Bio-efficacy of Chlorantraniliprole (Rynaxypyr) 20 Sc Against Yellow Stem Borer, Scirpophaga Incertulas (Walker) and Leaf Folder, Cnaphalocrocis Medina/is (Guenee) in Rice

Abstract

An investigation was carried out to study the bio-efficacy of chlorantraniliprole (Rynaxypyr) 20 SC against yellow stem borer, Scilpophaga incertulas (Walker) and leaf folder, Cnaphalocrocis medina/is (Guenee) in rice during Kharif 2014 at Crop Research Centre of Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut, in a randomized block design with eight treatments and three replications. During the crop season, 12 insect species were found attacking on basmati rice at different crop growth stages. Among them, yellow stem borer, S. incertulas (Walker) and leaf folder, C. medina/is (Guenee) were recorded as major pests. The first infestation of yellow stem borer was recorded on first week of August and reached its peak during middle of October when average temperature, relative humidity and rainfall ranged from 27.10 to 30.51 °C, 69.60 to 84.04% and 0.30 to 7.56 mm, respectively. The population of leaf folder was first recorded in last week of July and reached at maximum level during end of September to start of October when mean temperature, relative humidity and rainfall were 28.89 °C and 76.95 %, respectively. The population of yellow stem borer and leaf folder showed negative correlation with maximum and minimum temperatures, evening relative humidity and rainfall while morning relative humidity showed the positive correlation. Efficacy of different treatments of chlorantraniliprole and cartap hydrochloride, trizophos and chlorpyriphos against yellow stem borer and leaf folder revealed that all the treatments were found significantly effective in reducing the infestation and increasing the yield as compared to control. The most effective treatment in reducing the infestation of both the insects was chlorantraniliprole 20 SC @ 180 ml/ha followed by chlorantraniliprole 20 SC @ 150 ml/ha. The chlorpyriphos@ 1000 ml/ha was recorded Jess effective. The highest yield (40.35 q/ha) and cost benefit ratio (I :3.49) were also obtained from treatment chlorantraniliprole 20SC @ 180ml/ha.