VIEW ARTICLE

Disease Control and Pest Management

Fungitoxic Activity of Efosite Aluminum on Growth, Sporulation, and Germination of Phytophthora parasitica and P. citrophthora. A. Farih, Department of Plant Pathology, University of California, Riverside 92521, Present address of senior author: Institut Agronomique et Veterinaire Hassan II, Rabat, Morocco; Peter H. Tsao(2), and John A. Menge(3). (2)(3)Department of Plant Pathology, University of California, Riverside 92521. Phytopathology 71:934-936. Accepted for publication 16 December 1980. Copyright 1981 The American Phytopathological Society. DOI: 10.1094/Phyto-71-934.

Efosite Al was not highly inhibitory to mycelial growth but was slightly more active against Phytophthora citrophthora than against P. parasitica; the ED₅₀ values were 1,146 and 285 mg/L at 3 days and 929 and 56 mg/L at 7 days for P. parasitica and P. citrophthora, respectively. Formation of sporangia, chlamydospores, and oospores was highly sensitive to efosite Al, but zoospore germination, chlamydospore germination, and germ tube growth were insensitive to low concentrations (100 mg/L or less) of the fungicide. Indirect sporangium germination of P. parasitica was more sensitive to efosite Al than that of P. citrophthora. Because of its activity against sporulation of both Phytophthora spp., efosite Al can be considered an antisporulant compound.