yumisiheisuibingsuchengwumihuoyayumi,zaiwoguobeifangchunyumiqufabingjiaozhong。ganbingyoumiao,zaidisiyehediwuyeshangyanzhongmaichuxianyuanxinghuochangfangxingdetuilvbandian,zhijing1~2毫米。成株期在雌穗和雄穗顯現典型症狀,感病雄穗花序變黑、花器變形,穎片變長呈葉片狀,後期菌癭破裂散落黑粉;感(gan)病(bing)雌(ci)穗(sui)比(bi)健(jian)穗(sui)短(duan),下(xia)部(bu)膨(peng)大(da)頂(ding)部(bu)較(jiao)尖(jian),後(hou)期(qi)整(zheng)個(ge)雌(ci)穗(sui)變(bian)為(wei)一(yi)團(tuan)黑(hei)褐(he)色(se)粉(fen)末(mo),中(zhong)間(jian)夾(jia)雜(za)黑(hei)色(se)絲(si)狀(zhuang)物(wu)。有(you)時(shi)苞(bao)葉(ye)變(bian)狹(xia)小(xiao),簇(cu)生(sheng)畸(ji)形(xing)。絲(si)黑(hei)穗(sui)病(bing)菌(jun)是(shi)由(you)厚(hou)垣(yuan)孢(bao)子(zi)侵(qin)染(ran)引(yin)發(fa),屬(shu)係(xi)統(tong)性(xing)侵(qin)染(ran)的(de)土(tu)傳(chuan)病(bing)害(hai),但(dan)亦(yi)可(ke)通(tong)過(guo)種(zhong)子(zi)傳(chuan)播(bo)。土(tu)壤(rang)、糞肥或種子上越冬的厚垣孢子是翌年初侵染源。北方自然條件下,厚垣孢子可在土壤中存活2~3nian。houyuanbaozimengfahou,zaiyumiyoumiaoqiqinru,zhujiandaodashengchangdian。suiyumizhizhushengchangfayu,jinruhuayahesuibu,bingzuizhongxianzhengzaochengweihai。gaibingyizailengliangdiqufabing,yumilianzuoshijianchang、土壤幹旱、溫度低、玉米出苗緩慢均有利於該病的發生。
yumisiheisuibingshijuechanxingbinghai,fabinglvdengyusunshilv,yinci,zaibeifangchunyumiquyaotebiezhongshigaibinghaidefangkonggongzuo。fangkongcuoshizhuyaobaokuoyixiajigefangmian:
(1)選用抗病品種。
(2)適期搶墒播種,防止出苗緩慢。
(3)施用充分腐熟的農家肥,防治肥料帶菌。
(4)做好種子包衣,藥劑可選用2%戊唑醇可濕性粉劑,或15%三唑酮可濕性粉劑,劑量為種子重量0.4%-0.6%。
(5)在發病早期及時拔除病株,顯症後在菌癭破裂前,徹底清除病株並深埋或燒毀,防止越冬孢子散落增加來年的病原基數。