种植密度对机采麦套棉产量形成及品质的影响

【目的】 研究机采麦套短季棉种植模式下不同种植密度对棉花产量和品质的影响，为麦棉两熟种植模式下机采短季棉适宜密度的选择提供依据。【方法】 于2019年选择早熟品种锦科707（JK707）和鲁棉2387（LM2387）为材料，进行大田试验，设置3个密度梯度（4.5×10⁴株/hm²（D₁）、9×10⁴株/hm²（D₂）、13.5×10⁴株/hm²（D₃））。【结果】 随密度增加，株高、果枝台数和节枝比逐渐降低，而叶面积指数（LAI）和生物量则逐渐增大，JK707和LM2387的LAI均以D₃ 最大，分别为3.14和4.16。JK707、D₂和D₃较D₁生物量分别增加40.4%和42.0%；LM2387、D₂和D₃较D₁生物量分别增加65.5%和85.1%。随密度升高，籽棉产量先升高后降低，2个品种均以D₂种植密度产量最高（JK707和LM2387分别为4 025和4 114 kg/hm²）。与JK707相比，LM2387皮棉产量在中高密度（D₂和D₃）下更具优势。纤维马克隆值随密度增加逐渐下降，纤维强度以D₂最优。JK707的纤维长度、强度和马克隆值均优于LM2387。【结论】 在黄河流域机采麦套短季棉种植模式下，早熟棉品种锦科707和鲁棉2387在种植密度D₂（9×10⁴株/hm²）下能够实现优质高产。锦科707纤维品质优，而鲁棉2387衣分高，且株型更紧凑，成铃更集中，更适宜机械化采收。

Effect of Densities and Varieties on Yield and Quality of Mechanical-harvested Cotton Interplanted with Wheat

【Objective】 To study the effects of different densities and varieties on yield and quality of cotton under the short-season cotton for the wheat-cotton double cropping system and provided the basis for selection and breeding of suitable densities and varieties of short-season cotton for the wheat-cotton double cropping system. 【Method】 A field experiment was conducted in 2019 with the density gradients of 45，000 plants/hm² （D₁），90，000 plants/hm² （D₂） and 135，000 plants/hm² （D₃） were set up in Anyang，Henan Province，with early maturing varieties Jinke 707 （JK707） and Lumian 2387 （LM2387） as experimental materials.【Result】 With the increase of densities，the plant height，the number of fruit branches and the ratio of branches gradually decreased，while the Leaf Area Index （LAI） and biomass where gradually increased，the LAI was the largest under D₃，with the maximum of 3.14 and 4.16，respectively. The total biomass of D₂ was increased by 40.4% and 42.0% than that of D₃ and D₁ when compared to the three density treatments of the JK707 varieties and were increased by 65.5% and 85.1% under the three density treatments of the LM2387 varieties. With the increase of densities，the seed cotton yield was first increase then decrease，with the D₂ densities the highest （JK707 and LM2387 were 4 025 kg/hm² and 4 114 kg/hm²，respectively）. Compared to the JK707，LM2387 have more advantages in the medium and high densities. The micronaire value of fiber decreases gradually with the increase of density，and the fiber strength was highest under the D₂ densities. The fiber length，strength and micronaire value of JK707 are better than LM2387.【Conclusion】 In summary，under the short-season cotton cropping pattern of the wheat-cotton double cropping system in the Yellow River Basin，the varieties JK707 and LM2387 can achieve high quality and high yield under the planting density of D₂ （90，000 plant s/hm²）. Compared with the two varieties，JK707 fiber quality is superior，while LM2387 has a higher lint，more combatively plant type，more concentrated bolls，and were more suitable for mechanized harvesting.