如ru黃huang瓜gua霜shuang黴mei病bing在zai溫wen室shi裏li的de病bing斑ban就jiu要yao比bi露lu地di條tiao件jian下xia大da，因yin為wei不bu易yi克ke服fu的de高gao溫wen環huan境jing，常chang為wei多duo種zhong病bing的de發fa生sheng提ti供gong條tiao件jian。因yin此ci，這zhe種zhong條tiao件jian下xia病bing原yuan菌jun可ke以yi侵qin染ran到dao葉ye脈mai上shang。在zai低di溫wen下xia，黃huang瓜gua炭tan疽ju病bing在zai葉ye片pian上shang也ye失shi去qu了le邊bian緣yuan比bi較jiao明ming顯xian的de近jin圓yuan形xing、huanghesebingbanzheyidianxingzhengzhuang，erbianchenglebianjiebuqingdehuibaisetuilvjinrunzhuangwuban。youguanwenshidapengtiaojianxiabutongbinghaidezhengzhuangbiaoxian
，youshiyinweipengneiwenshidudeyuanyinzaochengzhenduanshangdewucha，geigezhongbinghaidefangzhidailaiyidingdenandu。

2、條tiao件jian適shi宜yi
，多duo種zhong侵qin染ran病bing害hai混hun合he發fa生sheng。溫wen室shi大da棚peng常chang可ke見jian到dao在zai溫wen室shi大da棚peng裏li多duo種zhong病bing害hai同tong時shi發fa生sheng，特te別bie是shi一yi些xie症zheng狀zhuang比bi較jiao接jie近jin的de病bing害hai混hun合he發fa生sheng，無wu疑yi要yao給gei識shi別bie帶dai來lai困kun難nan。

例如在低溫寡照時期，日光溫室裏黃瓜可能在多種細菌性病害發生的同時，也會混有霜黴病、炭疽病、yibinghehuimeibingdengqinranbinghaidefasheng，eryouxiebinghaidezhengzhuangfeichangjiejin，liruchuxianzaizhizhuyepianshangdebingban
，youkenengshishuangmeibinghexijunxingjiaobanbingtongshifashengerzaochengde
，yinweizheliangzhongbinghaifashengdeshijihefashengtiaojianchabuduo
，zaitedingdeqingkuangxia，hennanshibiebingjishiyufang。

3、非侵染病害發生的頻繁，常會給人造成誤判。溫室大棚中
，常因光照、溫度

、水分

、空氣、土壤和營養、用(yong)藥(yao)以(yi)及(ji)栽(zai)培(pei)管(guan)理(li)的(de)不(bu)當(dang)引(yin)起(qi)植(zhi)株(zhu)生(sheng)育(yu)異(yi)常(chang)的(de)生(sheng)理(li)病(bing)害(hai)
，特(te)別(bie)是(shi)在(zai)低(di)溫(wen)寡(gua)照(zhao)階(jie)段(duan)，生(sheng)理(li)病(bing)害(hai)又(you)常(chang)常(chang)比(bi)侵(qin)染(ran)性(xing)病(bing)害(hai)發(fa)生(sheng)的(de)普(pu)遍(bian)和(he)頻(pin)繁(fan)。生(sheng)理(li)性(xing)病(bing)害(hai)還(hai)經(jing)常(chang)與(yu)侵(qin)染(ran)性(xing)病(bing)害(hai)交(jiao)混(hun)發(fa)生(sheng)，如(ru)植(zhi)株(zhu)葉(ye)片(pian)發(fa)黃(huang)，就(jiu)有(you)可(ke)能(neng)是(shi)很(hen)多(duo)原(yuan)因(yin)，有(you)可(ke)能(neng)是(shi)病(bing)害(hai)，也(ye)有(you)可(ke)能(neng)是(shi)缺(que)素(su)症(zheng)，還(hai)有(you)可(ke)能(neng)是(shi)因(yin)為(wei)地(di)溫(wen)低(di)而(er)造(zao)成(cheng)的(de)根(gen)係(xi)發(fa)育(yu)不(bu)良(liang)造(zao)成(cheng)的(de)，讓(rang)人(ren)很(hen)難(nan)在(zai)短(duan)時(shi)間(jian)內(nei)做(zuo)出(chu)正(zheng)確(que)判(pan)斷(duan)。

4、新的病害不斷地出現，診斷時缺乏經驗和有效資料。在溫室大棚中
，過去較少引起人們注意的一些次要病害，可能由於品種、huanjinghezaipeijishudegaibianerxunsufazhanchengweizhudaobinghai
，erqiexindebinghaiyezaibuduandichuxian。jingchangyoucainongfanying，xianzaidapengzhongdebinghaizaizengduo，haihennanzhiyu。wangwangkanzheshizhezhongbinghai
，danshizaiyongyaoyihoujiushimeiyouxiaoguo
；這(zhe)就(jiu)是(shi)因(yin)為(wei)品(pin)種(zhong)的(de)差(cha)異(yi)或(huo)者(zhe)是(shi)一(yi)些(xie)菌(jun)種(zhong)變(bian)異(yi)
，由(you)次(ci)要(yao)病(bing)害(hai)上(shang)升(sheng)為(wei)主(zhu)要(yao)病(bing)害(hai)。如(ru)近(jin)期(qi)發(fa)生(sheng)較(jiao)多(duo)的(de)褐(he)斑(ban)病(bing)，以(yi)前(qian)的(de)時(shi)候(hou)都(dou)隻(zhi)知(zhi)道(dao)是(shi)小(xiao)黃(huang)點(dian)

，不(bu)知(zhi)道(dao)是(shi)什(shen)麼(me)病(bing)害(hai)
，該(gai)怎(zen)麼(me)防(fang)治(zhi)。以(yi)為(wei)是(shi)細(xi)菌(jun)性(xing)病(bing)害(hai)，結(jie)果(guo)耽(dan)誤(wu)了(le)最(zui)佳(jia)防(fang)治(zhi)時(shi)機(ji)，造(zao)成(cheng)病(bing)害(hai)蔓(man)延(yan)。

5、renweiyinsu。zaishengchanguochengzhong，buzhuyixijie，jingchangsuiyijiadagezhongnongyaodepenshinongdu，shizhizhudezhengchangshengchangshoudaoyingxiang。liru，zaiqianduanshijian，youyuwendujiaodi，daozhihuanggualongtoubushenzhan，yixiecainongquebuwenyuanyin，lvcipenshicijishengchangdejisu，ruchimeisudengyaoji，jieguozaochengyepianzhousuo，shenzhibiaoxianchuzaoshuaizhengzhuang。