5种杀菌剂防治甜瓜霜霉病效果评价

Evaluation of Control Effects of 5 Fungicides on Muskmelon Downy Mildew

霜霉病是甜瓜的主要病害,已成为制约甜瓜生产可持续发展的重要因素之一。为避免长期单一使用同种作用机理的农药使病原菌产生抗药性,为防治霜霉病提供更多药剂选择,提高防治效果,试验选取10%四唑吡氨酯悬浮剂、687.5 g/L氟菌⋅霜霉威悬浮剂、100 g/L氰霜唑悬浮剂、20%霜脲氰悬浮剂和52.5%恶唑菌酮⋅霜脲氰水分散粒剂等5种不同作用机制的杀菌剂单剂或混剂进行甜瓜霜霉病防治对比试验。结果显示,在发病前喷药,2次药后10 d调查,10%四唑吡氨酯悬浮剂75 g⋅hm^(-2)(有效成分用量,下同)、687.5 g/L氟菌⋅霜霉威悬浮剂1032 g⋅hm^(-2)、100 g/L氰霜唑悬浮剂90 g⋅hm^(-2)、20%霜脲氰悬浮剂60 g⋅hm^(-2)和52.5%恶唑菌酮⋅霜脲氰水分散粒剂472.5 g⋅hm^(-2)对甜瓜霜霉病的防治效果分别为90.10%、89.06%、88.02%、78.13%和75.00%;3次药后10 d调查,上述药剂防治效果分别为90.79%、90.51%、89.10%、84.16%和81.24%,所有供试药剂对甜瓜霜霉病均有较好防治效果,对植株安全,生产上可作为防治甜瓜霜霉病的备选药剂,合理轮换使用。建议在发病前或发病初期进行喷施,间隔7~10 d,连续喷施2~3次。

Downy mildew is a major disease of muskmelon and has become one of the major factors restricting the sustainable development of muskmelon production.In order to avoid patho-gens become resistant to long-term-used single fungicide working under the same mechanism,pro-vide more fungicide options for downy mildew control,and improve control effects on the disease,5 single agents or mixture fungicides working under different mechanisms,namely,10%picarbutrazox SC,687.5 g/L fluopicolide-propamocarb·hydrochloride SC,100g/L cyazofamid SC,20%cymoxanil SC,52.5%famoxadone-cymoxanil WDG were selected to conduct comparative experiments on the control of muskmelon downy mildew.Results showed that,when spraying fungicides with its dos-age of active ingredient before the occurrence of the disease,the control effects of 10%picarbutra-zox·SC 75g⋅hm^(-2)(dosage of efficient component,the same below),687.5 g/L fluopicolide-propamocarb hydrochloride SC 1032 g⋅hm^(-2),100g/L cyazofamid SC 90 g⋅hm^(-2),20%cymoxanil SC 60 g⋅hm^(-2),52.5%famoxadone-cymoxanil WDG 472.5 g⋅hm^(-2) were 90.10%,89.06%,88.02%,78.13%and 75.00%respectively when surveyed at day 10 after twice spraying,and 90.79%,90.51%,89.10%,84.16%and 81.24%respectively when surveyed at 10th day after thrice spraying,all the tested fungicides had good control effects on muskmelon downy mildew and were safe for the plants,could be used as alternative fungicides to control the disease in production.Spraying fungi-cides before disease occurrence or at preliminary disease stage,with an interval of 7 to 10 days and 2 to 3 consecutive sprays,and used alternately were suggested.