Sustainable control of pests and Striga weed through intensified push-pull technology and frass-based soil amendments

Crop productivity under African smallholder farming systems is faced by numerous challenges, including insect pests, weeds, low soil fertility, and climate change. Sustainable intensification, such as push-pull (PP) technology and vegetable-integrated push-pull (VIPP) technology, coupled with soil organic amendments such as black soldier fly frass fertilizer (BSFFF), can address these agricultural constraints. We investigated the individual and synergistic effects of cropping systems comprising two crops [maize (DK777 variety) and cowpea (KVU27 variety)] and agroecological strategies (PP, VIPP and BSFFF) on the management of pests and Striga weeds and crop productivity in three different geographical areas. Diversified cropping systems (PP and VIPP) resulted in a 54% and 33% reduction of foliar damage by fall armyworm and stem borer, respectively, translating to significantly lower ear damage by these pests. Diversified cropping systems also significantly reduced Striga weed infestation on maize plants by at least 45%. The populations of aphids, thrips, pod-sucking bugs and leafminers on cowpeas significantly reduced by about 69%, 63%, 44% and 25%, respectively, in diversified cropping systems. Predatory beetles showed density-dependent responses, with the highest numbers observed in cowpea monocrops compared to cowpea in the diversified cropping systems. Diversified cropping systems and BSFFF improved crop yield, translating to economic benefits of at least 51% and 23%, respectively. Our findings demonstrate that diversified cropping systems can reduce pest pressure, Striga weed infestation and reliance on chemical inputs while maintaining crop productivity. Therefore, integrating diversified cropping systems with frass-based soil amendments provides a strong pathway for improving the productivity and economic benefits of cereal crops (maize) and vegetables (cowpea) in smallholder farming systems.