不同种植密度与留叶枝方式对三系杂交棉产量构成和产量的影响

以转基因抗虫三系杂交棉邯杂429为试验材料，设两因素（种植密度、留叶枝方式）三水平试验设计，其中，种植密度水平为2.25万株/hm2、3.75万株/hm2和5.25万株/hm2，留叶枝方式水平为不留叶枝（常规整枝， CK）、留2个优势叶枝和留全部叶枝，研究不同种植密度与留叶枝方式对棉花产量构成和产量的影响。结果表明：保留叶枝能够提高棉花的霜前花率，促进棉花早熟，但在不同的密度种植时棉产量构成和产量效应不同：低密度栽培时，保留叶枝能够显著提高单株铃数和霜前花率，最终使产量略有提高；中等密度栽培时，保留叶枝会显著降低单铃重，最终导致产量降低，其中留全部叶枝的棉花减产显著；高密度栽培时，保留叶枝会降低棉花单铃重，其中留2个优势叶枝棉花的单铃重降低显著，最终导致产量略有降低。在三系杂交棉简化整枝栽培管理中，采用种植密度3.75万株/hm2、留2个优势叶枝方式栽培棉花产量最高，籽棉产量为5383.6 kg/hm2。

Effects of Different Plant Densities and Retention of Vegetative Branches Modes on the Yield Components and Yield of Hybrid Cotton Based on Cytoplasmic Male-sterility System

Taking transgenic Bt hybrid cotton Hanza 429 based on cytoplasmic male-sterility system as the test material, three different plant densities （ 2.25 ×104, 3.75 ×104 and 5.25 ×104 plants/hm2 ） were treated without vegetative branches （ CK ） or with two or all vegetative branches to study the effects on the yield components and yield of cotton.The results showed that the retention of vegetative branches could promote the rate of pre-frost lint cotton, but the effect on yield components and yield under different plant densities was different , under low plant density, the retention of vegetative branches significantly promoted the number of the bolls per cotton and the rate of pre-frost lint cotton, finally increased the yields.Under middle plant density, the retention of vegetative branches significantly decreased the boll weight, finally decreased the yields, the retention of all vegetative branches significantly decreased the yields.Under high plant density, the retention of vegetative branches decreased the boll weight, the retention of two vegetative branches significantly decreased the boll weight, finally decreased the yields slightly.Accordingly, the yield of the retention two vegetative branches under middle plant density （ 3.75 ×104 plants/hm2 ） in hybrid cotton based on cytoplasmic male-sterility system simplified pruning cultivation was the highest, the seed cotton yield was 5 383.6 kg/hm2.