暴雨、洪災在長江流域和東北地區肆虐,對我國農作物生產帶來嚴重影響。近日,在山東、河南、河(he)北(bei)為(wei)玉(yu)米(mi)主(zhu)要(yao)的(de)夏(xia)播(bo)作(zuo)物(wu)區(qu),出(chu)現(xian)曆(li)史(shi)罕(han)見(jian)的(de)高(gao)溫(wen)高(gao)濕(shi)氣(qi)候(hou),這(zhe)種(zhong)異(yi)常(chang)天(tian)氣(qi)給(gei)夏(xia)玉(yu)米(mi)生(sheng)產(chan)帶(dai)來(lai)一(yi)些(xie)疑(yi)難(nan)的(de)問(wen)題(ti)。目(mu)前(qian),夏(xia)玉(yu)米(mi)生(sheng)長(chang)大(da)多(duo)處(chu)於(yu)大(da)喇(la)叭(ba)口(kou)至(zhi)抽(chou)雄(xiong)前(qian)期(qi),各(ge)地(di)已(yi)陸(lu)續(xu)發(fa)生(sheng)一(yi)些(xie)病(bing)害(hai)和(he)生(sheng)長(chang)異(yi)常(chang)問(wen)題(ti),而(er)這(zhe)些(xie)異(yi)常(chang)對(dui)未(wei)來(lai)玉(yu)米(mi)生(sheng)產(chan)有(you)何(he)影(ying)響(xiang)?農(nong)民(min)應(ying)該(gai)采(cai)取(qu)哪(na)些(xie)有(you)效(xiao)措(cuo)施(shi)進(jin)行(xing)防(fang)控(kong)?就(jiu)此(ci),記(ji)者(zhe)走(zou)訪(fang)了(le)國(guo)家(jia)現(xian)代(dai)玉(yu)米(mi)產(chan)業(ye)技(ji)術(shu)體(ti)係(xi)的(de)植(zhi)保(bao)崗(gang)位(wei)專(zhuan)家(jia)。
玉米頂腐病大麵積發生
崗(gang)位(wei)專(zhuan)家(jia)向(xiang)記(ji)者(zhe)介(jie)紹(shao)說(shuo),當(dang)前(qian)夏(xia)玉(yu)米(mi)生(sheng)產(chan)中(zhong)存(cun)在(zai)的(de)問(wen)題(ti)有(you),一(yi)是(shi)各(ge)地(di)普(pu)遍(bian)發(fa)生(sheng)了(le)細(xi)菌(jun)性(xing)頂(ding)腐(fu)病(bing),二(er)是(shi)許(xu)多(duo)地(di)方(fang)出(chu)現(xian)玉(yu)米(mi)葉(ye)片(pian)扭(niu)曲(qu)現(xian)象(xiang)。由(you)於(yu)這(zhe)兩(liang)類(lei)生(sheng)產(chan)問(wen)題(ti)以(yi)往(wang)很(hen)少(shao)發(fa)生(sheng),農(nong)民(min)和(he)基(ji)層(ceng)技(ji)術(shu)人(ren)員(yuan)認(ren)識(shi)不(bu)夠(gou),也(ye)不(bu)了(le)解(jie)誘(you)發(fa)的(de)原(yuan)因(yin),無(wu)法(fa)采(cai)取(qu)有(you)效(xiao)的(de)應(ying)對(dui)措(cuo)施(shi),如(ru)果(guo)措(cuo)施(shi)不(bu)當(dang)還(hai)會(hui)影(ying)響(xiang)玉(yu)米(mi)產(chan)量(liang),增(zeng)加(jia)生(sheng)產(chan)成(cheng)本(ben)。
根據玉米產業體係植保專家和相關試驗站的調查,7月下旬以來玉米細菌性頂腐病在夏玉米區廣泛發生,如河南新鄉市、焦作市,山東淄博市、聊城市,河北衡水市、邯鄲市、邢台市等地均有發生,個別嚴重地塊玉米病株率達到50%以上。發生頂腐病玉米的葉片從喇叭口伸出後可以見到葉尖腐爛,腐爛部位逐漸向下擴展;嚴重發病植株的發病葉片腐爛部位粘連並緊包在一起,雄穗無法正常抽出並被細菌侵染發生腐爛;如果病害發生早,上部葉片會因腐爛而緊貼莖稈,無法伸展,無雌穗;腐爛的葉片有明顯的臭味。
