解淀粉芽孢杆菌B9601-Y2对玉米叶斑病的防治效果

采用凹玻片法测定解淀粉芽孢杆菌B9601-Y2(Y2)发酵液、上清液和芽孢对4种病害的孢子萌发抑制率,研究Y2对玉米叶斑病的防治效果。结果表明,Y2发酵液、上清液和芽孢对大斑病菌抑制率分别为82.72%、76.71%、4.89%,对小斑病菌抑制率分别为88.04%、82.85%、5.63%,对圆斑病菌抑制率分别为84.90%、79.90%、10.81%,对弯孢霉叶斑病菌抑制率分别为98.79%、95.05%和6.23%。温室盆栽试验表明,Y2的最佳施用浓度为1×10~7CFU/m L,最佳施药时间为接种病菌前8 h,对4种叶斑病的预防效果分别达80.83%、84.62%、84.33%和87.74%。田间试验表明,Y2悬浮剂对4种病害的预防效果分别为65.90%、69.21%、67.97%和70.22%。

Control Effects of Bacillus amyloliquefaciens 9601-Y2 on Corn Leaf Spots

In order to clarify its controlling effect on corn leaf spots, using concave slide method, conidia germination of the fungi(Exserohilum turcicum, Cochliobolus heterostrophus, Cochliobolus carbonumand Curvularia lunata) was determined with fermentation liquid, supernatant and Bacillus spores. The germination inhibition rates were 82.72%, 76.71% and 4.89% for E. turcicum; 88.04%, 82.85% and 5.63% for C. heterostrophus; 84.9%, 79.9% and 10.81% for C. carbonum; 98.79%, 95.05% and 6.23% for C. lunata, respectively. Through the greenhouse pot experiment, the suitable concentration of Y2 was 1×10⁷ CFU/mL, and the best application time was 8 hours before the pathogen inoculation. Preventive effects for four leaf spot diseases with Y2 fermentation liquid were 80.83%, 84.62%, 84.33% and 87.74%, respectively, in the greenhouse. Correspondingly, the biocontrol agent Y2 SC could prevent 65.90%, 69.21%, 67.97% and 70.22% of the four diseases in the field through its curing effect was not as well as preventive one.