氮肥追施策略对棉花蕾铃脱落的影响

目的]施氮量对陆地棉全生育期、不同生育时期蕾铃脱落的影响.方法]研究地面灌溉不同生育时期不同施氮量下陆地棉蕾铃脱落情况的调查,结果]在棉花生育期追肥量一定情况下,追肥策略即追肥次数和分次施用量不同时,会造成总的蕾铃脱落率和各生育时期蕾铃脱落率都有差异,产量也会有不同但不足以形成显著的差异;棉花蕾期施肥对蕾铃脱落没有影响或不明显,花铃期前期施肥量要适中,过多过少都使蕾铃脱落率提高,在花铃期后期施氮越多蕾铃脱落率越高.结论]新疆中等肥力棉田采用基肥40;、蕾期追肥15;、初花期追肥23;、盛铃期或花铃期后期追肥22;的氮肥施用策略,可以使棉花蕾铃脱落率最小,产量较高.

Effect of Using Top Nitrogen Fertilizer on Abscission Rate of Cotton Buds and Bolls

Objective and Method]The present study investigated the effects of nitrogen application rate on the abscission rate of cotton buds and bolls,on the basis of the survey of the abscission rate of cotton buds and bolls at different growth period.Result]The results showed that if nitrogen application rate was too small or too large, the abscission rate of cotton buds and bolls would be different and only appropriate level of nitrogen application rate was used,there was no occurrence of serious abscission rate of cotton buds and bolls.Conclusion]When irrigation volume was 5 250 m~3/hm~2, total N-amount of was 380 kg/hm~2, basal fertilizer was 40%,the first top dressing was 15%, the second top-dressing was 23%, the third top dressing was 22%, the abscission rate of cotton buds and bolls was the smallest in Kuerle of southern Xinjiang.The top fertilization of nitrogen of 22% at the late flower bolling stage and full bolling stage,it can make the abscission rate of cotton buds and bolls be the smallest and cotton yield be the highest.