种植密度对棉花主要群体质量指标的影响

 以转基因抗虫棉农大棉8号为试验材料，设置6个密度水平，研究密度对棉花群体干物质量、LAI、叶层配置及透光率、总铃数等主要群体质量指标的影响。结果表明，最终干物质量以8.7万株·hm^-2最大，达11735 kg·hm^-2；高密度群体最大LAI出现时间比低密度群体早13天左右，但群体透光率以低密度群体较高；结铃率随密度的增加而降低，以1.5万株·hm^-2最大，达43.5%；群体果节量和总铃数分别以10.5万株·hm^-2和6.9万株·hm^-2的群体最多，分别为323.05万个·hm-2和74.06万个·hm^-2；子棉产量以6.9万株·hm^-2最高，为3810.33 kg·hm^-2。只有各群体指标均相对较优才能构成高产群体。

Effects of Different Densities on Main Population Quality of Cotton

Using insect-resistant transgenic cotton Nongdamian 8 as material, population quality indexes such as dry matter accumulation, leaf area index (LAI), leaf distribution, canopy light transmission and total boll number per area were studied under six densities. The results indicated that the maximum dry matter accumulation was 1735 kg·hm^-2, which occurred in the treatment of 8.7×10⁴ plants per hectare. The maximum LAI in high density canopy appeared about 13 days earlier than that of in low density canopy, but the light transmission in the low density canopy was better. The rate of boll setting decreased as the density increased, up to 43.5% under the treatment of 1.5×10⁴ plants per hectare. For the number of fruit-nodes and total boll, the optimum were 3.2305×10⁶ plants per hectare and 7.406×10⁵ plants per hectare, appeared in the treatment of 1.05×10⁵ plants per hectare and of 6.9×10⁴ plants per hectare, respectively. The seed cotton yield was highest (3810.33 kg·hm^-2) in 6.9×10⁴ plants per hectare. A high-yield group can form only if colony indexes were comparatively better.