Research on Cotton Agronomic Traits and Chemical Topping Effect after Spraying Flumetralin

【Objective】To study the agronomic and economic characters of cotton by using different topping measures in Xinjiang cotton area and to explore the problems in chemical topping and provide theoretical basis for chemical topping.【Method】Xinluzao 33,Xinluzao 45 and Xinluzao 46 were used as test materials, chemical topping,manual topping,on- decapitation were set up to study the cotton agronomic and economic characters change under three kinds of topping measure.【Result】Chemical topping cotton height was significantly higher than that of the manual topping and lower than that of the non- decapitation,but the number of main stem nodes and fruiting branches was significantly higher than that of the manual topping. Fruit branch length was below the manual topping,and thus more compact plant type. The boll number upon fruiting branch and the inner boll number treated by chemical topping is slightly higher than that of the manual topping,and there was a significant difference in boll weight. The yield of the seed cotton and ginned cotton was roughly the same of that of the manual topping. 【Conclusion】Fluorine could effectively control cotton top growth and meanwhile made cotton plants more compact.