不同播期与打顶时间对麦(油)后直播短季棉产量及纤维品质的影响

Effects of Seeding Date and Topping Date on Yield and Fiber Quality of Short-Season Cotton Field-Seeded after Barley(Rape)/Wheat Harvest

【目的】探索播期与打顶时间对麦(油)后直播短季棉产量、产量特性及纤维品质的影响。【方法】以中棉所50为材料,采用裂区设计,研究不同播期(月-日)(S_1,05-25;S_2,06-10)和打顶时间(月-日)(T_1,07-30;T_2,08-07;T_3,08-15)对长江流域下游植棉区麦(油)后直播短季棉产量和纤维品质的影响。【结果】播期间,皮棉产量和霜前花率及铃数、铃重和衣分均以S_2条件下较低;果枝数和果节数以S_2条件下较低而成铃率以S_1较低。打顶时间间,皮棉产量和霜前花率随打顶时间推迟而降低;果枝数、果节数及节枝比随打顶时间推迟增加而成铃率降低。互作显示,皮棉产量与霜前花率均以S_1T_1处理较高;果枝数和果节数以S_1T_1、S_1T_2和S_1T_3处理较高,成铃率以S_2T_1和S_1T_1较高。相关性分析表明,皮棉产量与果枝数、果节数、铃数显著正相关,但与节枝比、成铃率相关不显著。此外,播期间,以S_2条件下棉株下部和中部果枝成铃分布比例较高而上部较低;打顶时间间,下部和中部果枝成铃分布比例随打顶时间推迟降低而上部增加。就棉铃纤维品质而言,S_1T_1处理不同果枝部位棉铃的纤维长度、纤维比强度和中部马克隆值均较优。【结论】长江流域下游植棉区,麦(油)后直播短季棉于5月25日播种、7月底打顶有利于其高产、稳产和优质。

[Objective] The aim of this study was to evaluate the effects of seeding date and topping date on yield, yield characteristics and fiber quality of short-season cotton（CCRI 50） field-seeded after barley（rape）/wheat harvest. [Method] A split-plot design with three replicates was used for the study in Nanjing, Jiangsu province of China in 2014-2015. The main plots comprised two seeding dates（S_1： 25 thMay and S_2： 10 thJune）, while topping dates（T_1： 30 thJuly, T_2： 7 thAugust and T_3： 15 thAugust） constituted the subplots. [Result] The lint yield, the ratio of yield before frost, boll number, boll weight and lint percent of S_2 were lower than those of S_1. The number of fruit branches and fruit nodes of S_2 were less than those of S_1 while it was the opposite for the boll setting ratio. The lint yield and the ratio of yield before frost decreased with the delay of topping date. The number of fruit branches and fruit nodes, the ratio of them increased with the delay of topping date while the boll setting ratio decreased. The interaction of sowing date × topping date showed that the treatment of S_1 T_1 achieved higher value in lint yield and the ratio of yield before frost. The higher number of fruit branches and fruit nodes were found at the treatment of S_1 T_1, S_1 T_2 and S_1 T_3 and higher boll setting ratio were found at the treatment of S_2 T_1 and S_1 T_1. Correlation analysis showed that the lint yield positively and significantly correlated with the number of fruit branches and fruit nodes and boll number, but did not significantly correlate with boll setting ratio and the ratio of fruit branches number to nodes number. In addition, the boll distribution ratios of middle and low fruit branches of S_2 were more than those of S_1 while it was the opposite for that of up fruit branches. The boll distribution ratios of middle and low fruit branches decreased with the delay of topping date while it was the opposite for that of up-fruit branches. The treatment of S_1 T_1 could be better to improve fiber length and fiber strength of different fruit branches and the micronaire value of middle fruit branches. [Conclusion] The treatment of S_1 T_1 is conducive to high yield and fiber quality of short-season cotton field-seeded after barley（rape）/wheat harvest in lower reaches of the Yangtze River.