抄録
In Japan most farmers apply the transplanting method for onion crops. Fusarium basal rot occurs in nursery bed, main field and seed farm. The typical symtom of the disease is wilt of leaves and browning of stem-plate. The present work aimed at both ecological study on the ontbreak of the disease and the method of prevention of the disease. The causal fungus,F. oxysporum f. sp. cepae, was isolated in high frequency from symptomless stem-plate as well as browning one. Histological observation showed that the fungus entered into the stem-plate through the dead tissues attached among roots or dead roots. The disease was controlled by dipping of seedlings or mother onions in aqueous solution of "Benlate-50% W.P."
