Abstract: In order to screen suitable cotton defoliants and mechanical harvesting modes in Changji cotton area, by taking Zhongmian M02 as the test material and using randomized block design, this paper carried out the experiment with two different mechanical harvesting modes: M1(10 cm + 66 cm + 10 cm + 66 cm + 10 cm + 66 cm), M2 (76 cm + 76 cm + 76 cm), and five defoliants: T1(detolone+ethephon), T2(ruijiao+ethephon), T3(ruituolong+ethephon), T4(kuoxiao+ethephon), T5(saideli+ethephon), and studied the influence of different defoliants on defoliation effect and fiber quality of cotton under two different mechanical harvesting modes. The result showed that: different defoliant treatments significantly increased the defoliation rate and boll opening rate, meanwhile different defoliants displayed the same defoliation effect on cotton under two different mechanical harvesting modes. Different defoliant did not show significant effect on cotton yield under the same mechanical harvesting mode, and small effect on yield components such as single boll weight, lint percentage and fiber quality. Compared with M1 machine mining mode, the defoliation rate, boll opening rate and average boll number increased significantly under M2 mechanical harvesting mode, but the yield significantly reduced. These results showed that although the single boll weight and boll number per plant of tested variety had a certain increase under M2 mechanical harvesting mode, it did not compensate for the effect of density reduction on the yield, which might be related to cotton varieties and the use technology of defoliants. Therefore, although it contributed to improve the quality of machine-harvested cotton, the application of M2 mechanical harvesting mode should fully consider the synergistic effect among varieties, density and yield. Overall considerations, T1, T2 and T3 were more suitable for popularization and application in Changji cotton area.

Key words: defoliant, mechanical harvesting mode, defoliation effect, yield, fiber quality

摘要： 为筛选昌吉棉区适宜的脱叶剂和机采模式，以中棉M02为试验材料，采用随机区组设计，设置了一膜六行宽窄行机采模式M1（10 cm+66 cm+10 cm+66 cm+10 cm+66 cm）和一膜三行等行距机采模式M2（76 cm+76 cm+76 cm），5个脱叶剂处理：T1（脱吐隆+乙烯利）、T2（瑞娇+乙烯利）、T3（瑞脱龙+乙烯利）、T4（阔笑+乙烯利）、T5（赛得利+乙烯利），研究了不同脱叶剂对两种机采模式下棉花脱叶效果及纤维品质的影响。结果表明：不同脱叶剂处理均显著提高了脱叶率和吐絮率，且不同脱叶剂对两种机采模式下棉花的脱叶效果一致；脱叶剂对同一机采模式下的产量影响不显著，对单铃重和衣分等产量构成因素以及纤维品质的影响较小；M2机采模式下的脱叶率、吐絮率、平均单株铃数均显著高于M1机采模式，但产量却显著降低，说明供试品种在M2机采模式下虽然单铃重和单株铃数得到一定的增加，但是不能弥补因密度降低对产量的影响，这可能与棉花品种和脱叶剂的使用技术相关。因此，M2机采模式虽然有利于提高机采棉品质，但在昌吉棉区推广应用需充分考虑品种、密度和产量之间的协同效应。综合考虑，T1、T2和T3更适宜在昌吉棉区推广应用。

关键词: 脱叶剂, 机采模式, 脱叶效果, 产量, 纤维品质