MICROBIAL SELECTION-STRATEGIES THAT ENHANCE THE LIKELIHOOD OF DEVELOPING COMMERCIAL BIOLOGICAL-CONTROL PRODUCTS

Research interest in utilizing microorganisms to create a microbial en vironment suppressive to plant pathogens has increased exponentially i n recent years, Despite intense interest in developing biological cont rol agents, relatively few antagonists have achieved 'commercial produ ct' status, The fact that such a small proportion of active laboratory antagonists are developed into biological control products is partly due to several features common to microbial selection strategies that are widely utilized to obtain putative biological control agents: (a) relatively few candidate microorganisms are tested; (b) microbes are s elected based on the results of an assay that does not replicate field conditions; and (c) the amenability of microbes to commercial develop ment is excluded as a selection criterion, Selection strategies that e nhance the likelihood of developing commercial biological control prod ucts are described, These include making appropriate choices regarding the pathosystem for biological control, the method of microbe isolati on, and the method of isolate characterization and performance evaluat ion, A model system of developing a biological control product active against Gibberella pulicaris (Fries) Sacc, (anamorph: Fusarium sambuci num Fuckel), the primary causal agent of Fusarium dry rot of stored po tatoes, is used to illustrate the proposed selection strategy concepts , The crucial importance and methodology is described, of selecting st rains with enhanced potential for commercial development based on a st rain exhibiting both favorable growth kinetics and bioefficacy when gr own in commercially feasible liquid media.