Effects of Cultivars and Insecticides on Fruit Loss caused by Eublemma olivacea in Eggplant in Biu, Borno State, Nigeria

Abstract

Field trials were conducted at Biu (latitude 10°35’N and longitude 12° 13’N and 750 m above sea level) during the 2008 and 2009 rainy seasons to study the reaction of three cultivars of eggplants to insecticide sprays against Eublemma olivacea (walk) infestation. The factorial experiment consisted of three local eggplant cultivars (Biu Stripped, Biu White, and Biu Green), two insecticides {Endosulfan and Neem Seed Aqueous Extract (NSAE)} and three spray regimes {at 2 weeks after transplanting (WAT), 2 and 4 WAT and at 2,4 and 8 WAT}. Among the three cultivars (Biu Green, Biu stripe and Biu White), Biu Green (BG) showed some degree of resistance to the larvae and had higher fruit yield which makes it the best cultivar. Untreated cultivars had significantly higher number of larvae and higher percentage fruit damage in both 2008 and 2009 rainy seasons. Both Endosulfan and NSAE were better than the control. NSAE performed better in terms of fruit yield and therefore the best insecticide for safer and higher fruit yield. The results also showed that three sprays significantly lowered the number of larvae per plant/plot. The larvae of Eublemma olivacea was found to be damaging young fruits and leave of eggplant in the area. Based on the outcome of this study, farmers can spray their eggplant three times with NSAE for a better fruits yield.