枯草芽孢杆菌对棉花立枯病和黄萎病的防效评价

目的 研究施用枯草芽孢杆菌(Bacillus subtilis)对棉花立枯病和黄萎病的防效及其对产量和纤维品质的影响,为合理使用该药剂防治棉花立枯病和黄萎病提供依据。方法 采用田间试验,设置10×10 ⁸活芽孢/g、15×10 ⁸活芽孢/g和30×10 ⁸活芽孢/g 3个不同活芽孢数量的可湿性粉剂,按照药种比1∶10播前种子处理,评价不同处理对棉花立枯病和黄萎病的防效以及对产量和纤维品质的影响。 结果 3个处理均能降低立枯病的病株率、病情指数和死苗率,其中15×10 ⁸活芽孢/g处理效果最好,防效达44.31%,死苗率显著低于对照;15×10 ⁸和30×10 ⁸活芽孢/g处理对黄萎病的防治效果显著,病株率和病情指数显著低于对照,其中15×10 ⁸活芽孢/g处理防治效果高达70.71%;3个处理籽棉产量和铃重均有提高,其中15×10 ⁸和30×10 ⁸活芽孢/g处理的籽棉产量增产率分别达到20.1%和24.3%;各处理对衣分、籽指、单株铃数及纤维品质指标均没有明显影响。 结论 枯草芽孢杆菌拌种处理能减少死苗率,降低棉田立枯病、黄萎病的病株率和病情指数,提高铃重和籽棉产量,对棉花的纤维品质也无不利影响。其中以15×10 ⁸活芽孢/g处理防治病害效果最佳,能够明显提高产量,可用于防治棉花立枯病和黄萎病。

Evaluation of Control Effect by Bacillus subtilis on the Damping-off and Verticillium wilt of Cotton

【Objective】 To identify the control effects of Bacillus subtilis on cotton damping-off and Verticillium wilt, and the effects on yield and fiber quality. 【Methods】 Three wet table powders with 1 billion live spores / g, 1.5 billion live spores / g and 3 billion live spores / g were set up through the field experiment, and the seeds were treated before sowing at 1:10 according to the seed ratio. The control effects of different treatments on damping-off and Verticillium wilt as well as their effects on yield and fiber quality were evaluated. 【Results】 The three treatments could reduce the diseased plant rate, disease index and seedling mortality rate of damping-off, 1.5 billion live spores / g had the best control effect, which was 44.31%. 1.5 billion and 3 billion live spores / g treatments had significant control effects on Verticillium wilt, and the diseased plant rate and disease index were significantly lower than that of the control. Among them, the control effect of 1.5 billion live spores / g treatment was as high as 70.71%. The seed cotton yield and boll weight of the three treatments were increased, and the seed cotton yield of 1.5 billion and 3 billion live spores / g treatments increased by 20.1% and 24.3% respectively; and there was no significant effect on lint percentage, seed index, boll number per plant and fiber quality index. 【Conclusion】 Bacillus subtilis seed dressing treatment can reduce the seedling death rate, the diseased plant rate and disease index, and also increase boll weight and seed cotton yield and has no adverse effect on the fiber quality of cotton. Among them, 1.5 billion live spores per gram treatment have the most significant control effect and can significantly increase the yield, so it can be recommended.