Harnessing the Potential of Foliar Spray of Nitrogen Sources and Growth Hormones in Alleviating the Waterlogging Stress in Maize

ABSTRACT Increasing waterlogging events due to intense rainfall pose a significant threat to global food security, risking the production of the third most important staple crop, maize by 25%–34%. Therefore, futuristic studies focusing on understanding the stage‐wise response of maize to varying intensities of waterlogging, along with effective mitigation strategies, are essential. In this context, studies were conducted over 2 years (2022–23 and 2023–24), involving three factors: crop growth stages, different waterlogging durations, and mitigation strategies. Among the growth stages, waterlogging at 15 days after emergence (DAE) was found to be the most sensitive, resulting in poor root morphological features, impaired physiological activities, and the highest grain yield reduction (46.01%). In contrast, maize plants exhibited higher tolerance to waterlogging at 25 DAE. Similarly, increasing waterlogging duration from 3 to 15 days consistently reduced maize growth and grain yield. Regarding mitigation strategies, foliar application of urea (2%) improved stomatal conductance by 41.32%, net photosynthetic rate by 36.03%, and dry matter accumulation compared to water‐sprayed plants. Consequently, it increased grain yield by 17.37%, enhancing stress tolerance and yield stability. Notably, urea spray (2%) on plants subjected to 3–5 days of waterlogging at 25 DAE effectively prevented the negative impacts of waterlogging on grain yield by promoting superior growth and yield‐determining traits. Thus, this study demonstrates that foliar application of 2% urea is an effective and practical strategy to minimise waterlogging‐induced yield losses by enhancing stress recovery and tolerance in maize.