FIELD EVALUATION OF THREE MICROBIALS AND TWO BOTANICALS AGAINST INFESTATION AND DAMAGE BY TWO KEY FIELD INSECT PESTS OF COWPEA (VIGNA UNGUICULATA (L.) WALP.) IN KANO, NIGERIA

Abstract

Field experiment was conducted during the 2021 and 2022 cropping seasons at the Teaching and Research Farm of the Centre for Dryland Agriculture (CDA), Bayero University, Kano. The aim was to evaluate the performance of two botanicals viz:- Neemsol GA (Azadirachtin) and Zeropest GA (Karanjin) and three microbial insecticides viz:- Powerfist GA (Lecanicillium muscarium), Fixit GA (Beauveria bassiana) and Freeze GA (Hirsutella sp.) tested along-side a synthetic insecticide (Imidacloprid) the management of cowpea flower thrips (Megalorothrips sjostedti) and pod borer (Maruca vitrata) on a medium maturing cowpea variety IT99K-573-1-1. Results showed that, Powerfist GA, followed by Neemsol GA treatments were not as effective as the synthetic insecticide in reducing flower and pod damages by the two key pests in 2021 and 2022 cropping season. However, these two treatments performed better than the other remaining bio-insecticides, which were in turn better than untreated control. Similarly, three applications of Powerfist-GA produced appreciably higher increase in yield than all the other bio-insecticides in both years and was statistically lower (523.0 kg/ha), but comparable (695.0 kg/ha) to that produced by Imidacloprid treated cowpea in 2021 (898.0 kg/ha) and 2022 (704.0 kg/ha), respectively. In conclusion, three sprays of Powerfist GA bio-insecticide effectively reduced the population of thrips and pod damage by the legume pod borer and is thus recommended for cowpea yield optimization and environmental quality at the study location.