我们从1976年开始,经过连续4年试验,认为棉花打旁尖不是一项增产措施。1976年、1977年以不打旁尖为对照,每枝留1个果节的,水旱地平均比对照减产3 7%以上;留2个果节的,减产仅11%左右。在相同条件下,打绝旁尖后蕾铃脱落虽减少27.7—39.0%,但单株成铃却减少2.5—3.2个,内围铃重减轻0.7—1.14克,平均单铃重下降0.06—0.54克,衣分下降2.8—5.4%。原因是:①叶面积减少20%以上,植株表现早衰,叶片提前老化,早脱落10—15天;②影响根系发育,根系总干、鲜重平均减少18—36.5%,根茎径粗减少0.2—1.5毫米,降低了吸收、输送养分和水分的功能;③造成大 Since 1976, after four consecutive years of experiments, we think cotton is not a stimulant. In 1976 and 1977, with no comparison, the average output of water and dry land was 37% more than that of the control, while the remaining 2 fruit nodes were cut by only 11%. Under the same conditions, although the number of shoots dropped 27.7-39.0% after beating aside, the number of bolls per plant decreased by 2.5-3.2, the weight of bolls decreased by 0.7-1.14 g, the average single boll weight decreased by 0.06-0.54 Grams, clothing points down 2.8-5.4%. The reason is: (1) the leaf area decreased by more than 20%, the plants showed premature aging, the leaves prematurely aged and the early peeled off for 10-15 days; (2) the root growth was affected, the total root and stem weight decreased by 18-36.5% and the root diameter reduced by 0.2- 1.5 mm, reducing the absorption, transport nutrients and water functions; ③ cause large