是什麼原因造成今年夏玉米生產中大麵積發生細菌性頂腐病呢?專家告訴記者說,誘發這種病害的原因很多,主要有以下兩方麵原因:一(yi)是(shi)高(gao)溫(wen)氣(qi)候(hou)條(tiao)件(jian)。玉(yu)米(mi)喇(la)叭(ba)口(kou)期(qi)遇(yu)到(dao)持(chi)續(xu)高(gao)溫(wen)易(yi)發(fa)生(sheng)頂(ding)腐(fu)病(bing)。由(you)於(yu)高(gao)溫(wen)和(he)強(qiang)光(guang)照(zhao),造(zao)成(cheng)玉(yu)米(mi)喇(la)叭(ba)口(kou)內(nei)夜(ye)間(jian)形(xing)成(cheng)的(de)吐(tu)水(shui)溫(wen)度(du)升(sheng)高(gao),傷(shang)害(hai)葉(ye)片(pian)的(de)幼(you)嫩(nen)組(zu)織(zhi),形(xing)成(cheng)細(xi)菌(jun)入(ru)侵(qin)的(de)傷(shang)口(kou);meitianyumizhouqixingdetushuihegaowenqihou,jiasuxijundaliangfanzhi,liyuxijunxingbinghaidefasheng,shutianneijiunenggoushiyepiandeyounenzuzhidaliangfulan。ershipinzhongdeminganxing。butongyumipinzhongdikanggaowendenenglihekangbingnenglicunzaichayi,zhengdan958等屬於較敏感的品種,因此發病嚴重。
專家支招防治頂腐病
麵對大範圍發生的頂腐病,該如何控製呢?專家說,解決的方法有:一是及時噴藥進行防治。細菌性頂腐病如果早發現、早(zao)施(shi)藥(yao),就(jiu)有(you)較(jiao)好(hao)的(de)控(kong)製(zhi)效(xiao)果(guo)。因(yin)此(ci),發(fa)現(xian)病(bing)害(hai)後(hou)要(yao)立(li)即(ji)噴(pen)施(shi)農(nong)用(yong)鏈(lian)黴(mei)素(su)或(huo)菌(jun)毒(du)清(qing)等(deng)藥(yao)劑(ji)予(yu)以(yi)控(kong)製(zhi)。但(dan)一(yi)般(ban)情(qing)況(kuang)下(xia),當(dang)在(zai)田(tian)間(jian)看(kan)到(dao)明(ming)顯(xian)發(fa)病(bing)植(zhi)株(zhu)時(shi),病(bing)害(hai)已(yi)進(jin)入(ru)嚴(yan)重(zhong)發(fa)生(sheng)階(jie)段(duan)。此(ci)時(shi)再(zai)用(yong)藥(yao),效(xiao)果(guo)較(jiao)差(cha)。二(er)是(shi)進(jin)行(xing)農(nong)業(ye)防(fang)治(zhi)。如(ru)果(guo)頂(ding)腐(fu)病(bing)發(fa)現(xian)較(jiao)晚(wan),葉(ye)片(pian)已(yi)嚴(yan)重(zhong)腐(fu)爛(lan)並(bing)粘(zhan)連(lian)在(zai)一(yi)起(qi),為(wei)減(jian)少(shao)病(bing)菌(jun)對(dui)雄(xiong)穗(sui)的(de)侵(qin)染(ran),應(ying)立(li)即(ji)組(zu)織(zhi)農(nong)民(min)用(yong)刀(dao)片(pian)挑(tiao)開(kai)粘(zhan)連(lian)的(de)葉(ye)片(pian)。挑(tiao)開(kai)的(de)葉(ye)片(pian)在(zai)幹(gan)燥(zao)的(de)空(kong)氣(qi)下(xia)發(fa)病(bing)組(zu)織(zhi)會(hui)很(hen)快(kuai)幹(gan)枯(ku),病(bing)害(hai)不(bu)會(hui)繼(ji)續(xu)擴(kuo)展(zhan),同(tong)時(shi)也(ye)保(bao)證(zheng)了(le)雄(xiong)穗(sui)能(neng)夠(gou)正(zheng)常(chang)抽(chou)出(chu)。
玉米心葉扭曲現象需注意
