小麥葉銹病的發生與防治
一、病原:屬擔子菌亞門真(zhen)菌。夏孢子單(dan)胞,球(qiu)形至近球(qiu)形,黃褐(he)色,表(biao)面具細刺(ci),有散生發芽孔6—8個;冬(dong)孢(bao)子雙胞(bao),棒狀,頂平,柄(bing)短暗褐色。冬(dong)孢(bao)子萌發時產生4個小孢(bao)(bao)子(zi)(zi)(zi),侵染轉主(zhu)寄主(zhu),產生(sheng)(sheng)銹子(zi)(zi)(zi)器(qi)和性(xing)子(zi)(zi)(zi)器(qi)。性(xing)子(zi)(zi)(zi)器(qi)橙黃色(se),球(qiu)形(xing)(xing)(xing)至扁(bian)球(qiu)形(xing)(xing)(xing),埋生(sheng)(sheng)在寄主(zhu)表皮下(xia),產生(sheng)(sheng)橙黃色(se)橢圓(yuan)形(xing)(xing)(xing)性(xing)孢(bao)(bao)子(zi)(zi)(zi)。銹子(zi)(zi)(zi)器(qi)生(sheng)(sheng)在對應的(de)葉(xie)背病斑處(chu),能產生(sheng)(sheng)鏈狀球(qiu)形(xing)(xing)(xing)銹孢(bao)(bao)子(zi)(zi)(zi)。
二、侵(qin)(qin)染(ran)(ran)途徑及(ji)發病(bing)(bing)條(tiao)件:主要為(wei)害小(xiao)麥(mai)葉(xie)(xie)片,也侵(qin)(qin)害葉(xie)(xie)鞘(qiao)(qiao),產(chan)生皰疹狀病(bing)(bing)斑。發病(bing)(bing)初期,受害葉(xie)(xie)片正面(mian)出現圓形至長(chang)橢圓形不規則散(san)生的紅褐色夏(xia)(xia)(xia)孢(bao)子(zi)堆,少數可穿透葉(xie)(xie)片;后(hou)期在(zai)葉(xie)(xie)片背面(mian)或葉(xie)(xie)鞘(qiao)(qiao)表皮下長(chang)出排列散(san)亂(luan)的黑色冬孢(bao)子(zi)堆。該菌(jun)夏(xia)(xia)(xia)孢(bao)子(zi)萌發后(hou)產(chan)生芽管從葉(xie)(xie)片氣孔(kong)侵(qin)(qin)入,在(zai)葉(xie)(xie)面(mian)上產(chan)生夏(xia)(xia)(xia)孢(bao)子(zi)堆和夏(xia)(xia)(xia)孢(bao)子(zi),進行(xing)多次重復(fu)侵(qin)(qin)染(ran)(ran)。小(xiao)麥(mai)收獲后(hou)葉(xie)(xie)銹(xiu)菌(jun)轉(zhuan)移到自生麥(mai)苗上越夏(xia)(xia)(xia),秋(qiu)(qiu)季(ji)就近侵(qin)(qin)染(ran)(ran)秋(qiu)(qiu)苗,并(bing)向鄰近麥(mai)田傳播(bo)。秋(qiu)(qiu)苗發病(bing)(bing)后(hou),病(bing)(bing)菌(jun)以菌(jun)絲體潛(qian)伏在(zai)葉(xie)(xie)片內或少量以夏(xia)(xia)(xia)孢(bao)子(zi)越冬,冬季(ji)溫暖地區,病(bing)(bing)菌(jun)不斷傳播(bo)蔓延(yan)。小(xiao)麥(mai)返(fan)青后(hou),旬(xun)平均(jun)溫度穩定在(zai)10℃以(yi)上時,病菌(jun)侵入新生(sheng)葉片(pian)。溫(wen)(wen)度回升早(zao)(zao),并有雨露配合(he),葉銹(xiu)病提早(zao)(zao)發展(zhan),發病重。本病的發生(sheng)流行同品種、菌(jun)源、天(tian)氣等(deng)因(yin)素(su)有關。小(xiao)麥播種早(zao)(zao),出(chu)苗早(zao)(zao),發病重。冬季氣溫(wen)(wen)高(gao),雪(xue)層(ceng)厚,覆雪(xue)時間(jian)(jian)長,土壤濕度大(da)發病重。越冬菌(jun)源多(duo)、春季氣溫(wen)(wen)高(gao)、雨水多(duo),尤(you)其是(shi)小(xiao)麥抽穗(sui)前后降雨多(duo),或(huo)田間(jian)(jian)小(xiao)氣候濕度高(gao),葉銹(xiu)病往往容(rong)易(yi)流行。
三、防治方法:(1)藥劑(ji)拌種。小麥播前選用種子(zi)量0.2%的3%苯(ben)醚甲環唑懸浮種衣劑,或(huo)種子(zi)量0.06%的6%戊唑醇懸浮種衣劑拌(ban)種包衣,兼(jian)治小麥腥黑(hei)穗(sui)病(bing)、白(bai)粉病(bing)、銹病(bing)等(deng)病(bing)害。(2)噴藥防治。病(bing)葉率達10%以上時(shi),噴施20%三(san)唑酮乳油1000倍液,或12.5%烯唑醇可濕(shi)性(xing)粉劑(ji)2000倍液,重病田(tian)塊間隔10-15天(tian)連防兩次。噴藥(yao)時加入“天(tian)達2116”糧食專用型1000倍(bei)液可(ke)顯著提高防病、抗逆效果。(3)重視栽培防病(bing)(bing)(bing)措施的應(ying)用(yong)。選用(yong)抗病(bing)(bing)(bing)豐產良(liang)種;適期晚播(bo),減少秋苗發病(bing)(bing)(bing)程度(du),降低病(bing)(bing)(bing)菌越冬基數;小麥(mai)收(shou)獲后(hou)及時翻耕(geng)滅茬,清除自(zi)生麥(mai)苗,消滅當地越夏菌源;善(shan)管肥水,提高根系活(huo)力(li),增強(qiang)植株抗耐病(bing)(bing)(bing)力(li)。