Abstract: A novel means for identifying selective control agents for weeds, pests, and microbes is provided. Novel compositions for the selective control of weeds, pests, and microbes are also provided. The critical elements in the novel method of the invention relate to the systematic and specific identification of points of diversity which exist between the target organism and the host or other non-target organisms. More specifically the process involves identifying a difference which exists between the metabolic pathway of a microbial or plant target organism and a non-target host specie and then preparing a control agent which perturbs the metabolic pathway of the target without significantly perturbing the metabolic pathway of the host.