土壤环境条件对威百亩熏蒸防治黄瓜枯萎病的影响

Effects of soil environment on the metam sodium fumigation against cucumber Fusarium wilt

为探究威百亩在不同土壤环境条件下的消毒效果,采用离体和活体方法研究施药量、覆膜熏蒸时间、土壤相对含水量及土壤温度对威百亩熏蒸防治黄瓜枯萎病的作用效果。结果表明,25℃条件下,威百亩12 mg(a.i.)/kg土壤熏蒸消毒,对尖孢镰刀菌Fusarium oxysporum的抑制率为78.82%,对黄瓜枯萎病的防治效果为87.03%,且对作物安全无药害;威百亩对尖孢镰刀菌的熏蒸抑制作用随着熏蒸时间的增加而增强,土壤熏蒸10 d后对尖孢镰刀菌的抑制率为95.21%;土壤相对含水量为30%和50%时,威百亩对黄瓜枯萎病的防治效果分别为72.32%和82.14%,含水量过高或过低均不利于药效的发挥,而且还会对作物产生药害反应。威百亩的熏蒸效果随着土壤温度的升高而增强,在25、30、35℃时对黄瓜枯萎病的防治效果分别为80.18%、98.20%和100.00%。表明威百亩结合日光消毒温度大于25℃、土壤相对含水量为30%或50%、熏蒸10~15 d可有效控制土壤中尖孢镰刀菌引起的黄瓜枯萎病。

In order to investigate the effects of metam sodium inhibition in cucumber Fusarium wilt brought by the dosages of metam sodium, fumigation time, soil relative water content and soil temperature,the vitro and vivo trials were conducted in this study. The results showed that metam sodium at 12 mg（ a. i.） / kg could effectively inhibit the growth of Fusarium oxysporum with the inhibition of78. 82%,meanwhile,the control effect of metam sodium against cucumber Fusarium wilt was 87. 03%with no phytotoxicity under the condition of 25℃. The inhibition was enhanced along with the increasing of soil temperature. After ten days of fumigation,the inhibition reached up to 95. 21%. The efficacy of metam sodium against cucumber Fusarium wilt reached up to 72. 32% and 82. 14% respectively at the condition of soil relative water content on 30% and 50%. The soil water content was too high or too low to exert the efficacy of metam sodium,and also phytotoxicity reaction appeared on cucumber seedlings.The activity of metam sodium was largely influenced by the temperature and it would be enhanced with soil temperature rising. The efficacy of metam sodium against cucumber Fusarium wilt reached up to80. 18%,98. 20% and 100. 00% respectively, at 25, 30 and 35℃. In conclusion, with soil temperature above 25℃,soil relative water content 30% or 50%,fumigation period 10- 15 d,metamsodium combined with solarization could effectively control cucumber Fusarium wilt caused by F.oxysporum.