马唐、旱稗、牛筋、狗尾等禾本科杂草,是我县棉田的主要优势草种,在棉花苗期常常出现“草欺苗”的现象,严重影响棉花正常生长。本地常年多用土壤处理型除草剂——氟乐灵等进行防除,往往是防除杂草对象田块不明确、防除适期短。又与棉花、播种争劳力抢时间,容易错过防除适期。同时又遇霉雨季节,影响药效,导致防除效果不稳定,田间草害未能得到应有的控制。1985～1986年我站应用新型除草剂,改 Crabgrass, arid barnyard, tendon, dog tail and other grass weeds, is the dominant cotton in our county grass species, cotton seedling often appear “grass bullying” phenomenon, seriously affecting the normal growth of cotton. Local perennial use of soil-processing herbicide - trifluralin and other prevention and control, often against weeds targeted field is not clear, short-term control. And cotton, sow the labor struggle to grab time, easy to miss the appropriate period of control. In the meantime, the rainy season also affects the efficacy, leading to the instability of the control effect and the grass control in the field. From 1985 to 1986, I applied a new type of herbicide and changed it