Fungicidal Effects of Some Acaricides on Mycosphaerella citri. J. O. Whiteside, Plant Pathologist, University of Florida, Agricultural Research and Education Center, Lake Alfred 33850. Plant Dis. 67:864-866. Accepted for publication 10 January 1983. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-864.

Among acaricides applied to citrus trees in Florida, chlorobenzilate, cyhexatin, dicofol, and sulfur were fungicidal to Mycosphaerella citri, the greasy spot pathogen. Carbophenothion, dialifor, dioxathion, ethion, fenbutatin oxide, and propargite exhibited relatively little or no such activity, even in vitro at 200 μg a.i./ml. In greenhouse tests on leaves of rough lemon (Citrus jambhiri) inoculated with M. citri, applications of chlorobenzilate, cyhexatin, dicofol, and sulfur during a 10- to 12-day infection period consistently reduced greasy spot severity. Only sulfur and cyhexatin, and sometimes dicofol, reduced greasy spot severity when applied 4–7 days before inoculation. In the field, two foliar spray treatments of grapefruit (Citrus paradisi) trees with sulfur or dicofol, but not chlorobenzilate, reduced greasy spot severity. This effect, however, was too slight to consider sulfur or dicofol as possible substitutes for copper fungicides or spray oil for greasy spot control.