北疆植棉区滴灌量对化学打顶棉花植株农艺性状及产量的影响

【目的】探索滴灌量变化对化学打顶棉花农艺性状及产量的影响,为棉花化学打顶技术的应用提供依据。【方法】2016年,田间自然条件下,以人工打顶作为对照,选用氟节胺复配型和缩节胺复配型两种打顶剂,分别设3种不同滴灌量,通过测定不同处理棉花农艺性状、机采前脱叶效果及产量变化,分析不同滴灌量条件下棉花化学打顶株型变化及产量效应。【结果】打顶处理与滴灌量处理对棉花株高及果枝长有显著的互作效应,其中化学打顶×中滴灌量组合较化学打顶×高滴灌量组合株高平均降低6%,果枝长平均变短12%,产量差异不大;而较化学打顶×低滴灌量组合株高增加13%,果枝长平均增加14%,籽棉产量却增加7%。化学打顶与人工打顶之间脱叶率及杂叶率无显著差异,而较低的滴灌量可以加快化学打顶棉花的脱叶进程。与人工打顶相比,化学打顶虽显著降低了上部果枝铃重,但对衣分及产量无显著影响。【结论】喷施打顶剂后的2次灌水控制在中滴灌量(32 m3·667 m~(-2)),不仅可以调节化学打顶棉花的株型和脱叶进程,还可以在不降低籽棉产量的同时减少滴灌量,生产上具有一定的应用价值。

Effect of Drip Irrigation Amount on the Agronomic Traits and Yield of Cotton Grown with a Chemical Topping in Northern Xinjiang,China

Objective] The aim of this study was to examine the effects of drip irrigation amount on the agronomic traits and yields of cotton plants grown using a chemical topping,which may have implications for the application of chemical topping technology during cotton production.Method] Two-factor experiments with three drip irrigation treatments and two topping methods were conducted under field conditions during the cotton-growing period in 2016.We used manual and chemical topping methods.Flumetralin and DPC topping agents were selected for the chemical topping.Agronomic traits,defoliation state before machine harvesting,and changes in yield were assessed to clarify the effects of chemical toppings following different drip irrigation treatments.Result] There was a significant interaction between the topping methods and drip irrigation amount,which influenced cotton plant height and branch length.For the chemically topped cotton plants,the average plant height and branch length under the middle drip irrigation treatment were 6％ and 12％ lower,respectively,than those under the high drip irrigation treatment,but were 13％ and 14％ higher,respectively,than those under the low drip irrigation treatment.There were no significant differences in the effects of the middle and high drip irrigation treatments on the yield of chemically topped cotton plants.In contrast,the cotton yield of chemically topped plants was 7％-8％ higher under the middle drip irrigation treatment than that under the low drip irrigation treatment.There were no significant differences in the defoliation rate and amount of miscellaneous leaves between the chemical and manual topping methods.However,the low drip irrigation treatment may have increased the defoliation rate in the chemically topped cotton.Although the chemical topping method significantly decreased boll weight from the upper branches,it had no significant effect on the final yield and lint percentage.Conclusion] Two rounds of a middle drip irrigation treatment (32 m3· 667 m-2) after spraying plants with a topping agent may affect plant growth and decrease the defoliation rate of chemically topped cotton plants.Furthermore,the middle drip irrigation treatment does not appear to decrease seed cotton yields.Therefore,spraying plants with a topping agent and applying the middle drip irrigation treatment may be beneficial for cotton production.