Effect of Nitrogen and Potassium Fertilizer Rates on Severity of Xanthomonas Blight of Syngonium podophyllum. A. R. Chase, Professor of Plant Pathology, University of Florida, IFAS, Central Florida Research and Education Center, Apopka 32703. . Plant Dis. 73:972-975. Accepted for publication 8 July 1989. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0972.

Syngonium podophyllum ‘White Butterfly’ plants were grown under various nutritional regimes before inoculation with Xanthomonas campestris pv. syngonii. Percentage of blighted leaf area decreased linearly as the rate of complete fertilizer (liquid 20:20:20 or slow-release 19:6:12) increased. Increased rates of either nitrogen or potassium were equally effective in reducing symptom expression. Plant response (number of leaves, height, and top quality) to increasing rates of complete fertilizer was generally described by a quadratic function, and good plant growth occurred over a wide range of fertilizer rates. Plant height and leaf number were not affected by N-K ratio, and fresh top weight showed a quadratic response to nitrogen rate only. Severity of Xanthomonas blight of S. podophyllum ‘White Butterfly’ can be minimized with moderate increases in application rates of complete fertilizer, nitrogen, or potassium.