Selective Medium for Isolating Lasiodiplodia theobromae . A. J. CILLIERS, Department of Microbiology and Biochemistry, University of the Orange Free State, Bloemfontein, 9300, South Africa. W. J. SWART, Department of Plant Pathology, and M. J. WINGFIELD, Department of Microbiology and Biochemistry, University of the Orange Free State, Bloemfontein, 9300, South Africa. Plant Dis. 78:1052-1055. Accepted Tor publication 14 June 1994. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-1052.

Six chemicals were tested in vitro for their effect on the growth of Lasiodiplodia theobromae. Three were selected for further evaluation on 14 of the fastest growing fungi commonly associated with L. theobromae on Pinus elliottii seeds. Tannic acid suppressed Rhizopus sp., Drechslera sp., Trichoderma sp., and Sphaeropsis sapinea, four of the fastest growing test fungi. Benodanil and tridemorph suppressed most of the other fungi. The selective medium, consisting of 33.6 g/L of malt extract agar (MEA), 3,000 ?g/ml of tannic acid, 50 Μg/ml of benodanil, and 0.5 Μg/ml of tridemorph, was effective in suppressing all fungi selected for testing except L. theobromae. The selective medium was also more effective than MEA for isolating L. theobromae from soil, woody tissue, and P. elliottii seeds.