Production and Photosynthetic Indicators of Maize Hybrids (Zea mays L.) Under Drought Conditions in a Semi-Arid Region

Drought is one of the main constraints affecting crop production in the current climate change scenario. The desert area of Chihuahua in Mexico has limited water availability and is therefore susceptible to drought. Plant photosynthetic performance is the main determining factor of crop productivity, especially under stress conditions. The present study aimed to conduct a comparative analysis of three maize hybrids (P1898, P1445, and P1382) grown under drought stress, focusing on yield, physiological aspects, photosynthetic efficiency, and stomatal activity. A field experiment with these hybrids was carried out in the municipality of Cuauhtémoc, Chihuahua, Mexico, which is characterized by a low precipitation regime. The results indicated that the P1898 hybrid achieved the highest yield and was the best adapted to drought conditions. The analysis of photosynthesis parameters suggests favorable adaptations in both the P1898 and P1382 hybrids such as excess energy dissipation. Additionally, the P1898 hybrid exhibited a greater stomatal area, potentially enhancing CO₂ uptake and heat dissipation via transpiration. The P1382 hybrid demonstrated greater efficiency in photosynthetic energy use and improved water use efficiency (WUE), likely due to its stomatal adaptations. These findings suggest that the P1898 hybrid is the most suitable maize cultivar for cultivation in regions prone to drought and high temperatures, owing to its superior yield and photosynthetic adaptations.