留叶枝去早果枝对抗虫棉生长发育及产量的影响

为探索留叶枝去早果枝对抗虫棉生长发育和产量的影响，于2004—2005年以两个不同熟性的抗虫棉品系K640和K9918为材料，在济南和临清进行了留叶枝去早果枝试验研究。结果表明，与正常整枝（去叶枝）相比，留叶枝去早果枝显著促进了两个品系的株高增长和叶面积扩展，叶面积系数提高了24%~94%。早熟品系K640在2004年和2005年分别比正常整枝增产7.4%和15.6%，而中早熟品系K9918的产量在2004年与正常整枝相当、2005年减产12.0%。留叶枝去早果枝显著减少了伏前桃比例，而相应提高了伏桃和秋桃的比例。留叶枝去早果枝对平均衣分影响不大，但显著影响铃数。分析认为，留叶枝去早果枝对棉花生长发育和产量的效应主要是通过提高叶源、降低库源比实现的，只有在叶源相对不足的情况下采取该措施才有增产作用。

Effects of Retention of Vegetative Branches and Removal of Early Fruiting Branches on the Growth and Development and Yield of Bt transgenic Cotton

Two cotton lines with varying maturity, K640 (short season cotton line) and K9918 (spring cotton line ), were grown in Jinan and Linqing in 2004 and 2005, and the effects of retention of vegetative branches (VB) plus removal of early fruiting branches (FB) on plant growth and development, and yield were examined each year. Results showed that retention of VB and removal of FB promoted the plant height and the leaf source, and the leaf area index was increased by 24-94% relative to the VB-removal control. Retention of VB plus removal of FB increased the yields of K640 by 7.4% and 15.6% in 2004 and 2005 respectively, whereas the yield of K9918 was similar to that of control in 2004, and was decreased by 12.0% in 2005. Retention of VB plus removal of FB reduced the percentage of bolls formed pre-summer, but increased those of bolls formed in summer and autumn significantly. Retention of VB plus removal of FB had no significant effect on lint percentage, but significantly affected the boll numbers per ground area and boll weight. It was concluded that effects of VB retention and FB removal on plant growth and development and cotton yield are mainly attributed to the enhanced leaf source and reduced sink/source ratio. Yield increase was only achieved when leaf source of plant population is relatively insufficient.