七种杀菌剂对茼蒿霜霉病的防效试验

本试验旨在筛选出防治茼蒿霜霉病的最佳药剂。病原菌试验采用组织分离纯化的方法,鉴定出病原菌为莴苣盘梗菌(Bremia lactucae. Regel)。防效试验采用含毒培养基生长速率的方法,测定七种杀菌剂对莴苣盘梗菌的防治效果,结果表明：药后72h,克菌灵EC₅₀值为1.46mg/L,毒力指数最大,对莴苣盘梗菌防治效果最显著；安克和大生EC₅₀值分别为4.31和5.63mg/L,防治效果较显著；甲霜灵的EC₅₀值为9.19mg/L,防治效果较好；普力克和杀毒矾的EC₅₀值分别为26.31mg/L和101.32mg/L,防治效果一般；优氯特EC₅₀值最大,防治效果最差。药后96h各药剂对莴苣盘梗菌的防治效果与药后72h防治效果相似。在七种杀菌剂中克菌灵对莴苣盘梗菌防效最高,防治效果最好。

Toxicity Test of Seven Fungicides on The Pathogens of Artemisia Downy Mildew

The aim of this experiment was to screen out the best bactericide for controlling Artemisia downy mildew. The pathogenic bacteria were isolated by the method of tissue identification and purification , which was identified as Bremia lactucae. Regel.The drug test used the growth rate of toxic medium to determine the inhibitory effect of seven fungicides on downy mildew. The results show: after 72h, EC₅₀ of Chlorothalonil was 1.46mg/L, the virulence index was the high, and the inhibition was most significant; EC₅₀ of dimethomorph and mancozeb were 4.31 and 5.63 mg/L, the inhibitory effects were significant; EC₅₀ of metalaxyl mancozeb was 9.19 mg/L, the inhibitory was good; EC₅₀ of propamocarb and sandofan were 26.31 and 101.32 mg/L, the inhibitory effects were common; EC₅₀ of sodium dichloroisocyanurate was the highest value, and the inhibitory was poor. The inhibitory effect was similar between 72 h and 96h.Therefore, among the seven fungicides, chlorothalonil had the best inhibitory effect.