棉花从开花到吐絮这段时间称为花铃期,我省一般为7月上旬到8月底,历时50天左右.在棉花的一生中,花铃期生长发育最为旺盛。据测定,此期吸收 N,P、K 的数量分别占全生育期吸收量的63—79%、75%、78%;耗水量占一生总耗水量的45—65%;干物质积累占全生育期总量的70—80%,也是构成产量、抓“三桃”的关键时期。棉花花铃期的生理变化复杂,各种矛盾表现突出,必须掌握其生育特点,采取相应的管理措施,促使多结铃少脱落。初花期:是营养生长与生殖生长齐头并进时期,据我们在五里扬多年调查,主茎平均日增长量为2.67厘米,生长过旺的棉田可达3—4厘米,株高伸长为整个株高的三分之一左右。叶面积的增加也较快,7月13日 Cotton flowering from the flowering to the time known as the boll flowering period, the province is generally early July to the end of August, which lasted about 50 days in the cotton’s life, the most vigorous flower growth. It was determined that the amount of absorbed N, P and K in this period accounted for 63-79%, 75% and 78% of the total growth during the whole growth period respectively; the water consumption accounted for 45-65% of the total water consumption in a lifetime; the dry matter accumulation accounted for 70-80% of the total growth period is also a key period that constitutes production and grasps the “Three Peaches.” Cotton flower boll period of physiological complex changes, all kinds of contradictions outstanding performance, we must master its reproductive characteristics, take appropriate management measures, prompting more knot less off. First flowering: vegetative and reproductive growth go hand in hand, according to our many years of investigation in Wully Yang, the average daily increase of 2.67 centimeters of main stem, over-grown cotton fields up to 3-4 cm, the plant height elongation of the entire strain About one third of the high. The increase in leaf area is also faster, July 13