Moringa leaf and sorghum water extracts and salicylic acid to alleviate impacts of heat stress in wheat

Late planted wheat crop is often subjected to high temperature stress during grain filling which leads to a decline in overall performance of the crop. A field study was conducted to mitigate the impact of heat stress on wheat cultivars (Sehar-06 and Fsd-08) by exogenous application of moringa leaf extract (MLE) along with sorghum water extract (SWE) and salicylic acid (SA). The plants were covered with transparent plastic sheet tunnel to impose heat stress on wheat. To alleviate the damaging effects of heat stress on wheat, different growth promoting substances (3% MLE, 0.075% SWE, 0.01% SA) including distilled water were applied with an interval of one month. The results revealed that SWE and MLE maximally enhanced yield contributing factors i.e. spike length, number of grains per spike and 1000-grain weight. On the other hand, maximum number of productive tillers and biological yield were recorded with SA and MLE. Maximum protein and CAT were recorded in Sehar-06 due to SA and MLE treatments, respectively while Fsd-08 showed higher activity of POD with MLE spray. SA maximally enhanced free proline in both wheat cultivars while total soluble sugars by MLE. In conclusion, exogenous application of natural and synthetic growth promoting substances could be useful to enhance heat tolerance of wheat plants by improving growth and development, accumulation of metabolites, relative water contents and minimizing oxidative damage. (C) 2019 SAAB. Published by Elsevier B.V. All rights reserved.