Response of OPV Corn (Zea mays) to Antitranspirants (Chitosan) Under Drought Stress

Chitosan is gaining recognition in crop science as a natural antitranspirant that improves plant water-use efficiency and enhances resilience under drought stress. This study investigated the effects of chitosan derived from golden apple snail shells on the growth, physiological response, and yield performance of glutinous open-pollinated variety (OPV) corn (Zea mays) under drought conditions. Conducted from February 23 to April 29, 2025, in Macatoc, Victoria, Oriental Mindoro, the experiment followed a 3×4 factorial design using a Randomized Complete Block Design, with Factor A being water stress intervals (regular, 15 days, and 25 days) and Factor B being chitosan levels (0, 50, 100, and 150 ml/L). Results showed that the first factor (water stress interval) had a significant effect (p<0.05) on key growth traits such as plant height, number of leaves, leaf area, and fresh and dry biomass, with regular watering (A1) producing superior values compared to 15-day (A2) and 25-day (A3) intervals. However, yield components like corn ear diameter, length, and weight showed comparable results between A1 and A2, suggesting moderate water stress did not drastically affect reproductive traits. The second factor (chitosan level) significantly influenced all parameters, with 100 ml/L (B3) producing the best performance in plant height, leaf area, number of leaves, biomass, corn ear traits, Relative Water Content (RWC), and Excised Leaf Water Retention (ELWR). The 150 ml/L treatment (B4) also improved traits but with diminishing gains or slight physiological suppression. The interaction between water stress intervals and chitosan levels was significant for plant height, number of leaves, leaf area, and RWC, especially at 6 and 8 weeks after planting. Notably, the combination of 100 ml/L chitosan and 15-day water stress interval (A2B3) showed performance comparable to the regularly watered treatment, indicating chitosan’s mitigating role under moderate drought. These findings support the application of chitosan at optimal concentrations as an eco-friendly, biodegradable strategy to enhance maize performance under water-limited conditions, reinforcing its value in climate-smart agriculture.