導(dao)語：水(shui)稻惡苗病(bing)防治一文(wen)來(lai)源(yuan)于網友上傳，不代表本站(zhan)觀(guan)點，若需要(yao)原創文(wen)章可咨詢客服老師，歡迎參考。

1發病癥狀

水稻惡苗病從苗期(qi)至抽穗期(qi)均可發(fa)生。種子帶(dai)菌(jun)是引起苗期(qi)發(fa)病的(de)主因，重病種子往往不(bu)能發(fa)芽，或萌發(fa)后(hou)的(de)幼

苗不(bu)(bu)久即(ji)死(si)亡。輕病(bing)(bing)的(de)種(zhong)子(zi)(zi)長(chang)出的(de)病(bing)(bing)苗往(wang)往(wang)徒長(chang)，比健(jian)株(zhu)(zhu)高(gao)1/3，植(zhi)株(zhu)(zhu)細弱，葉片和(he)葉鞘變窄而長(chang)，全株(zhu)(zhu)呈(cheng)黃(huang)綠(lv)色(se)，根(gen)系發育不(bu)(bu)良，根(gen)毛稀少，部分病(bing)(bing)苗在(zai)插秧前、后死(si)亡。在(zai)死(si)苗上生(sheng)(sheng)有(you)(you)淡(dan)(dan)紅(hong)色(se)和(he)白(bai)色(se)霉狀(zhuang)物(wu)（即(ji)病(bing)(bing)菌的(de)分生(sheng)(sheng)孢(bao)子(zi)(zi)及分生(sheng)(sheng)孢(bao)子(zi)(zi)梗）。成株(zhu)(zhu)期一般在(zai)插秧后1個(ge)月左右出現病(bing)(bing)株(zhu)(zhu)，癥狀(zhuang)與苗期相(xiang)似。病(bing)(bing)株(zhu)(zhu)分蘗少或不(bu)(bu)分蘗，節間(jian)顯著伸長(chang)，節部常(chang)彎(wan)曲露出葉鞘之外，下(xia)(xia)部幾個(ge)莖(jing)(jing)節生(sheng)(sheng)有(you)(you)許多(duo)倒生(sheng)(sheng)的(de)不(bu)(bu)定(ding)根(gen)。剝(bo)開病(bing)(bing)莖(jing)(jing)，有(you)(you)時可見節的(de)上下(xia)(xia)組織呈(cheng)褐色(se)，莖(jing)(jing)上有(you)(you)暗褐色(se)條斑，可見白(bai)色(se)蛛絲(si)狀(zhuang)菌絲(si)體，莖(jing)(jing)稈逐漸腐朽。重病(bing)(bing)株(zhu)(zhu)多(duo)在(zai)孕穗(sui)期枯(ku)死(si)，輕病(bing)(bing)株(zhu)(zhu)常(chang)提早抽穗(sui)，穗(sui)形(xing)短小或籽(zi)粒不(bu)(bu)實。天(tian)氣潮(chao)濕時，在(zai)枯(ku)死(si)病(bing)(bing)株(zhu)(zhu)的(de)表面長(chang)滿(man)淡(dan)(dan)紅(hong)色(se)和(he)白(bai)色(se)霉狀(zhuang)物(wu)。

