Efficacy of selected biopesticides on key pests of chilli pepper for increased productivity in Ghana

Abstract

Chilli pepper is an important food and cash crop in Ghana. Unfortunately, production and marketing are constrained by many insect pests. In this study, the efficacy of five different biopesticides: Neemazal® (Azadirachtin 0.3% w/w EC), Agro blaster® (Pyrethrin I and II 1% w/w), Bypel 1® (Pieris rapae 10000PIB/mg + Bacillus thuringiensis 16000 IU/mg), Cryptogran® (Cryptophlebia leucotreta Granulovirus ≥ 5.1010 OBs/ml) and Attack® (Emamectin benzoate 1.9% w/w EC) were assessed against the major insect pests of chilli pepper. These pests included the false codling moth (FCM), thrips, whiteflies and fruit flies. The study was conducted during the minor and major cropping seasons of 2019 and 2020, respectively, using RCBD plot design in two locations (Legon and Begoro) in southern Ghana. All five tested biopesticides reduced the infestation of the target insect pests. Neemazal® and Attack® were more efficacious than the other three biopesticides in controlling FCM. For fruit flies, the infestation in Neemazal® and Attack® treated plots varied between 0.69 ± 0.60 to 12.84 ± 0.91% and 1.40 ± 0.69 to 9.72 ± 1.27%, respectively against 3.82 ± 0.67 to 21.87 ± 2.14% in control plots. Neemazal®, Bypel 1® and Attack® significantly reduced thrips population compared to other biopesticides. Apart from Neemazal® and Attack®, Agro blaster® also reduced whiteflies population compared to control plots. The highest yields were recorded in Neemazal® (3.17 ± 0.33 to 4.35 ± 0.22 t/ha) and Attack® (3.05 ± 0.21 to 4.55 ± 0.25 t/ha) treated plots against 2.12 ± 0.31 to 3.06 ± 0.37 t/ha in the control. Therefore, these two biopesticides are promising and could be used as part of integrated pest management (IPM) against chilli pepper insect pests in Ghana.