抗虫棉保留利用营养枝的效应和技术研究

以5个抗虫棉品种为材料研究了大田条件下保留2个和全部营养枝对棉株体生长发育及产量形成的效应。结果表明,保留营养枝对棉株平均衣分、棉田病虫害发生等无明显影响,但导致果枝结铃减少、果枝铃重和全株平均铃重降低、经济系数下降等负面效应,保留营养枝越多,负面效应越大。与此同时,保留营养枝也带来了群体总铃数增多、总生物产量提高、贡献部分经济产量以及节省用工等正面效应。在本研究条件下,保留营养枝比常规整枝处理的对照增产3%～20%,保留2个和全部营养枝对皮棉产量的贡献率分别达到40%和50%以上。分析认为,在配套措施的保证下,抗虫棉保留利用营养枝是可行的。

Effects and utilization technique of vegetative branches on Bt transgenic cotton plants

Removal of vegetative branches from cotton plants is a traditional agronomic technique in China However, continual disputation has existed about this technique since it was established in 1950s With 5 Bt transgenic cotton varieties, the effects of retaining two or total vegetative branches on the growth and development of cotton plants as well as lint yield were investigated under field conditions in 2002 Results showed that there was little difference in average lint percentage and pests occurrence in cotton fields between cotton plants with and without vegetative branches Retaining vegetative branches on cotton plants caused such negative effects as reduction in economic index, boll numbers, and average weight of total bolls on the whole plant or on the fruit branches, whereas resulted in such positive effects as increase in total boll numbers and biological yield, contribution of partial economic yield, and saving some labor power for removal of vegetative branches In this field experiment, lint yield of cotton plants with vegetative branches was 3%-20% more than those without vegetative branches Retaining two and total vegetative branches contributed over 40% and 50% of the total economic yield respectivelyIn short, guaranteed with low density, wide row spacing, early fertilization and proper chemical regulation, transgenic cotton plants with vegetative branches usually bring more yield than those without vegetative branches