不同遮光度对冬小麦生长发育和水分利用效率的影响

[目的]探究不同程度遮光对冬小麦生长发育和水分利用效率的影响,分析遮光条件下小麦的生长发育状况及耗水特性,为节水灌溉提供新途径。[方法]通过小区试验,设置不遮光(CK)、20%遮光(L_(20))、40%遮光(L_(40))、60%遮光(L60)、80%遮光(L_(80))共5个处理组,分析冬小麦株高、叶面积、干物质、产量和水分利用效率的变化特征。[结果]遮光处理使冬小麦生育期延长,叶面积增加,但各处理间的株高无明显变化;L_(40),L60,L_(80)处理抑制了冬小麦茎、穗干物质的积累;遮光使得光合产物在茎、叶、穗各器官中的分配比例发生变化,但L_(20)处理对冬小麦茎、叶、穗干物质的积累和分配无明显影响;遮光使得土面蒸发量和冬小麦的总耗水量均明显降低,且遮光度越大,降低幅度越大;与CK相比,L_(20)处理的产量下降了4.23%,水分利用效率则提高了10.11%,其他处理的产量和水分利用效率均有所下降。[结论]L_(20)处理对产量无明显影响,但有效提高了水分利用效率,起到了明显的节水作用。

Effects of Different Shading Treatments on Growth and Water Use Efficiency of Winter Wheat

[Objective] To explore the influence of different shading on the growth and development of winter wheat and water utilization efficiency, and to analyze the growth and water consumption characteristics of wheat under the condition of shading, so as to provide a new way for water-saving irrigation.[Methods] The characteristics of leaf area, dry matter, yield and water use efficiency of winter wheat plants were studied through cell experiments, which sets five treatment groups:non-shading(CK), 20% shading(L₂₀), 40% shading(L₄₀), 60% shading(L₆₀) and 80% shading(L₈₀).[Results] The growth period of winter wheat was prolonged and the leaf area was increased through shading treatment, but there was no obvious change in plant height in each treatment; The shading of L₄₀, L₆₀ and L₈₀ inhibited the accumulation of stems and ear dry matter in winter wheat, and had the function of inhibiting leaf dry matter first and then promoting it; The allocation proportion of dry matter in stems, leaves and ear organs of winter wheat was changed by shading, but there was no significant impacts on the accumulation and distribution of winter wheat stem, leaf, and dry matter in L₂₀ shading; Both soil evaporation and total water consumption of winter wheat were significantly reduced in shading, and the larger the shading degree, the greater the decrease; Compared with CK, the yield of L₂₀ treatment was decreased by 4.23%, the water use efficiency was increased by 10.11%, and the yield and water use efficiency of other shadings was decreased.[Conclusion] It can be seen that the water-use efficiency is effectively improved and the water saving effect is obvious without obvious effect on yield in L₂₀ shading.