Drought Stress Mitigation through Antioxidant Defence Response in Sugar Beet Under Various Foliar Applications

Abstract

The rapid increase in climate change is leading to serious changes in global weather patterns, influencing overall plant responses, where heat waves, cyclones, floods, and flash or long-term droughts become more frequent. Drought stress intensified atmospheric moisture demand which, accelerated by rising temperatures, led to serious soil water depletion. This climate- driven cycle remains a major environmental concern. A two-year study was conducted during “winter-summer” season, evaluating the effect of three levels of irrigation and seven foliar treatments on tropical sugar beet under Odisha condition. A significant impact of water scarcity was observed in the S2 stressed plants, where MDA increased from 5.05 to 13.8 nmol. g-1. Confronted with the harmful effect of drought, sugar beet induces its defence mechanisms, when the stress intensity increased from moderate(7days) to severe(14days) for prolonged period. As a result, it induced increase in antioxidant enzyme activities in the leaves like CAT, SOD, APX, and POD were recorded 1.97, 205.29, 2.15, and 1.51 u.g-1.min-1 respectively, under 14 days of severe stress cycles after 4th spray. Stress impact was also reflected in phenolics accumulation as well as proline. Foliar application of various treatments showed a significant ability to protect cell metabolism through up-regulating defence pathways against oxidative stress. Among all effective foliar treatments, SA, N-Si, Chitosan and JA exhibited as promising in alleviating prolonged drought stress in sugar beet.