五种生物源杀菌剂苗期对小麦白粉病的防效

Control Effects of Five Biological Fungicides on Wheat Powdery Mildew at Seedling Stage

本试验选择5种生物源杀菌剂枯草芽孢杆菌、多抗霉素、大黄素甲醚、蛇床子素、吡唑醚菌酯和2种常用三唑类化学杀菌剂己唑醇、三唑酮共7种药剂进行了苗期室内小麦白粉病防治药效比照试验。预防作用表明,多抗霉素50×、100×,枯草芽孢杆菌100×、200×与大黄素甲醚、蛇床子素、吡唑醚菌酯所试各浓度相比可以延迟病菌分生孢子出现时间。大黄素甲醚、蛇床子素相比吡唑醚菌酯所试浓度可以延迟病菌分生孢子出现时间。喷药后13天,枯草芽孢杆菌50×、100×、200×相对防效分别为58.16%、82.53%、92.05%。多抗霉素50×、100×、200×相对防效分别为92.78%、92.28%、78.77%。大黄素甲醚50×、100×、200×相对防效分别为25.63%、20.71%、22.70%。蛇床子素50×、80×、100×相对防效分别为51.26%、51.15%、58.26%。吡唑醚菌酯200×、500×、800×相对防效分别为46.65%、28.77%、27.09%。以多抗霉素和枯草芽孢杆菌各浓度处理的相对防效为高。枯草芽孢杆菌、大黄素甲醚、蛇床子素所试浓度不是越高越好。多抗霉素50×相比枯草芽孢杆菌、大黄素甲醚、蛇床子素、吡唑醚菌酯所试浓度预防效果持效性好,喷药后19天相对防效为43.00%。治疗作用表明,吡唑醚菌酯200×、500×处理和三唑酮各浓度处理在喷药2天后初查和喷药4天后进一步调查时均有好的治疗作用,接菌6天后对病原菌侵染抑制效果速效性好于其它4种生物源杀菌剂和己唑醇各浓度处理。喷药4天后,吡唑醚菌酯与三唑酮、己唑醇各浓度处理均未见发病,相对防效达100.00%。吡唑醚菌酯治疗效果好于其它4种生物源杀菌剂。枯草芽孢杆菌50×、多抗霉素50×、蛇床子素50×、大黄素甲醚100×相对防效分别为96.30%、97.80%、68.50%、24.20%。

Five biological fungicides Bacillus subtilis, polyoxin, physcion, osthol, pyraclostrobin and two common triazole fungicides hexaconazole and triadimefon were selected to conduct comparative tests on the control effects of wheat powdery mildew at seedling stage. Preventive effect shows polyoxin 50×, 100×, Bacillus subtilis 100×, 200×compared with trial concentration of physcion, osthol, pyraclostrobin can delay the emergence time of pathogen conidia. Trial concentration of physcion, osthol compared with pyraclostrobin can delay the emergence time of pathogen conidia. 13 days after spraying, the relative control effect of 50×, 100×and 200×of Bacillus subtilis was 58.16%, 82.53% and 92.05%, respectively. The relative control effect of 50×, 100×and 200×of polyoxin was 92.78%, 92.28% and 78.77%, respectively. The relative control effect of 50×, 100×and 200×of physcion was 25.63%, 20.71% and 22.70%, respectively. The relative control effect of 50×, 80×and 100×of osthol was 51.26%, 51.15% and 58.26%, respectively. The relative control effect of 200×, 500×and 800×of pyraclostrobin was 46.65%, 28.77% and 27.09%, respectively. The relative control effect of polyoxin and Bacillus subtilis was higher. Trial concentration of Bacillus subtilis, physcion and osthol is not the higher the better. Compared with the different trial concentration of Bacillus subtilis, physcion, osthol and pyraclostrobin, polyoxin 50×has better and longer prevention effect. 19 days after spraying, the relative control effect was 43.00%. Therapeutic effects show that the treatments of 200×and 500×pyraclostrobin and triadimefon at different concentrations showed good therapeutic effects in initial examination after 2 days of spraying and further investigation after 4 days of spraying. After 6 days of inoculation, the inhibition effect on pathogen infection was faster than that of other 4 biological fungicides and hexaconazole at different concentrations. After 4 days of spraying, no disease was found in pyraclostrobin, triadimefon and hexacona-zole, and the relative control effect was 100.00%. The therapeutic effect of pyraclostrobin was better than the other four biological fungicides. The relative control effects of 50×Bacillus subtilis, 50×polyoxin, 50×osthole and 100×physcion were 96.30%, 97.80%, 68.50% and 24.20%, respectively.