钾肥用量对棉花蕾铃脱落及产量品质的影响

目的]研究不同钾肥用量对棉花生育期蕾铃发生与脱落的动态变化、产量构成因素和品质指标的影响.方法]通过田间小区试验,在氮肥、磷肥和微肥用量相同情况下,设4个钾肥用量处理,即0、30、60、90kg/hm2 K2O.结果]施钾可提高棉花上部(9～12)果枝上的现蕾数或降低下部(1～4)果枝和上部(9～12)果枝的蕾铃脱落率；同时,施钾可增加棉花各个果节的现蕾数和有效铃数,降低棉花1、2果节棉花蕾铃脱落率.蕾铃总脱落率在7月2～15日出现第1次高峰,8月2～16日出现第2次高峰.施钾显著增加棉花单株铃数和皮棉产量,由棉花钾肥的效应方程,推荐K2O量为48.6 kg/hm2.施钾在一定范围内可增加棉花的长度、比强、伸长率以及可纺系数,随着钾肥施用量的增加棉花整齐度、马克隆值也增加.结论]施钾显著增加了棉花现蕾数和有效结铃数,降低棉花蕾铃脱落率.现蕾数、有效铃数与施钾量呈显著的正相关,而蕾铃脱落率与施钾量达到了显著的负相关.施钾可显著提高棉花皮棉产量,改善棉纤维品质.

Bud & Boll Falling,Yield and Quality of Cotton Affected by Rates of Potassium

【Objective】The field experiment was conducted to study the bud and boll falling,lint yield and fibre quality of cotton affected by different rates of potassium.【Method】When the same rates of nitrogen,phosphorus and microelement fertilizer were applied,4 potassium rates were designed as following: 0,30,60 and 90 kg /hm~2 K_2O.【Result】Applied potassium can increase bud number in the 9th - 12th fruit spur and reduce the bud and boll falling ratio in the 1st - 4th and the 9th - 12th fruit spur.Meanwhile potassium can increase available bud and boll number and reduce bud and boll falling ratio in the 1st and 2nd fruit node.The first bud and boll falling peak is from July 2 to 15 and the second peak is from 2 to 16 of August.Applied potassium can increase boll number of per plant and lint yield significantly.According to equation of potassium domino offect,the recommended potassium fertilizer is 48.6 kg/hm~2 K_2O.Potassium can increase lint length,strength,extension rate and spinning coefficient at some applied potassium range. Lint length uniformity and micronaire value will increase as potassium rate increases.【Coildlision】Applied potassium can increase available bud and boll number and reduce bud and boll falling ratio.Bud number and available boll number have significantly positive correlation with potassium rates,and bud and boll falling rate has significantly passive correlation.Applied potassium can increase lint yield significantly and improve lint quality.