4种杀菌剂对葡萄霜霉病菌的毒力及田间防效

为探明黄麻链霉菌NF0919菌株和枯草芽孢杆菌DJ-6对葡萄霜霉病的生防活性,采用叶盘法分别测定了黄麻链霉菌NF0919发酵上清液、1.0×10₁₁cfu/g枯草芽孢杆菌DJ-6 WP、代森锰锌和烯酰吗啉对葡萄霜霉病菌的室内毒力,并进行了防治葡萄霜霉病的田间试验。结果表明：NF0919菌株发酵上清液、1.0×10₁₁cfu/g枯草芽孢杆菌DJ-6 WP、代森锰锌和烯酰吗啉对葡萄霜霉病菌孢子萌发抑制的EC₅₀值分别为96.2859、86.6038、69.9472和7.2636μg/mL。NF0919菌株发酵20倍液和1.0×10₁₁cfu/g枯草芽孢杆菌DJ-6 WP1000倍液对葡萄霜霉病做预防性施药时,2次药后7d的防效分别为71.55%和70.71%,2次药后14d的防效分别为67.54%和68.19%；当做治疗性施药时,2次药后7d的防效分别为59.72%和56.07%,2次药后14d的防效分别为56.88%和57.46%。两种供试生防菌剂的防效相当,且保护效果与50%代森锰锌WP 300倍液均差异不显著,而治疗效果与40%烯酰吗啉SC 200倍液均差异显著。可见,黄麻链霉菌NF0919菌株和枯草芽孢杆菌DJ-6 WP对葡萄霜霉病具有一定的生防潜力与开发的价值。

Toxicity Test and Field Control Effect of 4 Different Fungicides on Grape Downy Mildew

To investigate the biocontrol activity of Streptomyces corchorusii strain NF0919 and Bacillus subtilis DJ-6 WP to grape downy mildew, we determined the indoor toxicity of the supernatant of S. corchorusii strain NF0919, 1.0×1011 cfu/g B. subtilis DJ-6 WP, mancozeb and dimethomorph on Plasmopara viticola by using leaf disc method, respectively, and the field control tests were conducted. The results showed that the EC 50 values of the supernatant of strain NF0919, 1.0 × 1011cfu/g B. subtilis DJ-6 WP, mancozeb and dimethomorph were 96.2859, 86.6038, 69.9472 and 7.2636 μg/mL, respectively. The values of field control effect in preventive experiments on grape downy mildew on the 7th day after 2 times spraying with 20 times liquid of the supernatant of strain NF0919 and 1000 times liquid of 1.0 × 1011cfu/g B. subtilis DJ-6 WP were 71.55%and 70.71%, and the values of field control effect on the 14th day after 2 times spraying were 67.54%and 68.19%, respectively. The values of field control effect in curative experiments on the 7th day after 2 times spraying with 20 times liquid of the supernatant of strain NF0919 and 1000 times liquid of 1.0×1011cfu/g B. subtilis DJ-6 WP were 59.72%and 56.07%, the values of field control effect on 14th day after 2 times spraying were 56.88%and 57.46%, respectively. The field control effect of the two kinds of the tested biocontrol agents was equivalent. The protective effect between each of the tested biocontrol agents and 300 times liquid of 50%mancozeb WP had no significant difference, but there were significant differences of the efficacy between each of the tested biocontrol agents and 200 times liquid of 40% dimethomorph SC. In conclusion, the S. corchorusii strain NF0919 and B. subtilis DJ-6 WP had certain biocontrol potential to grape downy mildew and value of development.