Effects of Fertilizer Rates on Severity of Xanthomonas Leaf Spot of Schefflera and Dwarf Schefflera. A. R. Chase, Associate Professor of Plant Pathology, University of Florida, IFAS, Agricultural Research and Education Center, 2807 Binion Road, Apopka 32703. R. T. Poole, Professor of Ornamental Horticulture, University of Florida, IFAS, Agricultural Research and Education Center, 2807 Binion Road, Apopka 32703. Plant Dis. 71:527-529. Accepted for publication 20 January 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0527.

Severity of Xanthomonas leaf spot of Brassaia actinophylla (schefflera) and Schefflera arboricola (dwarf schefflera) caused by X. campestris pv. hederae was negatively correlated with fertilizer rates up to five times those recommended for schefflera and dwarf schefflera. Plant growth was not affected over this fertilizer range, although elemental content of schefflera and dwarf schefflera were affected. As fertilizer rate increased, levels of nitrogen, phosphorus, and potassium increased; levels of sulfur, iron, manganese, boron, copper, and zinc were unaffected; and levels of magnesium, sodium, and calcium decreased.