Maize–Legume Intercropping and Push–Pull for Management of Fall Armyworm, Stemborers, and Striga in Uganda

Abstract

Core Ideas Recommending complex maize pest management options for small‐scale African farmers. Determining effective and environmentally friendly fall armyworm management for smallholder farmers. Evaluating effects of edible legume and maize intercropping on fall armyworm. Maize (Zea mays L.) production in Africa is constrained by several biotic and abiotic factors. The recent occurrence of fall armyworm (FAW), Spodoptera frugiperda (JE Smith) a new invasive pest in Africa, has escalated the problem. Push–pull technology (PPT), proven to be effective for stemborers (Chilo partellus Swinhoe and Busseola fusca Fuller) and the parasitic weed striga (Striga hermontica Delile) management in Africa has been shown to provide good control of FAW. This study investigated if intercropping maize with edible legumes can also reduce the abundance of FAW. Six treatments including (i) climate‐smart PPT, (ii) conventional PPT, (iii) maize intercropped with bean (Phaseolus vulgaris L.), (iv) maize intercropped with soybean [Glycine max (L.) Merr.], (v) maize intercropped with groundnut [Vigna unguiculata (L.) Walp.] and, (vi) mono‐cropped maize were evaluated on farm in six districts of Uganda in the 2017 short rains season. Data collected included FAW, stemborer, and striga infestation symptoms, and severity of infestation. Climate‐smart PPT performed best in reducing stemborer, FAW, and striga infestation followed by conventional PPT over all the phenological stages of maize. Intercropping of maize with leguminous crops also provided significant reduction of stemborer and FAW compared to mono‐cropped maize, especially in the early growth phases of the maize up to tasseling. However, intercropping of maize with edible legumes was not very effective for striga management as compared to PPT. Hence in addition to PPT, intercropping of maize with edible legumes could also be an alternative FAW management option when integrated with other sustainable management measures.

Fall armyworm ( Spodoptera frugiperda ) management by smallholders.

“…Van Huis [41] showed in Nicaragua that intercropping maize with beans reduced the percentage of maize plants infested by S. frugiperda by 20% to 30%. Hailu et al [42] demonstrated that intercropping common beans or groundnut with maize has reduced FAW oviposition by 30% in maize in Uganda.…”

The Efficacy of Alternative, Environmentally Friendly Plant Protection Measures for Control of Fall Armyworm, Spodoptera Frugiperda, in Maize

“…For instance, cultural techniques such as early planting have been suggested to contribute to successful FAW management [15]. Intercropping maize with legumes (e.g., beans) may also reduce FAW damage, especially when beans are sown earlier than maize [16]. Push-pull approaches have been shown to reduce populations of FAW, in some cases substantially, under African conditions [16,17], and a recent review also mentioned sound fertilization, soil management, and habitat diversification as factors able to reduce FAW incidence [13].…”

Diversity of fall armyworm, Spodoptera frugiperda and their gut bacterial community in Kenya

“…A recent survey in Ethiopia, Kenya and Tanzania indicated that S. frugiperda has established interactions with indigenous parasitoid species (Sisay et al 2018) that could be harnessed for biological control. A study on S. frugiperda host plant interactions in East Africa has also suggested a climate adapted push-pull system (Midega et al 2018) and maize-legume intercropping (Hailu et al, 2018) for management of pests including fall armyworm on maize farms. However, many factors related to S. frugiperda rapid spread, host plant interactions, bio-ecology and insect-microbiome interactions in the African region remain poorly understood.…”