稻田不同种群乱草形态差异及药剂防治效果比较

Morphological Differences and Response to Herbicides among Eragrostis japonica(Thunb.)Trin.Communities in Rice

调查浙江省嘉兴市和湖州市两地稻田乱草发生及危害情况,考察不同种群乱草的生物学特性差异并测定乱草对不同除草剂的敏感性差异。乱草分布及危害调查结果表明,其发生频率为5.6%~33.3%,危害等级以Ⅰ级危害为主,其中嘉兴市秀洲区、海宁市、桐乡市和湖州市安吉县等4个地区部分稻田存在Ⅱ级危害。7个不同种群乱草株高、穗长等性状比较结果表明,种群S3(浙江省桐乡市龙翔街道单桥村)的株高、穗长和剑叶长与其余种群表现差异显著,各种群间每穗粒数表现差异显著,其余性状如节数、剑叶宽和单株分蘖数各种群间差异不显著。不同种群乱草对不同药剂的敏感性测定结果表明,不同种群乱草对[口恶]唑酰草胺均表现敏感,说明[口恶]唑酰草胺可用以防治乱草,但不同种群间对[口恶]唑酰草胺的敏感性存在差异。浓度梯度试验结果表明,种群S7(安吉县递铺镇宋家湾村)对[口恶]唑酰草胺存在一定的抗性。不同种群对相同药剂表现出不同的敏感性,说明建立敏感性监测以有效防控乱草和避免其对药剂产生抗性具有重要意义。

The study was conducted to determine the occurrence,harmfulness and biological characteristics and susceptibility to herbicides of selected Eragrostis japonica communities in rice paddies of Jiaxing and Huzhou.E.japonica was found at a frequency between 5.6%and 33.3%,and its harmfulness rate as mainly gradeⅠ,while gradeⅡemerged in some areas such as Xiuzhou,Haining,Tongxiang and Anji.Plant height,grain length and other characters of seven communities were determined and compared.Community S3(Shanqiao Village,Longxiang District,Tongxiang City,Zhejiang Province)was significantly different in plant height,spike length and flag leaf length to the other communities.Other characters including node number,the flag leaf width and tillers per plant were similar among all communities.Most communities were susceptible to metamifop,indicating that this herbicide can be used to control E.japonica.However,community S7(Songjiawan Village,Dipu Country,Anji City,Zhejiang Province)was partially resistant to metamifop based on dose response bioassays.Some communities responded differently to the same pesticide,thus it is very important to establish a susceptibility monitoring program to control weeds effectively and avoid resistance to pesticides.