Biological Control of Sclerotinia Wilt of Sunflower with Talaromyces flavus and Coniothyrium minitans. D. L. McLAREN, Research Station, Agriculture Canada, Box 29, Beaverlodge, Alberta TOH 0C0. H. C. HUANG and G. C. KOZUB, Research Station, Agriculture Canada, Box 3000 Main, Lethbridge, Alberta T1J 4B1; and S. R. RIMMER, Department of Plant Science, University of Manitoba, Winnipeg R3T 2N2. Plant Dis. 78:231-235. Accepted for publication 27 October 1993. Copyright 1994 Department of Agriculture, Government of Canada. DOI: 10.1094/PD-78-0231.

Six field experiments were conducted in Manitoba and Alberta during 1982-1987 to evaluate the hyperparasites Talaromyces flavus and Coniothyrium minitans for the control of Sclerotinia wilt, caused by Sclerotinia sclerotiorum, of sunflower. Application of T. flavus and C. minitans to soil at seeding time reduced disease incidence and subsequent loss in seed yield. Plots treated with T. flavus and/or C. minitans for two consecutive years developed a suppressive effect to S. sclerotiorum in the third year but not in the fourth year. The application of combinations of T. flavus and C. minitans was as effective as the application of C. minitans alone

Keyword(s): Helianthus annuus, mycoparasites