【摘要】 不同时期和不同量的供水对春小麦不同叶位叶片的光合作用特性及水分利用效率有影响。表现在供水适量对高叶位叶片光合作用午休有迟滞和不同程度的减轻；群体冠层中湿度和光照分布随叶位的升高而增高；拔节期供水能降低蒸腾作用，并明显提高高叶位叶片的净光合和水分利用效率。更多还原

【Abstract】 In this study investigated were the effects of intermittent irrigation on photosynthetic characteristicsand water use efficiency(WUE)of leaves at different nedes of spring wheat growing in semi一arid cond-itions.The resuIts indicated that irrigation of an adequate volume of water could postpone and red uce themidday depression of leaves at higher nodes.The humidity and solar radiation interception in the canopiesof wheat population increased with the height of leaves ’node from the ground level.Irrigation in thephase of fast intercalary growth of wheat could decrease transpiration and lead to a notable increase in therate of photosynthesis and the efficiency of water use for the leaves at higher nodes.更多还原