Evaluation of insecticides against shoot and fruit borer Leucinodes orbonalis on brinjal at Tamil Nadu

Abstract

The roving survey was undertaken in major brinjal growing areas of Tamil Nadu viz., Coimbatore, Erode, Dindigul, Madurai and Thirunelveli to study the insecticide use pattern to control brinjal shoot and fruit borer, L. orbonalis revealed that, 18 different insecticides were frequently used to manage the target pest. The average number of spraying in one season was maximum in Dindigul (12 to 15) followed by Coimbatore (10 to 12), Thirunelveli (8 to 10), Erode (8 to 10) and Madurai (7 to 9). Usage of power sprayer maximum in all the five locations. Based on the survey result, eight insecticides viz., chlorpyriphos, dimethoate, quinalphos, thiacloprid, emamectin benzoate, flubendiamide, thiodicarb and lambda-cyhalothrin were identified as prominently used insecticides to manage L. orbonalis in all locations, which were evaluated for its bioefficacy against target pest in the field condition. After two rounds of spray, the significant shoot damage reduction was observed in plots treated with thiacloprid 21.7 SC at 180 g a.i. ha-1 (95.47%) and flubendiamide 480 SC at 48 g a.i. ha-1 (92.00%) followed by lambda-cyhalothrin 5 EC at 15 g a.i. ha-1 (87.78%), emamectin benzoate 5 SG @ 10 g a.i. ha-1 (87.23%) and thiodicarb 75 WP at 750 g a.i. ha-1 (86.76%) in the first trial conducted at Thondamuthur during June to August 2016. Same trend was observed in the second field trial conducted at semmedu, during July to September 2016. In both the trials untreated check recorded the highest per cent shoot damage in all the days of observation. In terms of fruit damage, the plots treated with thiacloprid 21.7 SC at 180 g a.i. ha-1 received the highest per cent reduction over control followed by flubendiamide 480 SC at 48 g a.i. ha-1 lambda-cyhalothrin 5 EC at 15 g a.i. ha-1, emamectin benzoate 5 SG @ 10 g a.i. ha-1 and thiodicarb 75 WP at 750 g a.i. ha-1 which were on par with each other in both trials.