威百亩对西葫芦常见土传病原菌的毒力及田间防效

为明确威百亩对西葫芦常见土传病原菌的活性及田间防治效果,以1,3-二氯丙烯为对照药剂,采用改进的密封盘法比较了2种熏蒸剂对西葫芦菌核病菌等4种病原菌的毒力及对菌核萌发的影响,并于田间采用密闭熏蒸法比较了2种药剂对西葫芦茎基腐病的防治效果.室内结果显示:威百亩对西葫芦菌核病菌、茎基腐病菌、枯萎病菌及绵腐病菌的EC₅₀分别为0.060、0.945、1.380、2.953 mg/L,而1,3-二氯丙烯对这4种病原菌的EC₅₀为516.654、928.558、633.784、77.242 mg/L,威百亩0.228 mg/L可完全抑制菌核的萌发.田间药效试验表明:威百亩150、90、75、60 kg/hm²及1,3-二氯丙烯200 kg/hm²均能不同程度控制西葫芦茎基腐病的发生,防治效果分别为88.94%、87.58%、83.76%、80.60%和64.80%,且各试验剂量均对西葫芦安全并能在一定程度上起到增产作用,威百亩150 kg/hm²处理增产率最高,达34.82%.从防治效果及经济效益分析,在西葫芦田推荐使用威百亩防治土传病害.

Toxicity and field efficacy of metham-sodium against common soil-borne pathogens of summer squash

The toxicities of the fumigants metham-sodium and 1,3-dichloropropene against Sclerotinia sclerotiorum, Fusarium oxysporum, Pythium aphanidermatum and Erwinia carotovora were detected with improved sealed plates. In order to understand the actual effects of the two fumigants, their field efficacies on E.carotovora were tested in a commercial field. Laboratory studies showed that the activity of metham-sodium to the four target pathogens was much higher than that of 1,3-dichloropropene. The EC₅₀ values of metham-sodium to S.sclerotiorum, E.carotovora, F.oxysporum and P.aphanidermatum were 0.060, 0.945, 1.380 and 2.953 mg/L, respectively. And the EC₅₀ values of 1,3-dichloropropene to the four pathogens were 516.654, 928.558, 633.784 and 77.242 mg/L, respectively. Metham-sodium completely inhibited the germination of S.sclerotiorum at 0.228 mg/L. Field trials revealed that metham-sodium applied to the field at 150, 90, 75 and 60 kg/hm² and 1,3-dichloropropene at the concentration of 200 kg/hm² could suppress E.carotovora, with a control effect of 88.94%, 87.58%, 83.76%, 80.60% and 64.80%, respectively. The marketable yields of summer squash were increased; the highest yield increase was 34.82%. Based on our results, the recommended fumigant for preventing soil-borne diseases in summer squash is metham-sodium, considering its controlling effects and economic benefits.