Maize-groundnut intercropping to manage fall armyworm and improved crop productivity in smallholder farming systems

Abstract

Fall armyworm (Spodoptera frugiperda) could cause significant losses in maize production in sub-Saharan Africa, thereby threatening the livelihoods of smallholder farmers. Farming systems such as maize-legume intercropping could reduce fall armyworm (FAW) infestations. However, the impact of maize-groundnut intercropping on fall armyworm infestation and its severity is unknown. We, therefore, assessed the impact of intercropping maize with groundnut planted at different times on fall armyworm infestation while exploring the benefits of groundnut to soil fertility improvement. The study was conducted during the minor 2018 and major cropping season in 2018 and 2019, respectively. Maize-groundnut intercropped treated soils increased the concentrations of Nitrate-N, ammonium, and microbial biomass carbon by 31%, 42%, and 45% respectively, compared with non-groundnut treated soils (control). The treatments had no significant effect on FAW infestation and severity. The number of infected maize plants in Ejura was 68% more than in Fumesua and 88% higher in the minor season than in the major season, irrespective of location. The results also indicated that the severity of FAW infestation determined 30% of the maize grain yield. Major seasons and locations interactively influenced maize grain yield, with the major rainy seasons recording 43% more grain yield than the minor seasons. The study provides further understanding of the mechanisms involved in controlling FAW infestation under maize-groundnut intercropping.