哈(ha)密瓜根(gen)結線蟲(chong)病(bing)癥(zheng)狀主要(yao)為害(hai)根(gen)系，在(zai)主根(gen)和側根(gen)上產生許多(duo)大(da)小不等(deng)乳白色根(gen)結，剖開(kai)根(gen)結可見白色半(ban)透明梨形線蟲(chong)。發病(bing)后(hou)期病(bing)根(gen)顏色變深(shen)，最后(hou)腐(fu)爛(lan)，植(zhi)株或幼苗(miao)地上部(bu)分(fen)隨病(bing)害(hai)發展葉(xie)色變淡，由下向(xiang)上逐漸萎蔫至全部(bu)枯死(si)。

哈密(mi)瓜根結線(xian)蟲(chong)病(bing)病(bing)原MeloidogyneincognitaChitwood稱南方(fang)根結線(xian)蟲(chong)。病(bing)原線(xian)蟲(chong)雌雄(xiong)異(yi)形，幼蟲(chong)細長蠕蟲(chong)狀(zhuang)(zhuang)。雄(xiong)成蟲(chong)呈(cheng)線(xian)狀(zhuang)(zhuang)，尾端稍圓，無色透明，大小為1.0-1.5mm×0.03-0.04mm。雌成蟲(chong)呈(cheng)梨形，每(mei)頭雌線(xian)蟲(chong)可產(chan)卵300-800粒(li)，埋生于寄主組織內(nei)，大小為0.44-1.59mm×0.26-0.81mm。

哈(ha)密瓜根結線(xian)(xian)(xian)蟲(chong)(chong)(chong)(chong)病(bing)發(fa)病(bing)特點(dian)南方根結線(xian)(xian)(xian)蟲(chong)(chong)(chong)(chong)冬(dong)季可在(zai)(zai)(zai)多種(zhong)蔬菜(cai)上(shang)為害繁(fan)殖越(yue)(yue)冬(dong)。北方菜(cai)區，線(xian)(xian)(xian)蟲(chong)(chong)(chong)(chong)主要(yao)以雌成(cheng)蟲(chong)(chong)(chong)(chong)在(zai)(zai)(zai)根結內(nei)(nei)(nei)排(pai)出的卵(luan)(luan)(luan)囊(nang)團隨(sui)病(bing)殘體在(zai)(zai)(zai)保護(hu)地(di)土(tu)壤中(zhong)越(yue)(yue)冬(dong)。溫度(du)(du)回升，越(yue)(yue)冬(dong)卵(luan)(luan)(luan)孵(fu)化(hua)成(cheng)幼蟲(chong)(chong)(chong)(chong)，或(huo)部分越(yue)(yue)冬(dong)幼蟲(chong)(chong)(chong)(chong)繼續發(fa)育(yu)在(zai)(zai)(zai)土(tu)壤表層內(nei)(nei)(nei)活(huo)動。遇(yu)到寄(ji)主便從幼根侵(qin)(qin)入，刺激寄(ji)主細胞(bao)分裂(lie)增生(sheng)形(xing)成(cheng)巨細胞(bao)，過度(du)(du)分裂(lie)形(xing)成(cheng)瘤狀根結。幼蟲(chong)(chong)(chong)(chong)在(zai)(zai)(zai)根結內(nei)(nei)(nei)發(fa)育(yu)為成(cheng)蟲(chong)(chong)(chong)(chong)，并開始交(jiao)尾產(chan)卵(luan)(luan)(luan)。卵(luan)(luan)(luan)在(zai)(zai)(zai)根結內(nei)(nei)(nei)孵(fu)化(hua)，1齡幼蟲(chong)(chong)(chong)(chong)留(liu)在(zai)(zai)(zai)卵(luan)(luan)(luan)內(nei)(nei)(nei)，2齡幼蟲(chong)(chong)(chong)(chong)鉆出寄(ji)主進行(xing)再侵(qin)(qin)染。主要(yao)通(tong)過病(bing)土(tu)、病(bing)苗、澆水(shui)和農具等(deng)傳播(bo)。土(tu)溫20-30℃，濕(shi)度(du)(du)40%-70%條件下線(xian)(xian)(xian)蟲(chong)(chong)(chong)(chong)繁(fan)殖很快，容易(yi)在(zai)(zai)(zai)土(tu)內(nei)(nei)(nei)大(da)量(liang)積累。一(yi)般地(di)勢高躁、土(tu)質疏松，及缺(que)水(shui)缺(que)肥的地(di)塊或(huo)棚室發(fa)生(sheng)較(jiao)重(zhong)，通(tong)常溫室重(zhong)于大(da)棚，大(da)棚又(you)重(zhong)于露(lu)地(di)。此外(wai)，重(zhong)茬種(zhong)植(zhi)發(fa)病(bing)較(jiao)重(zhong)。

哈密瓜根結線蟲病的防治方法

（1）農業防治。

無病(bing)土育(yu)苗(miao)，病(bing)害常(chang)發區選用(yong)無蟲(chong)土或大田土育(yu)苗(miao)，施用(yong)不帶病(bing)殘(can)體或充分(fen)腐熟(shu)的有機肥，也可用(yong)基質育(yu)苗(miao)，同時注意防止人為傳播。

重病(bing)地塊收(shou)獲后(hou)(hou)(hou)應(ying)徹底清(qing)除病(bing)根殘體，深翻(fan)土壤30-50cm，在(zai)春末夏初進行日光(guang)高(gao)溫消毒滅蟲。即在(zai)前茬拉秧后(hou)(hou)(hou)分別施生石灰和碎(sui)稻草4.5-7.5t/hm2翻(fan)耕混勻后(hou)(hou)(hou)挖溝起壟或作畦，灌滿水后(hou)(hou)(hou)蓋好地膜并壓實，再密閉棚室10-15天，可將土中線蟲及病(bing)菌、雜草等全(quan)部殺滅。處理(li)后(hou)(hou)(hou)注意增施生物菌肥。

（2）藥劑防治。

在播種(zhong)或(huo)定(ding)(ding)(ding)植(zhi)(zhi)前根據藥劑性(xing)質(zhi)進(jin)行土(tu)壤處理，可選用1.8%蟲螨克乳(ru)油乳(ru)油10-15L/hm2對水均勻(yun)施(shi)(shi)與(yu)苗床，或(huo)施(shi)(shi)與(yu)定(ding)(ding)(ding)植(zhi)(zhi)溝或(huo)定(ding)(ding)(ding)植(zhi)(zhi)穴再播種(zhong)或(huo)定(ding)(ding)(ding)植(zhi)(zhi)。還可用98%-100%必速滅微粒劑75-120kg/hm2，均勻(yun)撒施(shi)(shi)或(huo)溝施(shi)(shi)于20cm表層土(tu)內(nei)(nei)，施(shi)(shi)藥后立(li)即覆(fu)土(tu)、灑水封閉或(huo)蓋膜(mo)7-12天后，松土(tu)放(fang)氣(qi)3-10天，再播種(zhong)或(huo)定(ding)(ding)(ding)植(zhi)(zhi)。亦可用22.5-30kg/hm2的3%米樂(le)爾顆粒劑均勻(yun)施(shi)(shi)與(yu)定(ding)(ding)(ding)植(zhi)(zhi)溝穴內(nei)(nei)。

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