Flowering and pollination appear to be the most sensitive periods. Several studies have been conducted with spring wheat and winter wheat to evaluate the effect of limited irrigations on crop quality and production. Stress was most critical during and after heading. This response is similar to that for barley. There is little or no measurable benefit from irrigating spring grains before the boot stage, unless moisture stress is evident.
Stress is likely to occur when the plants appear wilted and the leaves curl.
The period between grain filling and maturity is critical. Yield is reduced the most when stress starts during soft dough or during or following heading. Stress during the maturing process results in about a 10 percent lower yield. Moderate stress during the early vegetative period has essentially no effect on yield. Drought stress on winter wheat production during early spring regrowth results in heading approximately seven to 10 days prematurely.