Effect of Water Stress on Dry-matter Partition and Yield Constitution of Winter Wheat
水分胁迫对冬小麦物质分配及产量构成的影响

Dry-matter accumulation,partition and yield of winter wheat by different irrigation or water stress in different development stages was analyzed.The proportion of stem was low and the proportion of spike was high under the fitting water condition,there were24%of stem and56%of spike.But on the condition of water stress,the proportion of stem became higher and the proportion of spike was lower.On condition of water shortage,the proportions of stem and spike were36%and43%respectively,and on the redundant water condition,the proportions were37%and48%.The contribution from stem to yield was0.308g/stem under the fitting wa-ter condition;on the condition of water shortage the contribution from sheaths to yield was high-est in treatments,was0.18g/stem.The relationship between yield and evapotranspiation indicat-ed that the highest theoretical yield was6240kg/hm 2 in Yucheng under present fertilizer and management level.The evapotranspiration at highest yield was473mm;and the evapotranspira-tion was403mm when water use efficiency was highest.Groundwater was an important water resource in this area.Amount of water supplied by groundwater to wheat from jointing to maturi-ty stages was22%of total water consumption of winter wheat.