Could the late blight pathogen survive in soil between seasons?
Unlikely except in affected potato tubers. This is an obligate pathogen that is thought to only be able to survive in living plant tissue in the northeastern US. It can produce a specialized structure that would enable it to survive without living plant tissue, but this requires that the pathogen reproduce sexually which it is not thought to be able to do in the northeastern US. When late blight has previously developed in this region and the pathogen population has been examined, only one mating type has been found. This is the term used for the pathogen’s equivalent of male/female. Thus the pathogen has only been able to reproduce asexually. The characteristic white growth that develops on late blight affected tissue contains many asexually-produced spores. Both mating types have been found in Florida.
