棉花株间竞争对铃重及成铃数的影响

在黄淮海气候生态条件下，研究了种植密度对棉花不同部位铃重和结铃数的影响，探讨了黄淮海地区棉花产量进一步提高的途径。结果表明：在正常气候年份下，低密度1.5万株/hm2与高密度9万株/hm2处理下均不利于群体产量的提高，中等密度6万株/hm2处理下群体产量则能够保持较高水平。试验表明，增加密度能增加单位面积总铃数，但密度过高削弱了棉株个体发育，造成单铃重降低，不利于提高棉产量。棉铃在不同密度处理下均集中于3~10果枝，因此提高中部果枝铃重对棉花生产意义很大。农业生产中要注意个体与群体的平衡以获取最高经济效益。

Study on Cotton Mutual Influences on the Number and Weight of Bolls

On the basis of the experiment in 2004, we could find that ,under the common meteorological condition in the Huang-Huai-Hai plain, the growth density of cotton had great influences on the number of bolls at different position, as well as theirs weight. The results showed that, with the normal climate condition, the low-density (15,000 plants/hm2) and high-density (90,000 plants/hm2) were both not good at increase the yield, and the moderate density (60,000 plants/hm2) could increase the yield obviously. From the results we can also see that, the increased density was help to increase the total number of bolls per hm2, but with the cost of influencing growth of single plants, decreasing the weight of single boll which thus had some influences on cotton yield. We could still see that most of bolls, whatever the growth density were, were concentrated from the second branches to the eighth branches which we call mid-branches. Therefore, it was very important to increase boll weight at mid-branches and find the optimal mode between single and population in the cotton produce.