Comparative Evaluation of Neem Seed Extract as Bio-insecticide for the Control of Three Field Insect Pests of Cowpea in Maiduguri, Borno State, Arid Zone of Nigeria

Abstract

Cowpea Vigna unguiculata is an important source of nutritious food for man for healthy living and provides fodder to the animal for optimum production and grows in the ecological part of Nigeria. However, despite its importance to man and national development, its main cultivation challenge is insect pests which sometimes account for as high as 40 % loss in production. The continuous use of conventional insecticides to control pests is resulting in unbearable health hazards, hence the need for alternative control measures such as the use of botanicals. This study evaluated the efficacy of neem seed extract biopesticide compared to cypermethrin synthetic insecticide for the management of Thrips, Maruca vitrata and Clavigralla tomentosicollis on cowpea varieties in Maiduguri, Borno State of Nigeria. The neem seed extract was extracted following standard procedures and used as a treatment alongside cypermethrin against the three pests at weekly intervals on four cowpea varieties. Pest population buildup was monitored for five weeks on treated and untreated (control) crops beginning from 24 hours after each treatment on weekly bases. The result revealed a significant reduction (P>0.05) in the population buildup of the three pests on both neem seed oil and cypermethrin-treated crops compared to the control. No significant difference (P>0.05) in population reduction was observed between crops treated with neem seed extract and Cypermethrin. Consequently, there was a significant increase in the grain yield of cowpea on treated plots compared to untreated plots. The neem seed extract has demonstrated a high potential substitute for synthetic insecticide to control the three insect pests.