The purpose of this paper is to explain the influences of the sorts of fertilizer upon the needle blight of Sugi (Japanese Ceder) seedlings in the nurseries. In, our nursery-beds of volcanic ash soil, which has been cultivated for some years, the following results were obtained by the Latin-square method: By changing the ratio or amount of three elements of fertilizer (N, P₂O₅ and K₂O) the damages of needle blight could not be checked perfectly. The damage was reduced by incresed the ratio of potash or by balanced ratio and amounts of three elements fertilizer, by giving an excessive amount of nitrogenous fertilizer the damage was induced severely, but the effect of phosphoric fertilizer and time to the damage was not so remarkable as potash.