Abstract: Effects of spraying different concentrations of flumetralin solution instead of topping on cotton variety Zhongmiansuo 50 in topping period were studied. The results showed that after using flumetralin, the plants grew vigorously; the leaves showed invisible green and the plant height decreased, and the top leaves became smaller. The seed index, single boll weight and yield of seed cotton all increased. Lint cotton weight increased in the flumetralin concentration of 0.10 or 0.08 g·L-1. There was no significant difference in yield and quality traits of cotton among different treatments. It can be concluded that cotton topping can be replaced by spraying flumetralin solution, which can achieve effects of cotton topping and pruning, avoid physical damage and save labor and time.

Key words: flumetralin, cotton topping, yield, quality