ciwai,jinlaizaixiayumiqudeyixiedifang,chuxianleyumixinyeniuquchengxianbianzhuangjixingdexianxiang。zhuanjiajieshaoshuo,yumicongchumiaodaochouxiongqian,zaibutongdeyelingjunyoukenengchuxianxinyeniuqujixing。daozhiyumixinyeniuqu、畸形的主要原因有:一是除草劑使用不當所引起。苗前除草劑(如乙草胺、異丙甲草胺等酰胺類除草劑)可引發幼葉皺縮扭曲不能完全展開,形成D型苗,植株矮化、發育畸形。苗後除草劑若在玉米5葉期後使用,或在高溫條件下噴施,或劑量過大,或玉米種衣劑、拌種劑中含有機磷農藥或玉米出苗後噴施過有機磷農藥,如毒死蜱(樂斯本)等,在噴藥後3-7天就會出現玉米心葉卷曲、葉片皺縮並有不規則黃色藥害斑,嚴重時心葉也會腐爛。對於除草劑引起的植株生長畸形,如果屬於輕度,一般多數會自然恢複正常;受害田要及時追肥並澆水,可以緩解藥害;心葉嚴重扭曲的,可采用人工剖開心葉的方法保證雄穗正常生長。二是薊馬為害可以引起心葉扭曲。玉米在3-5葉期常常受到薊馬為害,嚴重受害植株的心葉卷曲呈鞭狀、甚至不能正常抽出;薊馬為害的葉片上有點狀褪綠,剝開心葉可見大量薊馬活動。薊馬引起的心葉扭曲,可選用10%吡蟲啉可濕性粉劑或1.8%阿維菌素或25%saichongqinshuifensanjijunyunpenwu,zhongdianweixinyeheyepianbeimian。yanzhongjixingdezhizhuyinggairengongpoukainiuquxinye。sanshizaiteshuqihoutiaojianxia,yixiepinzhongyinshenglifayuyichangyinqixinyeniuqu。zhezhongyichangzhuyaochuxianzaichouxiongqian,xinyechengbianzhuangniuqu,dingduanwaixiangyice,chouxiongkunnan。ruotongyigepinzhongdamianjichuxianjixing,duoweipinzhongshengliwentisuozhi,youfadeqihouyinsuyoushengchangqianqizaoshoujiaochangqidediwengaoshi、喇叭口期發生高溫、幹(gan)旱(han)等(deng)。生(sheng)理(li)因(yin)素(su)造(zao)成(cheng)的(de)心(xin)葉(ye)扭(niu)曲(qu)一(yi)般(ban)會(hui)在(zai)較(jiao)大(da)範(fan)圍(wei)的(de)多(duo)個(ge)品(pin)種(zhong)上(shang)同(tong)時(shi)出(chu)現(xian)。扭(niu)曲(qu)嚴(yan)重(zhong)時(shi)需(xu)要(yao)用(yong)刀(dao)縱(zong)向(xiang)剖(pou)開(kai)卷(juan)曲(qu)的(de)心(xin)葉(ye),人(ren)工(gong)協(xie)助(zhu)抽(chou)雄(xiong)。
植保專家最後強調說,當前夏玉米正值一個關鍵的生長階段,加強田間管理,及時發現生產問題並采取正確、有(you)效(xiao)的(de)控(kong)製(zhi)措(cuo)施(shi),這(zhe)對(dui)於(yu)保(bao)證(zheng)秋(qiu)糧(liang)豐(feng)收(shou)至(zhi)關(guan)重(zhong)要(yao)。因(yin)此(ci),各(ge)地(di)農(nong)民(min)在(zai)發(fa)現(xian)生(sheng)產(chan)問(wen)題(ti)後(hou),要(yao)積(ji)極(ji)向(xiang)當(dang)地(di)農(nong)業(ye)技(ji)術(shu)推(tui)廣(guang)部(bu)門(men)和(he)基(ji)層(ceng)農(nong)業(ye)研(yan)究(jiu)單(dan)位(wei)及(ji)時(shi)反(fan)映(ying),通(tong)過(guo)當(dang)地(di)專(zhuan)家(jia)的(de)辨(bian)認(ren)和(he)指(zhi)導(dao),及(ji)時(shi)解(jie)決(jue)生(sheng)產(chan)問(wen)題(ti),或(huo)通(tong)過(guo)基(ji)層(ceng)單(dan)位(wei)將(jiang)一(yi)些(xie)不(bu)易(yi)辨(bian)別(bie)的(de)問(wen)題(ti)轉(zhuan)交(jiao)省(sheng)級(ji)單(dan)位(wei)和(he)國(guo)家(jia)相(xiang)關(guan)產(chan)業(ye)體(ti)係(xi)的(de)有(you)關(guan)專(zhuan)家(jia),經(jing)過(guo)他(ta)們(men)科(ke)學(xue)鑒(jian)定(ding),為(wei)農(nong)民(min)提(ti)供(gong)解(jie)決(jue)問(wen)題(ti)的(de)可(ke)行(xing)方(fang)法(fa)。
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