Comparable Yield Performance of Drought-Tolerant and Conventional Maize Hybrids Under Contrasting Water Management

Climate change has intensified plant water stress due to rising temperatures and irregular rainfall, which often fails to meet crop water requirements. Consequently, irrigation has become essential for optimizing the yield of drought-sensitive crops such as maize. Drought-tolerant (DT) maize hybrids represent a promising strategy to increase resilience under water-limited conditions. This study evaluated the qualitative, morpho-physiological traits, and yield of six maize hybrids, comprising one drought-tolerant (DT) and one conventional (Conv) hybrid for each of three maturity classes (FAO 300, 400, and 500), in Veneto, northeastern Italy. Hybrids were grown under rainfed and fully irrigated conditions. Irrigated plots received 51.7% more water than the rainfed ones. Irrigation increased plant height by 20.4%. At full development, irrigation raised the plant dry weight by 19.7% and ear weight by 24.7%, relative to rainfed management. At harvest time, the grain yield was 48.7% higher under irrigation than under rainfed conditions. No significant effect of drought tolerance was observed on grain yield. Rainfed maize produced grain with higher protein content. Grain from the DT hybrids had lower protein but higher oil content than grain from the Conv hybrids. Therefore, in environments characterized by high temperatures and irregular but not extremely limiting rainfall, management strategies that secure adequate water supply during the reproductive stages remain more effective for sustaining maize productivity than the sole adoption of DT hybrids. These findings should be confirmed through multi-year, multi-site experiments covering a wider range of water availability conditions.