2病原

稱串珠(zhu)鐮(lian)孢(bao)，屬半知菌(jun)亞門(men)真菌(jun)。分(fen)生(sheng)孢(bao)子(zi)(zi)(zi)有(you)大(da)小(xiao)2種，小(xiao)分(fen)生(sheng)孢(bao)子(zi)(zi)(zi)囊(nang)卵形(xing)(xing)或(huo)(huo)扁(bian)橢(tuo)圓形(xing)(xing)，無(wu)色(se)單胞(bao)，呈鏈狀著生(sheng)，大(da)小(xiao)為（4～6）μm×（2～5）μm。大(da)分(fen)生(sheng)孢(bao)子(zi)(zi)(zi)多為紡(fang)錘形(xing)(xing)或(huo)(huo)鐮(lian)刀形(xing)(xing)，頂(ding)端較鈍(dun)或(huo)(huo)粗細均勻(yun)，具3～5個(ge)(ge)隔膜(mo)，大(da)小(xiao)（17.0～18.0）μm×（2.5～4.5）μm，多數孢(bao)子(zi)(zi)(zi)聚(ju)集時呈淡紅色(se)，干燥時呈粉紅或(huo)(huo)白色(se)。有(you)性(xing)態稱藤倉赤霉，屬子(zi)(zi)(zi)囊(nang)菌(jun)亞門(men)真菌(jun)。子(zi)(zi)(zi)囊(nang)殼藍黑色(se)球形(xing)(xing)，表面粗糙(cao)，大(da)小(xiao)（240～360）μm×（220～420）μm。子(zi)(zi)(zi)囊(nang)圓筒形(xing)(xing)，基部細而上部圓，內(nei)生(sheng)子(zi)(zi)(zi)囊(nang)孢(bao)子(zi)(zi)(zi)4～8個(ge)(ge)，排成1～2行，子(zi)(zi)(zi)囊(nang)孢(bao)子(zi)(zi)(zi)雙(shuang)胞(bao)無(wu)色(se)，長(chang)橢(tuo)圓形(xing)(xing)，分(fen)隔處(chu)稍縊縮，大(da)小(xiao)（5.5～11.5）μm×（2.5～4.5）μm。病(bing)菌(jun)能產(chan)生(sheng)赤霉素，所以能引(yin)起稻株徒(tu)長(chang)和節上產(chan)生(sheng)不定根(gen)。

3發病條件

帶菌種(zhong)子(zi)和病(bing)(bing)(bing)(bing)稻草是該病(bing)(bing)(bing)(bing)發(fa)(fa)生的初(chu)侵(qin)染源。脫谷時(shi)，由于(yu)脫谷機(ji)空隙小，轉數過快，可增加(jia)種(zhong)子(zi)受傷(shang)幾率，如播種(zhong)這(zhe)類受傷(shang)種(zhong)子(zi)比未受傷(shang)的種(zhong)子(zi)發(fa)(fa)病(bing)(bing)(bing)(bing)重(zhong)。脫粒時(shi)與(yu)病(bing)(bing)(bing)(bing)種(zhong)子(zi)混收，也會使健種(zhong)子(zi)帶菌。土(tu)溫30～50℃時(shi)易發(fa)(fa)病(bing)(bing)(bing)(bing)，傷(shang)口有利于(yu)病(bing)(bing)(bing)(bing)菌侵(qin)入(ru)；旱育(yu)(yu)秧較(jiao)水育(yu)(yu)秧發(fa)(fa)病(bing)(bing)(bing)(bing)重(zhong)；增施氮肥刺激病(bing)(bing)(bing)(bing)害發(fa)(fa)展；施用(yong)未腐熟有機(ji)肥發(fa)(fa)病(bing)(bing)(bing)(bing)重(zhong)；一(yi)般秈稻較(jiao)粳稻發(fa)(fa)病(bing)(bing)(bing)(bing)重(zhong)；糯稻發(fa)(fa)病(bing)(bing)(bing)(bing)輕；晚稻發(fa)(fa)病(bing)(bing)(bing)(bing)重(zhong)于(yu)早稻。育(yu)(yu)苗床灌水不及時(shi)，缺水受旱，發(fa)(fa)生龜裂，易使幼苗根部受傷(shang)，或(huo)拔苗時(shi)由于(yu)育(yu)(yu)苗床上缺水使根部受傷(shang)，這(zhe)類幼苗插秧后發(fa)(fa)病(bing)(bing)(bing)(bing)重(zhong)。藥劑浸種(zhong)不徹(che)底(di)的病(bing)(bing)(bing)(bing)種(zhong)子(zi)比浸種(zhong)消毒徹(che)底(di)的種(zhong)子(zi)發(fa)(fa)病(bing)(bing)(bing)(bing)重(zhong)。

