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Maize (Zea maysL.), an important source of calories and nutrients in sub‐Saharan Africa, is threatened by northern corn leaf blight (NCLB) caused by Exserohilum turcicum. This study examined combining ability and heterotic patterns of early‐maturing maize inbreds, gene action conditioning NCLB resistance, and performance of derived hybrids across environments and identified testers. Fifteen each of white and yellow inbreds were intercrossed using North Carolina Design II to obtain 75 hybrids per endosperm color. Hybrids plus six checks were inoculated with a virulent isolate of E. turcicum4 wk after planting in six inoculated and three non‐inoculated environments in Nigeria in 2018 and 2019. Inbreds were assigned to heterotic groups using general combining ability (GCA) of multiple traits method. Specific combining ability (SCA), GCA, and genotype × environment (G × E) interactions were significant for grain yield (GYLD), disease severity, and other traits. Northern corn leaf blight caused 46% GYLD reduction. The effects of GCA were preponderant over SCA for GYLD and NCLB severity across environments, indicating that hybridization and recurrent selection would enhance genetic gains and hybrid performance. White and yellow inbreds were placed in two and three heterotic groups, respectively. High‐yielding NCLB‐resistant testers identified could be used to classify other inbreds yet to be field‐tested into heterotic groups. Genotypes TZEI 32 × TZEI 5 and TZEI 124 × TZEI 134 were identified as single‐cross testers. Genotypes TZEI 32 × TZEI 5 and TZEI 5 × TZEI 75 (white) and TZEI 124 × TZEI 134 and TZEI 124 × TZEI 11 (yellow) were identified for on‐farm testing and possible commercialization. Gene action for grain yield and turcicum resistance was predominantly additive in early‐maturing (EM) inbreds.Three heterotic groups identified for planned hybrid crosses involving EM inbreds.Inbred and single‐cross testers identified for grouping and testing for turcicum resistance.Identified testers should be used to classify EM inbreds that are yet to be field‐tested.Ten high‐yielding and stable hybrids with turcicum resistance identified for commercialization.

Maize (Zea maysL.) is a food security crop in sub‐Saharan Africa (SSA). Incidence of northern corn leaf blight (NCLB), caused by Exserohilum turcicum, in lowlands of SSA during the past decade has caused 30–70% reduction in maize yield. This study (a) examined the combining abilities of extra‐early maize (EEM) inbreds and classified them into heterotic groups; (b) elucidated gene action controlling resistance to NCLB; (c) assessed grain yield (GYLD) and yield stability of EEM hybrids under NCLB infection; and (d) identified testers. One hundred and fifty EEM hybrids, obtained by crossing 15 inbreds each of white‐ and yellow‐endosperm maize using the North Carolina Design II, plus six checks, were evaluated in nine environments, six of which were inoculated with an isolate of E. turcicumand three of which were non‐inoculated in 2018 and 2019. The white and yellow inbreds were placed in three heterotic groups using the heterotic grouping based on general combining ability (GCA) of multiple traits and stability of GYLD using the genotype plus genotype × environment (GGE) biplot analysis. The GCA, specific combining ability (SCA) and genotype × environment (G×E) interactions were significant for GYLD, disease severity, and other measured traits. The GCA effects were more important than the SCA effects for GYLD and NCLB severity scores across environments, implying that recurrent selection could facilitate improvement for GYLD and NCLB resistance. Three inbred testers and four single‐cross testers were identified for developing high‐yielding NCLB‐resistant hybrids. Four white and five yellow single‐cross hybrids were identified for on‐farm testing and possible commercialization.

Maize, the critical staple food for billions of people, was domesticated in Mexico about 9,000 YBP. Today, a great array of maize landraces (MLRs) across rural Mexico is harbored in a living library that has been passed among generations since before the establishment of the modern state. MLRs have been selected over hundreds of generations by ethnic groups for adaptation to diverse environmental settings. The genetic diversity of MLRs in Mexico is an outstanding resource for development of maize cultivars with beneficial traits. Maize is frequently contaminated with aflatoxins by Aspergillus flavus,and resistance to accumulation of these potent carcinogens has been sought for over three decades. However, MLRs from Mexico have not been evaluated as potential sources of resistance. Variation in susceptibility to both A. flavusreproduction and aflatoxin contamination was evaluated on viable maize kernels in laboratory experiments that included 74 MLR accessions collected from 2006 to 2008 in the central west and northwest regions of Mexico. Resistant and susceptible MLR accessions were detected in both regions. The most resistant accessions accumulated over 99% less aflatoxin B1than did the commercial hybrid control Pioneer P33B50. Accessions supporting lower aflatoxin accumulation also supported reduced A. flavussporulation. Sporulation on the MLRs was positively correlated with aflatoxin accumulation (R= 0.5336, P< 0.0001), suggesting that resistance to fungal reproduction is associated with MLR aflatoxin resistance. Results of the current study indicate that MLRs from Mexico are potentially important sources of aflatoxin resistance that may contribute to the breeding of commercially acceptable and safe maize hybrids and/or open pollinated cultivars for human and animal consumption.

In 2015, all United Nations Member States adopted the 2030 Agenda for Sustainable Development to achieve peace and prosperity for all people in the planet. Meeting that ambitious agenda depends on fulfilling all objectives of 17 Sustainable Development Goals (SDGs). Multiple approaches by diverse actors, many of them interconnected, will allow achieving each SDG. However, with compromised food security and food safety, many SDGs will not be realized. In sub-Saharan Africa (SSA), maize and groundnut are two staple crops frequently contaminated with aflatoxins, which threaten food security and food safety. Aflatoxins are extremely dangerous compounds produced primarily by the fungus Aspergillus flavus. Even at minute concentrations, aflatoxins negatively influence health, income, and trade sectors. Farmers, traders, industries, and consumers become affected. However, practical solutions exist. Non-aflatoxin producing isolates (referred to as atoxigenic) of A. flavuscan decrease crop aflatoxin content when used in biocontrol formulations to competitively displace aflatoxin producers during crop development. Typically, treated crops contain 80%–100% less aflatoxin than non-treated crops. The technology was developed by USDA-ARS for use in the US and has been adapted and improved for use in SSA where several products under the tradename Aflasafe are available. There are biocontrol products registered for use in 10 SSA countries and more are being developed. On the other hand, although highly effective, biocontrol is not a panacea. Less aflatoxin occurs across value chains when biocontrol is combined with other practices. In this review, we discuss how i) aflatoxin biocontrol products are developed, manufactured, licensed, and commercialized, ii) aflatoxin management strategies are designed, and iii) integrated aflatoxin management is or will soon be contributing to achieve, in several countries, many targets of most SDGs. We present integrated aflatoxin management as a model intervention contributing to tackle several challenges impeding prosperity and peace in SSA.