Abstract
The ability of Bacillus subtilis to inhibit Ophiostoma perfectum on sapwood of ponderosa pine (Pinus ponderosa Laws.) was studied over a 28-day period in laboratory trials. The bacteria reduced but did not completely inhibitfungal discoloration. Scanning electron microscope (SEM) examination revealed that the bacteria and fungi were often intimately associated on the wood surface and bacterial populations were generally lower on wafers where the stain fungi were also present. These results indicate that the bacteria may have inhibited the stain fungi through competition for nutrients or space, rather than by antibiosis. This may have important implications for biocontrol strategies using this bacterium.