Comparing efficacy of selected biopesticides and Lambdacot 500EC for controlling leaf rollers in eggplant (Solanum melongena L.)

Abstract

Field experiments were conducted during the 2012 and 2013 cropping seasons at the University of Maiduguri to compared the efficacies of selected aqueous plant extracts on the management of the population of eggplant leaf roller (Eublemma olivacea Wlk.) infesting eggplant (Solanum melongena L.). The extracts were from neem leaf; bitter melon; black current; ginger rhizome and wild onion. They were compared with a conventional insecticide, Lambdacot 500EC and the absolute control. Extracts were applied at 5 % w/v while Lambdacot was applied at 1.5 g a.i/ha. The results indicated that the mean number of leaf rollers in treated plots were significantly (P< 0.05) lower than the control. The highest mean number of leaf rollers was 3.01 and 3.93. Lambdacot 500 EC had the lowest eggplant leaf roller counts per plant followed by neem, ginger rhizome and wild onion. The mean number of leaves damaged per plant followed similar trend. There was significantly (P< 0.05) higher number of eggplant fruits/plant, fruit weight and fruit yield in the decreasing order of Lambdacot 500 EC, neem, wild onion, bitter melon and black current. The absolute control had the fewest number of eggplant fruits/plant, fruit weight and fruit yield. These aqueous extracts should be adopted by eggplant farmers as they are cost effective and friendly to the environment. However, the actual quantities of these extracts to be applied per plant depending on the variety of eggplant, season and weather condition of the cropping season and canopy architecture remain to be critically explored.