4侵染循環途徑

病(bing)(bing)(bing)菌(jun)主要(yao)以(yi)菌(jun)絲體潛伏在(zai)種(zhong)子(zi)內或(huo)(huo)以(yi)分(fen)(fen)(fen)生(sheng)孢(bao)子(zi)附著在(zai)種(zhong)子(zi)表面越(yue)冬。病(bing)(bing)(bing)株上的分(fen)(fen)(fen)生(sheng)孢(bao)子(zi)和菌(jun)絲體亦(yi)有越(yue)冬能力(li)，但不是主要(yao)的初(chu)侵(qin)染來源。病(bing)(bing)(bing)種(zhong)子(zi)播(bo)(bo)種(zhong)后，幼(you)苗就會(hui)感病(bing)(bing)(bing)，重者幼(you)苗枯死。健康種(zhong)子(zi)播(bo)(bo)種(zhong)發芽(ya)后，也可由于(yu)分(fen)(fen)(fen)生(sheng)孢(bao)子(zi)萌發從芽(ya)鞘(qiao)侵(qin)入(ru)而引起(qi)幼(you)苗發病(bing)(bing)(bing)，導致徒長等。一般病(bing)(bing)(bing)株中菌(jun)絲體會(hui)蔓(man)延到(dao)全株，但不能擴展到(dao)穗部。感病(bing)(bing)(bing)或(huo)(huo)枯死的病(bing)(bing)(bing)株表面產生(sheng)分(fen)(fen)(fen)生(sheng)孢(bao)子(zi)，可借風、雨傳播(bo)(bo)而引起(qi)再侵(qin)染。在(zai)水稻開花時(shi)(shi)，分(fen)(fen)(fen)生(sheng)孢(bao)子(zi)侵(qin)染花器，造成秕谷或(huo)(huo)畸形(xing)，侵(qin)入(ru)穎或(huo)(huo)種(zhong)皮組織內，而使種(zhong)子(zi)帶菌(jun)。脫谷時(shi)(shi)，病(bing)(bing)(bing)部的分(fen)(fen)(fen)生(sheng)孢(bao)子(zi)也會(hui)飄落粘附于(yu)種(zhong)子(zi)上，病(bing)(bing)(bing)菌(jun)便在(zai)種(zhong)子(zi)表面越(yue)冬。

