Control of fruit borer of garden egg Leucinodes orbonalis (Lepidoptera: Pyralidae) using organic and inorganic pesticides

Abstract

Field experiments were conducted at Michael Okpara University of Agriculture, Umudike, Nigeria during 2007 and 2008 cropping seasons to determine the efficacy of Garlic Ethanolic Extract (GEE), Kerosene Soap Emulsion (KSE) and Lambda-Cyhalothrin in the control of the population of garden egg fruit borer Leucinodes orbonalis Guenée and on some of the yield components of the crop. The treatments were laid out in a Completely Randomized Block Design (CRBD) with three replicates and applied at low concentrations of 0, 1, 2, 3 and 4%, respectively. The results obtained showed that all treatments exhibited varying degrees of pesticidal efficacy, as their application significantly reduced the population of the fruit borer (P ≤ 0.05). However, plots treated with Lambda-cyhalothrin recorded the least number of L. orbonalis (2.00 larvas per plant and 1.30 larvas per plant in 2007 and 2008 respectively). This result was closely followed by GEE at 3 and 4% concentrations (3.67 larvas and 3.3 larvas per plant in 2007, and 2.13 larvas and 1.70 larvas per plant in 2008 cropping seasons respectively). Application of Lambda-cyhalothrin produced the highest mean number of fruits (56.20 fruits per plant) in 2007, compared to other treatments with the resultant higher fruit weight of 1.44 kg/plant. The highest fruit yields of 900 and 793.75 kg/ha were obtained from plots sprayed with Lambda-cyhalothrin in 2007 and 2008 respectively and followed by 687.50 kg/ha obtained in plots treated with 4% GEE. The results of this trial indicated that plant-derived pesticides are promising as alternatives to synthetic pesticides which are hazardous to human health and environment in the control of the garden egg fruit borer.

Keywords: Garden egg, fruit borer, garlic ethanolic extract, kerosene-soap emulsion, Leucinodes orbonalis, plant extract.