Seedling blight of longleaf pine caused by a binucleate Rhizoctonia solani-like fungus

sand accumulates around the needle bases and terminal buds. Such accumulation, sometimes referred to as "sand splash" (5), provides warm, humid conditions that apparently are conducive to seedling infection. Sand accumulation also may bring pathogen propagules into contact with susceptible host tissues. Since the early reports of this seedling blight in Florida, detailed examination of the pathogen has revealed that it does not exhibit the multinucleate condition typical of R. so/ani (1. T. English and R. C. Ploetz, unpublished). Instead, a binucleate condition has been observed. We have isolated binucleate forms of R. so/ani-Iike fungi from diseased long leaf pine seedlings in four forest tree nurseries and two outplant sites in Florida. All isolates examined showed characteristics of R. so/ani, including right-angle ABSTRACT English, J. T ., Ploetz, R. C., and Barnard, E. L. 1986. Seedling blight of longleaf pine caused by a binucleate Rhizoctonia solani-Iike fungus. Plant Disease 70:148-150.