario

Abstract

A field survey on 10 non-scented and 4 scented rice varieties to observe the incidence of different major pest species as well as parasites and predators (natural enemies) of rice at fortnightly interval was undertaken at Majhian, Dakshin Dinajpur district. The result revealed that Scirpophaga incertulas (rice stem borer) and Nephotettix spp., Cofana spp. and Nilaparvata lugens (hopper complex) were maximum during September – October whereas population of leaf folder was maximum in the month of October at vegetative stage and Leptocorisa spp. was maximum during October- November at flowering and milky stage. The highest leaf folder (Cnaphalocrocis medinalis) population was recorded on Sawrna Sub-1 (2 folded leaf with larva/hill) and the population of the pest was suppressed by Apantellis sp. (pupal mass 1/5hills on an avg. and adult emergence was 18.74/pupal mass). The natural enemy population both on non scented and scented rice cultivars was 0.07-0.16 and 0.05-1.81, respectively.