| 摘要 |
PURPOSE: To provide the subject agent effective for Plasmodiophora brassicae Woronin and nematodes giving large damages to agricultural products and capable of contributing to the increase in their yields and the improvement of their qualities, by employing a specific compound or a natural material containing the same. CONSTITUTION: Mannitol and/or a natural material containing the mannitol is employed. The mannitol is produced e.g. by subjecting sucrose to a high pressure reduction or further by allowing the reduced product to pass through an ion exchange resin and subsequently crystallizing the treated sucrose. The natural material may as such be used as the natural material containing the mannitol. The natural material may be used as e.g. its dried product or its powder. The natural material includes a sea alga such as Laminaria digitata, an Oleaceae plant, a mushroom and a lichen. When used as the parasite control agent or an agricultural chemical, the mannitol or the natural material is used at a dose of 400g to 3kg (as the mannitol) per 10a of a field after absorbed or adsorbed in active carbon, etc. |
