日前,黑龙江省依兰县农民来电,说他家的一块老稻田地里的野慈姑特别多,以前用药也好使,可最近两年效果好像不如以前了,想问问这是为啥?专家认为,过去水田野慈姑的防除没有问题,插秧前用磺酰脲类除草剂苄嘧磺隆或吡嘧磺隆封闭处理,使用低量即可取得较好 Recently, the farmers in Yilan County, Heilongjiang Province, called and said that he had an unusually large number of wild arrowheads in an old paddy field in his homeland. Her previous medication was so good that her effects in the past two years seemed to be less than before. I would like to ask why this is an expert. In the past, there was no problem with the prevention and cure of the field wild arrowheads. Before the transplanting, the sulfonylurea herbicide, bensulfuron-methyl or pyrazosulfuron-ethyl,