Heat Stress Effect on the Grain Yield of Three Drought-Tolerant Maize Varieties under Varying Growth Conditions

Abstract

A rise in global temperature will reduce maize yield, particularly in Africa, where maize is a staple food. Therefore, improving maize yield under heat stress will promote food security in the region. The objective of this study was to assess the influence of heat stress on the grain yield of drought-tolerant maize varieties under varied growth conditions. The experimental design used was a 2 × 3 × 3 × 2 factorial fitted into a completely randomized design with four replications. The factors were heat stress, maize variety, soil amendment, and soil type. The results showed a better yield from sandy clay loam over loamy sand soil. Varieties WE5323 and ZM1523 amended with poultry manure gave the best yield under the non-heat and heat-stressed environments, respectively. Heat stress reduced the cob weight, grain weight, grain number, and stover dry weight by 64, 73, 69, and 23%, respectively. Grain number, grain weight, and cob weight were the most informative yield attributes in this study and should be considered in a maize selection program. The ranking for the maize varieties was WE5323 > ZM1523 > WE3128. Drought-tolerant maize varieties can be useful in heat stress mitigation. This information is useful for the simulation of maize yields for heat stress-prone areas in Sub-Saharan Africa.

The Influence of Parental Heat-Stress Priming on Drought-Tolerant Maize Progenies’ Field Performance

“…Since grain yield determines the economic value of maize varieties, the treatment interactions' progenies were clustered in this study based on yield-related attributes. The findings in this study that GWt and CWt were the most informative attributes agreed with previous reports on maize studies [3,33,34].…”

“…This finding highlights the importance of including heat stress tolerance in maize cultivar development [20]. It has been demonstrated that the response of maize plants to a single stressor differs from the synergistic effect of multiple stressors [3,4]. However, more research is needed to determine how these stressors affect maize progeny.…”

“…The treatments evaluated in this field study were developed from a 2 × 3 × 3 factorial in a completely randomised greenhouse experiment [3,21]. The greenhouse experiment is described briefly.…”

“…Heat waves are expected to become more severe and frequent, posing a risk to global food security [17]. Heat stress has a negative effect on maize plants [3,21]. As plants are exposed to constant temperature fluctuations in the field, improving their thermotolerance is critical for their survival [7].…”

“…Plants, as sedentary organisms, respond to stress by modifying their physiological and genomic architecture [1]. These adjustments frequently result in decreased resource utilisation efficiency, which can result in yield losses ranging from minor to severe losses, or, in the worst-case scenario, plant death [2][3][4].…”