30亿CFU/g芽胞杆菌可湿性粉剂的研制及其对马铃薯黄萎病和疮痂病的防治效果

黄萎病和疮痂病是马铃薯生产上的重要土传病害，严重影响马铃薯的产量与品质，但缺乏有效的防治药剂。本研究以枯草芽胞杆菌HMB26553和解淀粉芽胞杆菌PHODG36为有效成分，通过对润湿剂、分散剂及紫外保护剂的筛选，确定了30亿CFU/g芽胞杆菌可湿性粉剂的配方(质量分数):HMB26553菌株母药10%、PHODG36菌株母药10%、润湿剂LT-569 1%、分散剂MF 2%、紫外保护剂抗坏血酸1%和滑石粉76%。该制剂芽胞数量37.6亿 CFU/g，杂菌率2.8%，pH 7.8，细度98.2%，干燥减量1.6%，润湿时间95.7 s，悬浮率80.7%。温室盆栽试验结果表明:该可湿性粉剂15~45 kg/hm2拌种处理对马铃薯出苗安全，对生长无不良影响，对马铃薯黄萎病的防治效果为45.1%~47.4%。田间小区试验结果表明:该可湿性粉剂15~45 kg/hm2拌种处理能显著减轻马铃薯疮痂病的发生，其中30 kg/hm2拌种处理防治效果高达72.0%，增产率达15.5%。不同地区的田间示范试验应用结果表明:该可湿性粉剂30 kg/hm2拌种处理对马铃薯黄萎病的防治效果为50.8%~62.1%，疮痂病为63.9%~65.7%，增产率为14.3%~29.4%。本研究结果表明，30亿CFU/g芽胞杆菌可湿性粉剂能有效防治马铃薯土传病害且增产作用明显，为该制剂在马铃薯生产上应用提供了科学依据。

Development of 3 billion CFU/g Bacillus wettable powder and its control efficacy on potato Verticillium wilt and scab

Soilborne diseases such as potato Verticillium wilt and potato scab seriously affected the yield and quality of potato and no effective chemical is available to control the diseases. In this study, Bacillus subtilis HMB26553 and B. amyloliquefaciens PHODG36 were used as active ingredients to develop wettable powder (WP). After evaluating the doses of the wetting agent, dispersant, and UV protective agent, the optimal formulation of 3 billion CFU/g Bacillus WP was established as follows: 10% HMB26553 technical concentrate (TK), 10% PHODG36 TK, 1% wetting agent LT-569, 2% dispersant MF, 1% UV protective agent ascorbic acid, talc powder 76%. The spore content of the WP was up to 3.76 billion CFU/g; the rate of mixed bacteria was 2.8%; the pH value was 7.8; the fineness was 98.2%; the drying loss was 1.6%; the wetting time was 95.7 s; and the suspension rate was 80.7%. Pot experiment showed that seed-dressing with 15 to 45 kg/hm2 of the WP was safe on potato seedling emergence, and had no adverse effects on potato growth. The control effect on potato Verticillium wilt ranged from 45.1% to 47.4%. Field plot experiments demonstrated that treatments with 15 to 45 kg/hm2 of WP could significantly reduce the occurrence of potato scab, the control efficacy was 72.0% and the yield increase rate was 15.5% of treatment with 30 kg/hm2 WP. Field trial demonstrations in different regions showed that the control efficacy of potato Verticillium wilt and potato scab was 50.8% to 62.1%, and 63.9% to 65.7%, respectively, with the treatment of 30 kg/hm2 WP. Meanwhile, potato yields increased from 14.3% to 29.4%. The results indicated that 3 billion CFU/g Bacillus WP could effectively control potato soil-borne diseases, and significantly increase potato yield, providing a basis for the extensive application of WP in potato production.