生(sheng)菜(cai)褐(he)斑(ban)病(bing)是(shi)由(you)半(ban)知(zhi)菌(jun)亞(ya)門(men)的(de)萵(wo)苣(ju)褐(he)斑(ban)尾(wei)孢(bao)黴(mei)菌(jun)或(huo)香(xiang)蕉(jiao)褐(he)斑(ban)尾(wei)孢(bao)黴(mei)菌(jun)侵(qin)染(ran)引(yin)起(qi)的(de)真(zhen)菌(jun)病(bing)害(hai),主(zhu)要(yao)危(wei)害(hai)葉(ye)片(pian)。葉(ye)片(pian)上(shang)的(de)病(bing)斑(ban)表(biao)現(xian)兩(liang)種(zhong)症(zheng)狀(zhuang),一(yi)種(zhong)是(shi)發(fa)病(bing)初(chu)期(qi)呈(cheng)水(shui)漬(zi)狀(zhuang),後(hou)逐(zhu)漸(jian)擴(kuo)大(da)為(wei)圓(yuan)形(xing)至(zhi)不(bu)規(gui)則(ze)形(xing),出(chu)現(xian)褐(he)色(se)至(zhi)暗(an)灰(hui)色(se)病(bing)斑(ban),直(zhi)徑(jing)2~10毫米;lingyizhongshishenhesebingban,bianyuanbuguize,waiweijushuizizhuangyunquan。huanjingshidudashi,bingbanshangshenganhuisemeizhuangwu,yanzhongshibingbanxianghuronghe,zhiyepianbianheganku。diyizhonghebanzhengzhuangshiyouwojuhebanweibaomeijunyinqi,erxiangjiaohebanweibaomeijunzeyinqidierzhonghebanzhengzhuang。bingjunyijunsitihefenshengbaozicongzaibingcantishangyuedong,yifenshengbaozijinxingchuqinranhezaiqinran,jieqiliuheyushuijianshechuanbomanyan。zailianxuyinyuxuetianqi、植株生長不良或偏施氮肥致長勢過旺時,會導致病情的發生加重。
主要防治方法:1.清潔田園,及時把病殘體攜出園外燒毀。2.合理施肥。采用配方施肥技術,增施有機肥及磷、鉀肥,避免偏施氮肥,使植株健壯生長,增強抗病力。3.藥劑防治。發病初期可噴40%多·硫懸浮劑500倍液,或75%百菌清可濕性粉劑1000倍液加70%甲基托布津可濕性粉劑1000倍液,或50%撲海因可濕性粉劑1200~1500倍液,或60%琥乙膦鋁可濕性粉劑500倍液等,每10天左右噴灑一次,連續防治2~3次。采收前5~7天停止用藥。
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