It is intended to provide an agent for elevating resistance against plant diseases whereby the resistance against plant diseases and pest insects are elevated by using a yeast-origin component, the safety of which has been established as a food, so that it is expected to strength a plant, enable the raising of good seedlings and, in its turn, enable the production of a crop with favorable qualities at a high yield. Namely, an agent for elevating plant disease-resistance which contains a yeast cell wall digestion product is provided. Also, a controlling material for a specific use which contains a yeast cell wall digestion product and is usable for imparting plant disease-resistance is provided. Moreover, use of a yeast cell wall digestion product for elevating plant disease-resistance is provided. Further, a method of elevating the effect of elevating plant disease-resistance of a plant activator by adding a yeast cell wall digestion product to the plant activator is provided. Furthermore, a cultivation method which comprises supplying the above-described agent for elevating plant disease-resistance to young seedlings and/or seedlings after setting is provided.
