Influence of soil fumigation and source of strawberry plants on population densities of spores and infective propagules of endogonaceous mycorrhizal fungi

Fumigation of soil with methyl bromide-chloropicrin (2:1, w/w) killed all detectable infective propagules of endogonaceous fungi in one field and reduced those in another to a trace. However, spore population densities were reduced by only half in the first field and not affected in the second. These effects persisted overwinter in the first field and through the growing season in the second. Apparently spores killed by fumigation do not degrade in soil readily. No evidence was obtained that commercial strawberry transplants were an important source for introduction of endogonaceous fungi.