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Selective Medium for Isolating Sphaeropsis sapinea. W. J. Swart, Plant Protection Research Institute, Private Bag X5017, Stellenbosch 7600, South Africa; M. J. Wingfield(2), and P. S. Knox-Davies(3). (2)Plant Protection Research Institute, Private Bag X5017, Stellenbosch 7600, South Africa; (3)Department of Plant Pathology, University of Stellenbosch, Stellenbosch 7600, South Africa. Phytopathology 77:1387-1389. Accepted for publication 25 March 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/Phyto-77-1387.

Seventeen fungicides were tested in vitro for their effect on the growth of Sphaeropsis sapinea. Ten were selected for further evaluation on 14 contaminant fungi commonly associated with S. sapinea in host tissue. Benodanil and rose bengal suppressed all test fungi more than S. sapinea. Chlorothalonil and o-phenylphenol were the most effective inhibitors of Trichoderma sp. and Mucor sp., the two fastest-growing contaminants. A selective medium comprising Difco agar (20 g/L), Difco malt extract (10 g/L), rose bengal (50 µg/ml), benodanil (10 µg a.i./ml), chlorothalonil (1 µg a.i./ml), and o-phenylphenol (lµg a.i./ml) was more effective for isolating S. sapinea from woody tissue than malt extract agar (MEA) alone, or a previous MEA medium containing tannic acid.