向日葵锈病生防细菌筛选及与杀菌剂复配的相对防效OA

Sunflower rust,caused by Puccinia helianthi,is a major disease affecting sunflowers.Currently,chemical control remains the primary method for managing this disease.However,this approach is not favorable for green and sustainable development of sunflower production.This study conducted indoor toxicity testsand indoor ef-ficacy tests on seven strains of biocontrol bacteria:Bacillus thuringiensis NMB1,B.amyloliquefaciens NMB3,B.megaterium NMB4,Burkholderia pyrrocinia XXB24,Acinetobacter oleivorans NMB17,Pseudomonas fluorescens Pf27,and B.subtilis Y2 to evaluate their effectiveness against sunflower rust disease.The results demonstrated that all seven biocontrol strains exerted inhibitory effects on the germination of the rust urediospores.The Y2,Pf27,and NMB4 strains ranked among the top three in inhibitory efficacy.The compatibility test of the compound agents showed strains Y2,NMB4,and Pf27 had a good compatibility with each other.0.3％eugenol was compatible with Y2,NMB4,and Pf27,while 80％tebuconazole was only compatible with Pf27.The results of combination assays be-tween biocontrol strains as well as between biocontrol strains and fungicides showed that the most pronounced syner-gistic inhibitory effects were achieved with the following mixtures:NMB4 and Pf27 at a 5∶5 volume ratio,0.3％plant-derived fungicide eugenol and Y2 at a 4∶6 volume ratio,and 80％chemical fungicide tebuconazole and Pf27 at a 5∶5 volume ratio.Potted plant control trials indicated that all seven biocontrol strains exhibited certain levels of efficacy against rust disease,with Y2 showing the highest control efficacy(65.47％).Among different combination modes,the highest control efficacy was observed with Y2 and Pf27 mixed at a 5∶5 volume ratio(68.65％),0.3％eu-genol and Y2 at 4∶6(86.46％),and 80％tebuconazole and Pf27 at 5∶5(89.59％).These research results can provide valuable guidance for the practical application of biocontrol bacteria in managing this disease.