台灣葡萄露菌病之防治

游走胞子囊在懸浮液中於24 C經1小時釋放游走子，游走子與寄主接觸後20-60分鐘完成侵入，6小時後形成第一個吸器。接種96小時後可形成病斑，並產生游走胞子囊。測試15種殺菌劑對太病菌游走子釋放、產胞之影響，結果鋅錳乃浦抑制游走子釋放之效果最佳，其完全抑制濃度爲10 ppm，唯滅達樂及克絕則無此作用。測試10種推薦藥劑對本菌侵入葉片至產胞的影響，所有供試藥劑在本菌侵入前或侵入後及有病斑產胞者浸藥，均有防治效果，其中7種可以完全抑制産胞，侵入24小時後才浸藥，則僅80% Fosetyl-A1 W.P. , 8% Cymoxanil + 64% Mancozeb W.P.及10% Metalaxyl + 48% Mancozeb W.P.等藥劑有明顯抑制效果，侵入後96小時及120小時後施藥，則僅80% Mancozeb W.P.及10% Metalaxyl + 48% Mancozeb W.P.致果最佳，除殺死已產胞者外，經96小時觀察時能抑制再產胞。於溫室以盆栽葡萄測試80% Mancozeb W.P. 600倍、10% Metalaxyl + 48% Mancozeb W.P. 400倍及8% Cymoxanil + 64% Mancozeb W.P 750倍等三種藥劑存留在植體上有效完全抑制露菌病發生時間均不能超過2週。田間試驗，以10% Metalaxyl + 48% Mancozeb W.P. 400倍、80% Mancozeb W.P. 600倍、8% Cymoxanil + 64% Mancozeb W.P. 750倍三種藥劑輪用之防治效果較佳，約可維持一個月的保護效果。

關鍵字

葡萄露菌病；殺菌劑；防治

並列摘要

Zoospore discharge of grape downy mildew fungus, Plasmopara viticola occurred one hour after the zoosporangium suspension was incubated at 24 C in the dark. Infection was completed in 20-60 min after zoospores contacted with host leaf tissues. The first haustorium was formed 6 hr after inoculation and zoosporangial formation was observed 96 hr after inoculation. Of the 15 commercial fungicides tested for efficacy against zoospore discharge, mancozeb was the most effective with minimum inhibition concentration (MIC) at 10 ppm. The systemic fungicides, metalaxyl and cymoxanil had no effect on zoospore discharge. Efficacy of 10 commercial fungicides applied either before or after inoculation against the sporulation ability of P. viticola was determined on detached grape leaf discs. All tested fungicides was effective in inhibition of sporangial formation when applied 24 hr before inoculation But only 80% fosetyl-Al, 8% cy moxanil + 64% mancozeb, and 10% metalaxyl + 48% mancozeb completely inhibited sporangial formation when applied 24 hr after inoculation. Application at 96 hr and 120 hr after inoculation, mixtures of mancozeb with either cymoxanil or metalaxyl showed the best efficacy not only on killing sporangia but also on inhibition of sporangial reformation. The effectiveness of 80% mancozeb, 8% cymoxanil + 64% mancozeb, and 10% metalaxyl + 48% mancozeb on the potted plants reduced greatly after two weeks at the greenhouse condition In field trials, the alternative spray of 8% moxanil + 64% mancozeb, 80% mancozeb and 10% metalaxyl t 48% mancozeb gave the best control efficacy against grape downy mildew disease, and the total protective period lasted for about one month.

並列關鍵字

grape downy mildew ； fungicides ； control

國際替代計量

台灣葡萄露菌病之防治

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