EXOGENOUS APPLICATION OF GROWTH PROMOTERS CAN IMPROVE THE CHICKPEA PRODUCTIVITY UNDER TERMINAL HEAT STRESS CONDITIONS BY MODULATING THE ANTIOXIDANT ENZYME SYSTEM

Heat stress causes irrecoverable damage to plant growth, thus adversely affecting the crop productivity. This study was planned to minimize the heat stress induced-losses to chickpea plants with the exogenous application of growth promoters i.e. moringa leaf extract (MLE), jasmonic acid 100 mu M and proline 10uM including distilled water as a control. Two chickpea cultivars (Thal-2006 and Noor-2013) cultivated under optimum sowing time (25th October) and late sowing (25th November) to expose heat stress at the reproductive phase. Results indicated that heat stress severely reduced the chickpea growth and productivity. It was observed that exogenously applied MLE and proline improved productivity even under heat stress conditions as compared to control. However, exogenous application of MLE had a greater influence on the studied parameters than proline, although the insignificant differences were documented in some of the traits. Exogenous application of MLE produced significantly taller plants with improved 100-grains weight, economic yield, biological yield and harvest index. However, foliar spray of proline produced significantly higher enzymatic antioxidants activities than MLE that modulated the adverse impacts of heat stress on yield contributing attributes. Our results suggest that exogenous application of plant growth promoters particularly moringa leaf extract and proline modulated the heat stress induced losses to chickpea plants by improving their antioxidant defense mechanism and enhanced the productivity.