Maize response to combined heat and water stresses under varying growth conditions

Abstract Identificationof agronomic practices that can ameliorate the negative effect of combined heat and water stress on maize plants is vital in food security strategy. The objective of this study was to evaluate the effect of heat and water stress on the growth of maize ( Zea mays L.) under variable growth conditions. A repeated greenhouse factorial experiment laid out in a completely randomized design with four replications was performed. The factors were maize variety, water stress, soil amendment, and soil type. The results showed a depressive effect of water stress on the maize leaf area, chlorophyll content, stem diameter, dry biomass yield, and harvest index. These attributes decreased as the severity of the water stress increased with harvest index dipping by 30.3 and 92.9% in moderate water stress (MS) and terminal water‐stress (TS) plants, respectively. Sandy clay loam soil gave higher maize growth and yield attributes than loamy sand soil. The varied growth conditions imposed by the different water stresses, soil types, and soil amendments elicited different responses from the three maize varieties. Mean stability analyses/ranking identified ZM1523 and WE5323 as the top‐performing varieties under poultry manure amendment for both non‐stress and MS conditions, whereas under TS their performance improved in combined poultry manure/mineral fertilizer and mineral fertilizer treatments. Similarly, WE3128 gave its best performance under mineral fertilizer amendment for non‐stress, MS, and TS conditions. Therefore, under combined heat and water stress conditions, the interaction of maize variety, soil type, and soil amendment should be considered to guarantee a high maize yield.