上海市金山区单季稻田杂草发生及防除措施

通过田间普查和问卷调查以及大农户、技术员和专家讨论会等方式．对近年来金山区单季晚稻田杂争种类、发生情况、防除现状进行了调查。结果发现水苋菜、千金子为当前直播稻田优势危害种类．假稻、杂草稻危害程度上升速度较快，已成为稻田主要危害种类之一.并针对当前除草技术掌握难度大、防除成本高等技术难题提出了建议和思考。

The weed occurrence and control in single-crop late rice field in Jinshan District of Shanghai

The weed species and their occurrence in the single-crop late rice field in Jinshan District of Shanghai in recent years and the weeding techniques were investigated by means of field survey,questionnaire,and symposium attended by influential farmers,technicians or experts.The investigation showed that Ammannia baccifera and Leptochloa chinensis became dominant species damaging direct-seeding rice,and Leersia hexandra var.japonica and plants of miscellaneous rice varieties rapidly increased in injurious effect and became major injurious weeds.Some suggestions were put forward in dealing with the present problems such as weeding techniques difficult to be mastered and high weeding cost.