Control of Apothecial Production of Sclerotinia sclerotiorum by Coniothyrium minitans and Talaromyces flavus. D. L. McLaren, Research Centre, Agriculture and Agri-Food Canada, P. O. Box 3000, Lethbridge, AB, Canada. H. C. Huang, Research Centre, Agriculture and Agri-Food Canada, P. O. Box 3000, Lethbridge, AB, Canada T1J 4B1; S. R. Rimmer, Department of Plant Science, University of Manitoba, Winnipeg, MB, Canada R3T 2N2. Plant Dis. 80:1373-1378. Accepted for publication 28 August 1996. Copyright 1996 Department of Agriculture and Agri-Food, Government of Canada. DOI: 10.1094/PD-80-1373.

In seven field experiments conducted in Alberta from 1984 to 1987, the application of Coniothyrium minitans to soil at seeding time reduced apothecial production of sclerotia of Sclerotinia sclerotiorum under the canopies of bean, canola, wheat, and barley. Application of Talaromyces flavus was ineffective, and combinations of T. flavus and C. minitans were as effective or less effective than C. minitans alone, indicating that no synergism occurred between these hyperparasites. Application of C. minitans to soil in the spring reduced apothecial production from sclerotia of S. sclerotiorum buried in the soil, and increased parasitism on sclerotia produced on diseased bean plants.

Keyword(s): Brassica napus, B. rapa, carpogenic germination, Hordeum vulgare, Phaseolus vulgaris, Triticum aestivum, white mold