The effects of different deficit irrigation strategies on yield, quality, and water-use efficiencies of wheat under semi-arid conditions

• The water deficits applied in milk stage had slight impacts on yield levels.
• The most sensitive stage of winter wheat was water stress heading and stem elongation.
• The highest protein ratios was obtained water deficits applied in milk stage.
• The highest WUE values were observed with water deficits applied in stem elongation and milk stage.

Central Anatolia is known as the wheat silo of Turkey since the region has the greatest production of wheat in the country. However, the region’s insufficient water resources force producers to use deficit irrigation. The present study was conducted to create deficit irrigation strategies for wheat. Twenty two experimental treatments, including full irrigation and dry treatment, were created based on the different growth stages of wheat (stem elongation, heading, milk stage) and water-deficit levels (0, 35, 65 and 100%). The results revealed different effects of water-deficits on wheat yield, quality, and water-use efficiencies based on the plant-growth stages in which the water deficits are applied. The water deficits applied in the stem elongation and heading stages significantly decreased the wheat yields. On the other hand, a 35% deficit applied only in the stem elongation stage yielded the highest thousand-kernel weight and protein ratio. The seasonal water-consumptive use of experimental treatments varied between 206 and 571 mm; the grain yields varied between 288 and 682 kg da−1; the thousand kernel-weights varied between 33.9 and 52.2 g; the total water-use efficiencies varied between 1.02 and 1.30 kg m−3 and irrigation water-use efficiencies varied between 0.51 and 1.17 kg m−3.