Pearl millet is mainly grown under rainfed conditions and often experiences terminal drought stress due to the early withdrawal of the monsoon. This stress results in significant yield losses. Reducing leaf transpiration during critical growth stages is an important physiological adaptation, as it helps conserve water, maintain plant water status, and enhance the crop’s ability to withstand dehydration stress. This study investigated the effect of foliar application of chitosan nanoemulsion on drought tolerance traits in pearl millet. The nanoemulsion was prepared using a 1% chitosan solution and diluted to a final working concentration of 0.1% for foliar spray, while the control plants received water spray. Drought stress was imposed during the reproductive stage by withholding irrigation under controlled glasshouse conditions. Chitosan‐treated plants exhibited higher chlorophyll content, soluble protein, nitrate reductase activity, proline accumulation, and antioxidant enzyme activities compared to the control. Water use efficiency increased by 32% with chitosan application. Microscopic observations revealed a marked reduction in stomatal aperture width in treated plants, providing direct anatomical evidence of stomatal regulation under drought stress. The results show that foliar application of chitosan nanoemulsion improves drought tolerance in pearl millet by enhancing water‐use efficiency and strengthening antioxidant defense mechanisms.
Natarajan et al. (Thu,) studied this question.