PROBLEM TO BE SOLVED: To provide a nonpathogenic bacterial strain exhibiting stable plant disease-controlling effects even in an actual crop-producing site, also exhibiting effects except the plant disease control, and safely usable as a microbial pesticide and the like, and to provide a new plant disease-controlling agent and the like using the strain.SOLUTION: There are provided an agent for controlling bacterial plant disease such as an agent for controlling black rot of Cruciferae, an agent for controlling bacterial spot of Solanaceae, an agent for controlling bacterial spot of lettuce, an agent for controlling bacterial shot hole of peach and an agent for controlling cankar of citrus fruits, a pest controller such as agents for controlling aphids and/or spider mites, a plant growth accelerator such as a promoter for promoting seed germination of goosefoot family plants, and the like, containing one or more microbial cells selected from two strains of Xanthomonas sp. 11-100-01 strain (NITE P-1243) and Xan
