Abstract
A pathogen that causes blight of longleaf pine seedlings in nurseries in Florida that was originally identified as Rhizoctonia solani is described in this paper as a binucleate R. solani-like fungus. The fungus belongs to anastomosis group 3 of Ceratobasidium spp. (CAG 3) on the basis of anastomosis trials with isolates representing six anastomosis groups. In greenhouse trials, longleaf pine seedlings grown in autoclaved soil infested with an isolate of the fungus showed symptoms of both preemergence and postemergence damping-off. Over a 2-yr period in commercial forest tree nursery, losses associated with blight caused by this organism varied with seed lot age and ranged from 0.4 to 18.9%.