上海市麦田杂草的发生、危害现状和防除对策

1999～2000年连续2年用5j最取样法及五级目测法对上海地区麦田杂草种类、群落结构及其危害程度进行了普查，用相对密度、相对均度、相对频率、相对多度等参量指标对普查资料进行汇总，并与1982年的杂草普查资料相比较。结果表明：经过近20年，麦田杂草种类有较大幅度下降，共有39种，分属15科；麦田杂草的优势种出现了相应变化，按相对频率参量指标分析，依次为日本看麦娘（Aloperurus japonicus Steud)、网草Beckmannia syzigachne(Steud．) Fernald．]、硬草Sclerochloa kengiana(Ohwi．）Tzvel．]、看麦娘(Alopecurus aequalis Sobol.)、猪殃殃Galium qparine var．terterttra(Glen．et Godr．)]、牛繁缕Stellaria media(L.)Cyrill．]、大巢菜(Vicia saliva L．)、早熟禾(Poaannua L．)。麦田杂草的群落发生了变化。主要以禾本科杂草为主；通过化除后，麦田杂草的危害处于中等偏低水平状态。危害指数在3级以下。根据麦田杂草发生危害的现状，提出了我市今后稻田杂草治理的策略：实施以化学防除为主体的综合治理方法，将单纯的化学防除与系统的农业、机械等防治措施有机地结合运用，控制麦田杂草的危害。

Development,Status of Damage and Control Strategy of Cornfield Weed in Shanghai

Species,community,and harm of weed in cornfield of Shanghai were investigated by sampling method from 5poin ts and 5grade eyeballing method from 1999to2000.The parameters index includin g Relative Density(RD),Relative,Uniformity(RU),Relative frequency(RF)and Relative Abundence(RA),were collected and were compared wi th the data in 1982.The result showed that the species of cornfield weed re duced evidently after about 20years,now there was 39species of weed belo nged to 15families.The predominant species of weed chan ged,in turn,Aloperurus japonicus Steud,Beckmannia syzigachne(Steud.)Fernald,Scle-rochloa kengiana(Ohwi.)Tzvel.,Alopecurus aequalis Sobol.,Galium qparine var.tenerum(Gren.et Godr.),Stellaria media(L.)Cyrill.,Vicia sativa L.,Poa annua L.The community of cornfield weed also changed,the weed of standing grain was the predominant species.After the weed was treated b y chemistry agents the damage of weed in cornfield maintained the middlin g level,the damage index was under 3th grade.The strate gy of controlling the cornfield weed for the future in Shanghai was put forward according the present situation of the cornfield w eed,which includes synthetic method of controlling the weed treated mainly by chemistry prepara-tion;united application of chemistry treatment and prevention and cure of systemic agriculture and machine to control the damage of cornfield weed.