摘要：
The influence of four irrigation frequencies on dry matter accumulation,nitrogen absorption&utilization and agronomic traits of cotton with chemical and manual topping treatment were compared and analyzed.Xinluzao No.57 was used as the test material with four irrigation frequencies(6 times,8 times,10 times and 12 times)adopted in main plot(split-plot test design)and chemical&manual topping treatment adopted in secondary plot.The results showed that there was a positive correlation between irrigation frequency and yield,and the rapid accumulation of dry matter was pro-longed with the increase of frequency of irrigation,extending for up to 18d.Under different irrigation frequency,the pe-riod that chemical topping cotton's rapid accumulation of dry matter was 1~5 d longer than the artificial topping cotton, showing that increasing the irrigation frequency and chemical capping both prolonged the rapid accumulation period of dry matter,increased the accumulation of dry matter and the amount of nitrogen uptake.Under different irrigation frequency, the abscission rate of chemical topping cotton buds and bolls was 2.47% ~9.21% higher than artificial topping cotton. Under chemical topping and artificial topping,the changes of single boll weight were 0.06~0.49 g and 0~0.28 g re-spectively,and the changes of seed index were 0.19~1.67 g and 0.11~0.81 g.These indicate that chemical topping cotton plants are more sensitive to water and fertilizer,and that chemical topping can prolong the growth period of cotton plants to make cottonseed more full and have high quality breeding potential.%试验比较分析4种不同灌水频次对化学封顶与人工打顶棉花干物质积累、氮素吸收利用及农艺性状的影响.选用新陆早57号作为试验材料,采用裂区试验设计,主区为6次、8次、10次、12次4个灌水频次,副区为打顶方式,分为化学封顶、人工打顶.研究发现:灌水频次与产量呈正相关,且随着灌水频次的增加干物质快速积累时期延长,最多延长18 d.不同灌水频次下,化学封顶棉花干物质快速积累时期较人工打顶长1~5 d,说明提高灌水频次和化学封顶均能使棉株干物质快速积累持续时间延长、积累量增大,同时使氮素吸收量增多.不同灌水频次下,化学封顶棉花蕾铃脱落率较人工打顶高2.47% ~9.21%,化学封顶及人工打顶单铃重分别为0.06~0.49 g和0~0.28 g,籽指分别为0.19~1.67 g和0.11~0.81 g,说明化学封顶棉株对水肥更加敏感,化学封顶能延长棉株生育期使棉籽更加饱满,有优质育种潜力.
