Potential of foliar applied thiourea in improving salt and high temperature tolerance of bread wheat (Triticum aestivum)

Salinity and high temperature are amongst the highly damaging factors for crop production. The exogenous application of thiourea, due to its distinct properties, can potentially reduce these adverse effects. In this research, we investigated the possible role of foliar spray of thiourea in improving the salinity tolerance threshold (EC_e) and high temperature tolerance of five wheat varieties at seedling, pre-anthesis and grain filling stages of growth. Data were recorded for changes in length and dry weight of shoot and root and leaf area at seedling and pre-anthesis stages, while yield and yield components were recorded at maturity. Results revealed great varietal differences in the salinity and high temperature tolerance at all growth stages. Foliar applied thiourea improved EC_e (6-11%) and high temperature tolerance (4-10%) in these varieties at different stages. Correlations of growth and yield attributes substantiated the effectiveness of foliar spray of thiourea in promoting root growth at seedling and pre-anthesis stages, and grain filling and harvest index at maturity. Among the varieties, thiourea was more effective in enhancing high temperature tolerance of the most high temperature sensitive (S-24) and EC_e of most salt sensitive (MH-97) varieties. In crux, foliar spray with thiourea has a great potential to mitigate the adverse effects of salinity and high temperature and may be recommended for field use in the areas, where moderate salinity or high temperature limit wheat production.