Effect of ground Brassica seed meal on control of Rhizoctonia damping-off of cabbage

Ten cultivars of three Brassica species were compared for volatile compounds in hydrated ground seeds that were fungicidal to Rhizoctollia solani AG-4. Among the samples tested, the volatile substances in the ground seed of mustard (Brassica juncea cv. Ban Sin) showed the strongest fungicidal effect. Allyl isothiocyanate was one of the predominant fungicidal compounds detected in the ground seed of all Brassica species tested, and the amount was the highest in ground mustard seed meals. Among the nine carriers tested for seed coating with ground mustard seed meal, Biolan peat 133 was the most effective for the seed treatment. Cabbage seeds treated with a mixture of ground mustard seed meal and Biolan peat 133 (MBF mixture) at 2:3 ratio (w/w) resulted in a significant reduction in incidence of Rhizoctonia damping-off with no harmful effects to the germination of treated seeds. Effective control of Rhizoctollia damping-off of cabbage by the seed treatment with the MBF mixture was also obtained in a large-scale experiment conducted in a commercial automated environment-control led greenhouse. This study suggests that the MBF mixture has potential for use in the commercial seed treatment.