Evaluation of Sugarcane Genotypes Against top Borer, Scirpophaga Excerptalis and Relation with Environmental Factors

The sugarcane top borer Scirpophaga excerptalis (Walker) causes significant damage to sugarcane (Saccharum spp.) crop in India. For environmental and economic concerns, the cultivar resistance is the most viable option. Keeping this in view, evaluation of 133 sugarcane genotypes was conducted for their reaction against the top borer and its incidence was related with the meteorological parameters. The cumulative incidence ranged from 0.53 (Sel 22–01) to 31.72 (Sel 1046–03). Thirty genotypes showed less than five per cent cumulative top border incidence, which were rated as comparatively resistant genotypes while nineteen genotypes showed more than 15 per cent incidence and these were rated as comparatively less resistant genotypes. On comparison of the climate factors with the incidence of the pest in different years it was observed that there was more rainfall during 2005–06 as compared with other years of study, which might be related to high borer incidence in this year. Temperature and rainfall remained similar in investigation years.