Technical Abstract: In August 2007 root samples were collected from an existing fumigation plot in which trees were planted January 2007. Trap cultures of Sudan grass were established to multiply the residual AM fungus. A special nutrient medium was applied to irrigate Sudangrass for boosting AM innoculum production. AM spores were produced in January 2008 and used to inoculate almond rootstocks planted in February 2008. Roots of Sudan grass from trap cultures were analyzed for AM fungal colonization by fumigated and non-fumigated soils. Five hundred and fifty root fragments (I cm long) were stained with trypan blue and scored for colonization. 60% roots from non-fumigated soil were colonized. About 40% of the roots from fumigated soil were colonized. The data indicate that fumigation did reduce residual soil AM population. Preliminary results indicate that Glomus Mosseae, Glomus 3, Gigasproa rosea, Glomus intraradices were present in the soil and in colonized roots.