Effects of temporary water stress before anthesis on growth, development and grain yield of spring wheat

Abstract

Soil water availability can limit grain yields of spring wheat in humid climates. The objective of this study was to quantify the effect of temporary water shortage at three stages during the development, i.e. stem elongation to flag leaf stage (WS 1), flag leaf stage to ear emergence (WS2) and ear emergence to anthesis (WS3) on the growth, development and grain yield of spring wheat with special emphasis on the interaction between cultivars and nitrogen treatments. A pot experiment with controlled water supply and rain shelters was conducted in 1984 and 1985 in Kiel, NW Germany.The largest relative effect of a temporary water stress on crop development occurred after the first treatment period, EC 31 to 39 (Zadoks scale). Fresh weight, dry weight and the number of tillers per plant as well as the apex length of the second category tillers were reduced compared with the untreated control. After rewatering, the differences diminished and eventually plants which were subjected to the WS 1 treatment produced more tillers than the control.The largest yield decrease, associated with a reduced number of kernels per ear, was observed after the WS3 treatment. The two other treatments caused a yield increase due to a compensatory increase in the number of kernels per ear in the second category tillers. Additional nitrogen partly compensated for the effect of a temporary water shortage at WS1 or WS2 by increasing the single ear yield of the second category shoots.