Drip Irrigation System Aids in Mitigating Effects of High Temperature Stress in Wheat.

Wheat, a globally important cereal crop, is affected by high temperatures in most growing regions of the world. Global predictions on increasing temperatures are a threat to maintaining future wheat productivity. While development of heat tolerant wheat varieties is the most important component in sustaining wheat production, management of resources such as irrigation could also be a key to mitigating heat stress effects and maintaining grain yields. Transpiration, one of the key processes in plants enables evaporative cooling under high temperatures and maintains functioning of the physiological and metabolic processes in plants. Under well-watered conditions, plants consume a considerable amount of water than required for optimal yield and majority is lost via transpiration. Use of drip system allows the regulation of the amount and time of application of water and is considered to be an efficient way to irrigate crops. A study was conducted with spring bread and durum wheat varieties for four years (2013-2016) in Ciudad Obregon, Sonora, Mexico to evaluate the efficacy of the drip irrigation system in mitigating heat effects. Trial was planted in November under two management systems: flat planting with drip irrigation (DI) and flat planting with flood irrigation (FI) in each year. FI followed the regular irrigation and nutrient management system, while drip system was used to regulate the quantity and time of application of water and nutrients during the crop cycle in DI. Mean temperatures during crop seasons in Ciudad Obregon varied year to year with 2015 being the hottest. It was observed mean grain yields in DI were maintained across years, while significant effect of temperature on GY was observed in FI. Significant grain yield losses were reported in 2015 from the farmer’s field as well. Results demonstrate that application of water using drip system and regulating the timing of application can help in reducing high temperature stress effects on grain yield.