Efficacy of Seed Treatment and Seedling Root Dip with Insecticides against Rice Leaf Folder (Cnaphalocrocis medinalis Guenee)

Abstract

Rice leaf folder, (Cnaphalocrocis medinalis) is a major insect pest of rice in India inflicting extensive yield losses. The present study was undertaken to study the efficacy of seed treatment and seedling root dip treatment with newer insecticides to find scalable and practical methods for its management. A field experiment was conducted at ICAR-Indian Institute of Rice Research, Hyderabad during the Kharif season of the year 2024-25 in a Randomized Complete Block Design with 13 treatments. Data on the per cent damaged leaves by leaf folder per hill were recorded at 30 days after transplanting and were subjected to two-way ANOVA. Means were separated by LSD at 5 per cent level of significance. The results revealed that seed treatment with thiamethoxam was the most effective with significantly lower damaged leaves (10.94%) followed by seedling root dip with carbosulfan (12.1%) as compared to the untreated control (20.78%). These results demonstrate the outstanding efficacy of the seed treatment with thiamethoxam and seedling root dip with carbosulfan that are of immediate practical importance to the growers and hold potential of lessening the number of insecticide foliar sprays required at subsequent growth phases of rice crop leading to reduction of  insecticide load in the rice crop ecosystem.