5防治方法

一是(shi)(shi)選育無(wu)病(bing)種(zhong)(zhong)(zhong)(zhong)子(zi)。建立無(wu)病(bing)留(liu)種(zhong)(zhong)(zhong)(zhong)田(tian)(tian)(tian)，選栽抗病(bing)品種(zhong)(zhong)(zhong)(zhong)，并進行種(zhong)(zhong)(zhong)(zhong)子(zi)消毒處理(li)。留(liu)種(zhong)(zhong)(zhong)(zhong)田(tian)(tian)(tian)及附近一般生(sheng)產田(tian)(tian)(tian)，發現病(bing)菌或(huo)病(bing)株(zhu)(zhu)應及時(shi)(shi)(shi)拔(ba)除，以防(fang)傳播(bo)蔓(man)延。留(liu)種(zhong)(zhong)(zhong)(zhong)田(tian)(tian)(tian)應單收(shou)、單打、單貯。二(er)是(shi)(shi)加(jia)強栽培管理(li)。催芽(ya)不(bu)宜過(guo)長，拔(ba)秧(yang)要(yao)盡可(ke)(ke)能避免(mian)(mian)損(sun)根(gen)。做到“五不(bu)插”：即不(bu)插隔夜秧(yang)，不(bu)插老齡秧(yang)，不(bu)插深泥(ni)秧(yang)，不(bu)插烈日秧(yang)，不(bu)插冷(leng)水浸(jin)(jin)的秧(yang)。三是(shi)(shi)清除病(bing)株(zhu)(zhu)殘體。及時(shi)(shi)(shi)拔(ba)除病(bing)株(zhu)(zhu)并銷毀，病(bing)稻(dao)(dao)草收(shou)獲后(hou)作燃料或(huo)漚制(zhi)堆肥。四是(shi)(shi)減少受傷(shang)(shang)。如(ru)育苗期要(yao)防(fang)止缺(que)水受旱，損(sun)傷(shang)(shang)稻(dao)(dao)根(gen)；拔(ba)秧(yang)前要(yao)先灌水濕(shi)潤(run)，以防(fang)損(sun)傷(shang)(shang)秧(yang)苗根(gen)部；脫(tuo)谷時(shi)(shi)(shi)要(yao)注意脫(tuo)谷機間隙不(bu)宜過(guo)小，轉速不(bu)宜過(guo)快，以免(mian)(mian)種(zhong)(zhong)(zhong)(zhong)子(zi)穎殼受傷(shang)(shang)，以減輕病(bing)情。五是(shi)(shi)種(zhong)(zhong)(zhong)(zhong)子(zi)處理(li)。用(yong)(yong)1%石灰水澄清液(ye)浸(jin)(jin)種(zhong)(zhong)(zhong)(zhong)，15～20℃時(shi)(shi)(shi)浸(jin)(jin)3d，25℃浸(jin)(jin)2d，水層要(yao)高出(chu)種(zhong)(zhong)(zhong)(zhong)子(zi)10～15cm，避免(mian)(mian)直射光；或(huo)用(yong)(yong)2%福爾(er)馬林浸(jin)(jin)悶(men)種(zhong)(zhong)(zhong)(zhong)3h，氣(qi)溫高于(yu)20℃用(yong)(yong)悶(men)種(zhong)(zhong)(zhong)(zhong)法，低于(yu)20℃用(yong)(yong)浸(jin)(jin)種(zhong)(zhong)(zhong)(zhong)法。用(yong)(yong)40%拌(ban)種(zhong)(zhong)(zhong)(zhong)雙可(ke)(ke)濕(shi)性粉劑(ji)(ji)(ji)(ji)100g或(huo)50%多菌靈(ling)可(ke)(ke)濕(shi)性粉劑(ji)(ji)(ji)(ji)150～200g，加(jia)少量水溶解(jie)后(hou)拌(ban)稻(dao)(dao)種(zhong)(zhong)(zhong)(zhong)50kg；或(huo)用(yong)(yong)50%甲基(ji)硫菌靈(ling)可(ke)(ke)濕(shi)性粉劑(ji)(ji)(ji)(ji)1000倍(bei)(bei)液(ye)浸(jin)(jin)種(zhong)(zhong)(zhong)(zhong)2～3d，翻種(zhong)(zhong)(zhong)(zhong)子(zi)2～3次/d；或(huo)用(yong)(yong)輝(hui)豐百(bai)克2mL對水5～6L，浸(jin)(jin)稻(dao)(dao)種(zhong)(zhong)(zhong)(zhong)3～5kg浸(jin)(jin)72h；或(huo)用(yong)(yong)35%惡霉(mei)靈(ling)膠懸劑(ji)(ji)(ji)(ji)200～250倍(bei)(bei)液(ye)浸(jin)(jin)種(zhong)(zhong)(zhong)(zhong)，種(zhong)(zhong)(zhong)(zhong)子(zi)量與藥(yao)液(ye)比為1∶1.5～2.0，溫度(du)16～18℃浸(jin)(jin)種(zhong)(zhong)(zhong)(zhong)3～5d，早晚(wan)(wan)各攪拌(ban)1次，浸(jin)(jin)種(zhong)(zhong)(zhong)(zhong)后(hou)帶藥(yao)直播(bo)或(huo)催芽(ya)；或(huo)用(yong)(yong)20%凈種(zhong)(zhong)(zhong)(zhong)靈(ling)可(ke)(ke)濕(shi)性粉劑(ji)(ji)(ji)(ji)200～400倍(bei)(bei)液(ye)浸(jin)(jin)種(zhong)(zhong)(zhong)(zhong)24h；或(huo)用(yong)(yong)25%施保克乳油3000倍(bei)(bei)液(ye)浸(jin)(jin)種(zhong)(zhong)(zhong)(zhong)72h；也可(ke)(ke)用(yong)(yong)80%強氯精300倍(bei)(bei)液(ye)浸(jin)(jin)種(zhong)(zhong)(zhong)(zhong)，早稻(dao)(dao)浸(jin)(jin)24h，晚(wan)(wan)稻(dao)(dao)浸(jin)(jin)12h，再用(yong)(yong)清水浸(jin)(jin)種(zhong)(zhong)(zhong)(zhong)，防(fang)效98%。必要(yao)時(shi)(shi)(shi)可(ke)(ke)在秧(yang)田(tian)(tian)(tian)噴灑95%綠(lv)亨(heng)1號（惡霉(mei)靈(ling)）精品4000倍(bei)(bei)液(ye)。