The availability of extra-early maturing varieties has facilitated the expansion of maize production into the savannahs of West and Central Africa. However, maize production and productivity in the region is greatly constrained by low soil nitrogen, drought, and severe infestation by Striga weed. Natural resistance of the host plant to Striga has been considered the most economically feasible and sustainable approach to combat the infestation.
Research was initiated to determine the yield performance and stability of selected extra-early hybrids under drought conditions, artificial Striga infestation, and optimal growing environments. One hundred and twenty extra-early hybrids and an open-pollinated variety were assessed. The productive single-cross hybrids for commercial production under Striga infestation and managed drought stress were identified separately for each stress factor using a standardised selection index.
Genomic study for all measured traits indicated that there was a large variation among the genotypes to allow good progress from selection for improvements for Striga resistance, tolerance to drought that occurs at the flowering including grain-filling periods, and improved grain yield across the test environments. Results are encouraging: the hybrids identified are not only drought escaping but also carry genes that are tolerant to drought at flowering and grain-filling periods as well as genes for Striga resistance.
This is the first report on extra-early maize hybrids with combined resistance to Striga and tolerance genes that can withstand drought stress that occur during the flowering and grain-filling periods. The adoption and commercialisation of the Striga resistant/tolerant and drought tolerant extra-early hybrids should contribute significantly to food security goals and improved incomes of farmers.
The potential vehicles for the dissemination of output from this research work are the agents of national agricultural extension services and non-governmental organisations. Strategies being adopted for promotion of the extra-early hybrids include on-farm trials, farmers’ field days, farmers’ open days, and demonstration plots.