遮光条件下氮肥用量对棉铃生长发育及产量的影响

Effect of Nitrogen Levels on the Growth and Yield of Cotton Bolls under Shading Conditions

人工模拟果棉间作遮光条件下采用裂区试验方法,研究不同光照、施氮水平对棉铃生长发育及产量的影响。结果表明,光照和氮肥共同影响着棉铃生长发育和产量的高低,且光照比氮肥的影响更大;遮光使棉铃体积减小、棉铃干物质积累下降、发育推迟;遮光施氮量为0kg/hm2(N0)、320kg/hm2(N1)、480kg/hm2(N2)处理棉铃体积分别比对照(光照处理)减少2.1%、5.6%、3.7%,铃壳、棉籽、纤维干物质最大积累量分别减少11.8%、8.1%、5.4%,适当增加施氮量会减少其降低程度;遮光条件下不同施肥处理的棉花平均产量比自然光照减少56.9%,中等施氮处理(N1)能获得相对最高皮棉产量(2 931.28kg/hm2),其分别比未施肥处理N0和高施肥处理N2增产63.97%和17.94%。因此,在新疆果棉间作模式下,通过合理增施氮肥可以在一定程度上减轻因遮光导致的产量下降。

In order to study the effects of different light and nitrogen levels on growth and yield of cotton bolls,a split-plot-design experiment was conducted under shading conditions to simulate fruit-cotton intercropping.The results showed that both light and nitrogen had effects on the growth and yield of cotton bolls,but effect of light on cotton bolls was greater than fertilizer.Shading decreased boll volume,dry matter accumulation and delayed it＇s growth.Compared with corresponding nitrogen treatments under natural light condition,the boll volume in the treatments of N0,N1,N2 under shading condition were decreased by 2.1%,5.6%,and 3.7%,and reduced by 11.8%,8.1%,5.4% on boll housing,cottonseed,maximum dry matter accumulation of fiber,respectively,which indicated that nitrogen fertilization could alleviate the effect of shading on cotton.The average yield of cotton in different fertilizer treatments under shading conditions decreased by 56.9%than under natural light condition,but the moderate nitrogen application（treatment N1）had the highest lint yield,2 931.28kg/hm2,under all shading conditions,which was 63.97% and 17.94% higher than that of treatment N0 and N2.So,for fruit-cotton intercropping pattern in Xinjiang,rational nitrogen fertilization can reduce negative effect of shading on cotton yield.