Summary:

Efficient water management is critical in modern agriculture, particularly in the face of increasing water scarcity and climate variability. Maize, a major cereal crop worldwide, is highly sensitive to water availability, making irrigation management a key factor in sustaining both yield and grain quality. This study was conducted to investigate the impact of deficit irrigation, including partial root-zone drying (PRD) techniques, on the grain quality parameters of maize. The experiment evaluated the effects of different irrigation levels 100% (full irrigation), 75%, 50% (with and without PRD), and 25% on key biochemical attributes of maize grain. Results revealed a significant influence of irrigation level on most grain quality parameters. ADF content increased progressively with reduced water application, peaking at 3.90% under 25% irrigation, while the lowest value (3.43%) was recorded under full irrigation. Conversely, NDF and hemicellulose contents were highest under full irrigation (19.13% and 15.70%, respectively) and decreased under severe water stress. Starch content also declined with increasing water deficit, with the maximum value under full irrigation and the lowest (63.33%) under 25% irrigation. Protein content was highest in the fully irrigated treatment, though differences among treatments were not statistically significant. Oil content showed a similar trend, with maximum values (2.80%) under full irrigation and a marked reduction under 25% irrigation. Ash content was unaffected by irrigation treatments. In conclusion, deficit irrigation, particularly severe water stress adversely affects several nutritional components of maize grain, especially fiber, starch, and oil content. However, moderate water-saving strategies like 50% irrigation with PRD may help maintain quality with reduced water input. These findings suggest that precision irrigation strategies can be optimized to conserve water without substantially compromising grain quality.