Sclerotinia sclerotiorum survives in seed through two mechanisms, infected seed and infested seed bags contaminated with survival structures, sclerotia (Tu, 1988). The ability of the pathogen to persist for extended periods is due to the prolonged survival of sclerotia (~10 years; Abawi and Grogan, 1979;Ben-Yephet et al., 1993), essentially made up of melanized mycelial masses which accumulate once the infection cycle has been completed or interrupted (Willetts and Bullock, 1992). Seed-borne S. sclerotiorum and sclerotia infested