Abstract: In order to clarify the regulation effect of planting density and chemical control on the fiber quality for direct-seeded cotton after wheat harvest, the short season cotton cultivar ‘Guoxinzao 11-1’ was used as the experimental material, the effects of planting density combined with growth regulator (Miantaijin) on the fiber quality of direct-seeded cotton after wheat harvest was studied in cotton growth season. The results showed that fiber length and fiber strength gradually decreased with the increasing of planting density, but the length, micronaire and strength of fiber increased with the increasing of Miantaijin application dose. The fiber located in the upper parts of canopy exhibited a higher strength under low density than that under higher density. Thus, the application of 1 170 mL/hm2 Miantaijin promoted the fiber strength in the middle and lower parts. Under medium and high density, treatment with 1 170 mL/hm2 Miantaijin application showed an optimum range of micronaire value of all cotton plant parts. In conclusion, the whole plant fiber quality was improved under treatment of 90 000 plants/hm2 combined with 1 170 mL/hm2 Miantaijin application. Moreover, the fiber micronaire value, the fiber length, strength, and maturity of the upper and lower part of the cotton plant were also improved under this treatment.

Key words: direct-seeded cotton after wheat harvest, planting density, chemical regulation, fiber quality

摘要： 为明确种植密度和化控对小麦后直播棉纤维品质的调控效应，以特早熟品种‘国欣早11-1’为研究材料，研究种植密度配合棉太金化控对小麦后直播种植方式下棉纤维品质的影响。结果表明：随着种植密度的增加棉纤维长度、比强度逐渐降低，马克隆值、纤维长度和比强度受棉太金调控效应较为明显。低种植密度下上部棉纤维比强度高，棉太金施用量为1 170 mL/hm2有利于中下部棉纤维比强度的提高。中高种植密度下棉太金施用量为1 170 mL/hm2时，有利于棉株各部位纤维马克隆值保持在适宜范围内。综上，在密度为90 000株/hm2、棉太金化控用量1 170 mL/hm2时有利增强棉花整株的纤维品质，且有利于棉株上部和下部纤维马克隆值的优化，及纤维长度、纤维比强度和成熟度的提高。

关键词: 小麦后直播棉, 种植密度, 化学控制, 纤维品质