Influence of Heat Stress, Variations in Soil Type, and Soil Amendment on the Growth of Three Drought–Tolerant Maize Varieties

Abstract

Food security in sub–Saharan Africa is threatened by the increasing incidence of heat stress. Therefore, ameliorating heat stress influence in plants is vital for sustainable crop production. A 2 × 3 × 3 × 2 factorial experiment fitted into a completely randomized design with four replications was performed. The factors were heat stress, maize variety, soil amendment, and soil type. The results showed that heat stress exerted a depressive effect on maize growth and yield attributes. It reduced the leaf chlorophyll content, leaf area, plant height, stem diameter, dry biomass yield, and harvest index by 35%, 36%, 41%, 59%, and 78%, respectively. Sandy clay loam soil provided a better maize growth condition than loamy sand soil. Organic manure soil amendment improved maize growth attributes over the mineral fertilizer in the non–heat–stress environment and ameliorated the negative impact of heat stress in the heat–stress environment. The ranking of the attributes identified leaf area, dry biomass yield, stem diameter, and plant height as the most discriminating and representative attributes. These attributes should be considered in maize development projects for heat–stress prone areas. Selection of appropriate maize variety and accompanying soil amendment should be integrated into food security strategy as they influenced maize growth and yield under (non–)heat–stress conditions.