First Report of Dry Top Rot of Sugarcane in Florida: Symptomatology, Cultivar Reactions, and Effect on Stalk Water Flow Rate. J. C. COMSTOCK, Research Plant Pathologist, USDA-ARS, Sugarcane Field Station, Canal Point, FL 33438. J. D. MILLER, Research Leader, USDA-ARS, Sugarcane Field Station, Canal Point, FL 33438; and D. F. FARR, USDA-ARS, Systematic Botany and Mycology, Beltsville, MD 20705. Plant Dis. 78:428. Accepted for publication 5 January 1994. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source The American Phytopathological Society, 1994. DOI: 10.1094/PD-78-0428.

Dry top rot, caused in sugarcane by Ligniera vasculorum (Matz) Cook, was detected at the USDA-ARS Sugarcane Field Station, Canal Point, Florida, on 13 November 1991 in CP 88-Series clones. This is the first report of the disease in Florida; previous reports of the disease were in the 1920s and 1930s in Puerto Rico. It also has been reported in Barbados, Cuba, and Venezuela. Overall symptoms include initial drying of the spindle leaf tips, subsequent drying of the upper leaves, reduced growth of the top internodes of the stalk, gradual shrinking and drying of stalks, and finally stalk death. Masses of orange-brown spores, 17-25 μm diameter, were present in the xylem cells of the vascular bundles of the basal internodes. Water flow in symptomatic stalks was restricted. The disease incidence of cultivars was variable.