New Leaf Spot Disease of Calathea and Maranta spp. Incited by Drechslera setariae. G. W. Simone, Assistant Professor and Extension Plant Pathologist, University of Florida Institute of Food and Agricultural Sciences, Gainesville 32611. D. D. Brunk, Plant Disease Diagnostic, Inc., 2655 Hwy 436, Suite 5, Apopka, FL 32703. Plant Dis. 67:1160-1161. Accepted for publication 19 May 1983. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-1160.

Drechslera setariae was identified as the causal agent of a new leaf spot disease on Calathea and Maranta spp. Leaf lesions on Maranta spp. were round to slightly irregular, 2–12 mm in diameter, and narrowly zonate, with a 2–3 mm chlorotic halo. Leaf spots on Calathea spp. were elongate to irregular, 2–16 mm in diameter, usually without zonation or chlorotic halo, and often vein-delimited. Isolates of D. setariae from Maranta and Calathea were cross-pathogenic and also pathogenic on species of Ctenanthe and Stromanthe, causing lesions ranging from necrotic flecks to lesions similar to those produced on Calathea spp.