辽河流域棉区棉花化学封顶技术应用研究

为了探索化学封顶技术在辽河流域棉区的应用可行性和配套技术,2015-2020年,在辽宁省经济作物研究所进行比较试验。选用中国农业大学植物生长调节剂教育部工程研究中心提供的化学封顶剂（简称封顶剂）,设置7月12日（T1）和7月17日（T2）2个封顶时间,750、1125和1500mL/hm² 3个封顶剂用量,同时设120g/hm²高浓度甲哌鎓（DPC）处理,以不打顶为对照,以人工打顶和打大顶为副对照。结果表明,化学封顶处理能够有效控制植株长势,使株型更加紧凑,构造合理冠层结构;处理时间越早,控长效果越好。不同浓度药剂处理的效果也有差别,但差异不显著。不同化学封顶处理对产量及其构成因素影响程度不同,各处理之间纤维品质差异不显著。结论认为,化学封顶剂的种类、喷施时间和用量都会影响封顶效果,辽河流域棉区建议在7月17日左右进行化学封顶处理,封顶剂浓度以1125mL/hm²为宜。

Study on Cotton Chemical Topping in Liaohe Cotton Area

In order to explore the feasibility of chemical topping in Liaohe cotton area and supporting technology, comparison experiment was conducted in Liaoning Cash Crop Institute in 2015-2020. Choosing chemical topping agent (short for topping agent) provided by Plant Regulation agent Engineering Research Center of Education Ministry in Chinese Agricultural University, two topping times July 12th and 17th, three concentrations (750, 1125 and 1500mL/ha) were set, together with high concentration DPC 120g/ha, and taking no-topping as control, artificial topping and strong topping as deputy control. The results showed that chemical topping treatment could effectively control the development of plant height and upper branch length, making plant type more compact, forming reasonable canopy, while earlier topping caused more notable topping result. The effects of different concentrations were different, but the differences were not significant. The effects of different topping treatments on yield and its components were different, the difference of fiber quality were not significant between treatments. In conclusion, the type, spraying time and concentration of chemical topping agent will affect the effect of topping. In Liaohe basin cotton area, chemical topping treatment is suggested around July 17th, with the concentration of 1125mL/ha.