This research was carried out under the guidance of the chief of this station and in combination with the protection section. Since last year, we have performed the foundamental experiments concerning the prevention and the removing of diseases of plants. If the results were applied to seed-bed and some influence might be observed, it should be utilized to the undertaking. Among the above experiments, the application of wood vineger was prominent and its results of the prevention and the removing of this disease may be largely expected. The mulching of seed-bed has various profit, but in the-other respect, it may be liable to be the cause of this disease. Therefore, a great care should be payed. This may be a problem to be experimented, which needs a rapid inprovement in futures.