Pathogens of Ice Plant in California. J. D. MacDonald, Associate Professor, Department of Plant Pathology, University of California, Davis 95616. J. R. Hartman, Extension Professor, Department of Plant Pathology, University of Kentucky, Lexington 40546; and J. D. Shapiro, Staff Research Associate, Department of Plant Pathology, University of California, Davis 95616. Plant Dis. 68:965-967. Accepted for publication 30 April 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-965.

Ice plants (Carpobrotus spp.) are commonly grown as ground covers in California. In many areas, plantings of all ages have shown decline symptoms that include wilting, yellowing, or death of individual plants or large patches of plants. Pythium aphanidermatum and Phytophthora cryptogea were isolated from decayed lower stems, crowns, and roots of plants growing in poorly drained soils. Phomopsis sp. was isolated from orange-discolored stem tissues at the margin between wilted and healthy branch parts of plants growing in several locations. Verticillium dahliae was isolated from stems of severely wilted plants collected in southern California. Inoculations of healthy ice plants have confirmed the pathogenicity of each of these fungi. Fusarium sp., Macrophomina sp., and Pestalotia sp. were also isolated from diseased ice plants, but pathogenicity of these fungi could not be confirmed.