对作物根癌病具有良好防治效果的放射形土壤杆菌（Ａｇｒｏｂａｃｔｅｒｉｕｍｒａｄｉｏｂａｃｔｅｒ）Ｋ８４进行了发酵试验，确定了培养基配方及培养条件。最适发酵周期为２４～３０ｈ；发酵液含活菌体数达５×１０１２／ｍＬ。为该制剂的商品化提供了一整套试验数据。发酵液经后处理而制成的生物农药产品定名为“根癌宁”（Ｄｅｃａｌｉｎｇ）。 Fermentation experiments on Agrobacterium radiobacter K84, which has good control effect on crop root disease, were conducted to determine the medium formula and culture conditions. The optimum fermentation period was 24 ~ 30h; the number of viable cells in fermentation broth was 5 × 1012 / mL. A complete set of test data was provided for the commercialization of the formulation. The biocide product made from the fermentation broth after-treatment is named “Decaling.”