北部地區洋香瓜與西瓜蔓枯病之調查與防治

Survey and Management Practices of Gummy Stem Blight on Cantaloupe and Watermelon in Northern Taiwan

葉俊巖(Chun-Yen Yeh) ； 黃義雄(Yi-Hsiung Huang)

《桃園區農業改良場研究彙報》 39期 (1999/12) Pp. 41-49

https://doi.org/10.29567/ZHWHGX.199912.0003

摘要

蔓枯病為北部地區西瓜與洋香瓜的重要病害之一，本試驗調查其田間之消長情形，篩選防治藥劑，比較種子消毒，子葉摘除以及不同施藥時期等處理對蔓枯病之防治效果。調查顯示：春作西瓜與洋香瓜苗期之發病率，分別為8－11%，及3－5%。定植40天以後田間發病明顯，七月份最嚴重，西瓜與洋香瓜之發病率分別達42%與19%。秋作僅調查洋香瓜，十月時發病率雖達46%，因正值採收期因此不再施藥。種子先催芽再浸藥30分鐘，苗蔓枯病可抑制於8%以下，不僅可縮短浸藥時間，且與直接浸藥4小時之處理無差異。藥劑篩選試驗之結果顯示，施用21.2%依滅列（lmazaIil）E.C. 0.2 kg ai/ha（kilogram active ingredient/hectare）之防治效果最好，發病率為5.3%；其次為40%護矽得（Flusilazole）E.C. 0.05 kg ai/ha之處理，發病率為22.2%均與對照之64.7%有極顯著之差異。比較不同施藥時期之結果，1996年預防性施藥與發病初期施藥均可有效防治本病害，但1997年之結果僅預防性施藥對病害具抑制效果，而發病初期才施藥則與對照處理無顯著差異。洋香瓜種子消毒配合預防性施用21.2%依滅列0.2 kg ai/ha對病害防治具協力效應；摘除子葉對蔓枯病防治則無顯著之效應。

關鍵字

蔓枯病 ； 藥劑篩選 ； 施藥時程 ； 種子消毒

並列摘要

Gummy stem blight is one of the most devastating diseases of watermelon and cantaloupe in northern Taiwan. The seasonal prevalence of the disease were surveyed, while fungicides screening and their application timing, disinfection process, and remove of cotyledon as well as combinations of these practices were also studied in the experiment. For the spring crops of 1991, the incidence of gummy stem blight on seedlings of cantaloupe and watermelon were 3-5% and 8-11 % respectively. The disease appear mainly in the field around 40 days after transplanting, and the disease incidence for cantaloupe and watermelon were 21% and 42% respectively. For the autumn crops, only cantaloupe was surveyed. The disease incidence was 46% in October, and the environment was favorable for disease development. For seed disinfecting process, there was no significant difference of disease suppression on seedlings between presoaking and after-soaking of seeds followed by fungicides dipping. Time for seed disinfection might be saved while seeds were pre-soaked .for four hours in water and followed by 30 minutes dipping in one of the fungicides. Four fungicides, 21.2% Imazalil E.C. 0.2 kg ai/ha (kilogram active ingredient/hectare); 40% Flusilazole E.C. 0.05 kg ai/ha and 0.04 kg ai/ha; 24.9% Difenconazole E.C. 0.08 kg ai/ha and 0.04 kg ai/ha and 50% Summilex-D W.P. 0.3 kg ai/ha were separately applied on cantaloupe. Incidences of the disease were 5.3%; 22.2%; 37.2%; 40.1%; 41.2% and 40.7% respectively. Effects of all treatment were significantly different against check (64.7%) by 1 % level. In 1996, effects of early application and late application of 40% Flusilazole E.C. 0.05 kg ai/ha on cantaloupe were compared. The disease incidences were 8.9% and 32%, significantly different from each other at the 1% level, as against check (58.6%). But in 1997, against the early application (24.1%) and check (65.9%), significant difference was at 1% level. The difference between early and late application (53.7%) was insignificant. On cantaloupe, while seeds were disinfected with 2000x of 21.2% Imazalil and followed by early application of Imazalil E.C. 0.2 kg ai/ha or 40% Flusilazole E.C. 0.04 kg ai/ha, the disease incidence were 3.2% and 4.8% respectively. Synergistic effect was found in this combination practice, but no such effect was found if seed disinfection was replaced by decotyledon. Based on the outcome of these study, we agreed with an eailier recommendations that gummy stem blight on cucurbits are seedborne, and suggest, seed disinfection should be followed by early application of fungicide after 30-35 days of transplant.

並列關鍵字

Gummy stem blight ； Fungicide screening ； Application timing ； Seed disinfection