positively regulates positive regulation of developmental process biological regulation appressorium formation regulation of appressorium formation positive regulation of appressorium formation positive regulation of appressorium formation on or near host Any process that activates or increases the frequency, rate or extent of symbiont appressorium formation. Note that this term should not be used to annotate gene products of the host. It should only be used to annotate those gene products from the symbiont involved in this process. GO:0075018 biological_process