Abstract:

Club root is a major disease that severely hampers the development of oilseed rape industry and can occur at the seedling stage. At present, the main control measures of this disease including using resistance varieties and fungicides, but the problem of pesticide residues is becoming more and more serious, so the biological control strategy is proposed to prevent and control club root of oilseed rape. To study the control effect of Bacillus Bam22 on the club root of oilseed rape, seed mixing and root irrigation at seedling stage were used in the study. The results showed that the seed mixing with Bacillus Bam22 combined with root irrigation at seedling stage could effectively reduce the disease incidence, improve the control effect on the club root, and promote the growth of oilseed rape. At the seedling stage, compared with water treatment (CK), the incidence of Bacillus Bam22 treatment (T1) and Bacillus Bam22 and Kaolin treatment (T2) was decreased by 3.4%-20%, and the control efficiency reached 44%-52%; compared with 10% cyazofamid treatment (T3), the control efficiency of T1 and T2 was improved by 20%-40%. At the flowering stage, compared with CK, the incidence rate of T1 and T2 was decreased by 10%-13%, and the control efficiency reached 44%~52%; compared with T3, the incidence rate was decreased by 6.67%-10%, the control efficiency was improved by 5%-22%, the yield per plant was increased by 23.97% -34.29%. In conclusion, the use of Bam22 in seed mixing and root irrigation at seedling stage can effectively reduce the incidence of club root of oilseed rape during seedling and flowering stage, and significantly bring down the yield loss rate. Bam22 has good control efficiency on club root and the potential to be developed into biological fungicide.

Key words: Bacillus Bam22, oilseed rape, club root, control efficiency, yield