Evaluation of Dry Bean Germplasm and Cultivars for Partial Field Resistance and Physiological Resistance to Sclerotinia sclerotiorum (white mould)

Canadian dry bean cultivars and select dry bean germplasm lines were evaluated for white mould resistance. Partial field resistance to white mould was assessed by growing bean lines in inoculated disease nurseries at Winkler and Brandon, MB and Lethbridge, AB.  Partial Field Resistance: The white mould disease incidence data from the three nurseries each in 2009, 2011 and 2012, and from the Winkler nursery in 2010 (Lethbridge and Brandon nurseries were lost due to waterlogging in 2010) indicate the differences between dry bean genotypes for disease incidence and severity were significant and fairly consistent. Partial Physiological Resistance: This study was completed in 2010. The differences in disease severity between dry bean genotypes were significant at 16 and 26 days after inoculation. White mould disease severity rating for all of the genotypes increased over time. The dry bean cultivars developed in Canada lacked both partial field and partial physiological resistances when grown under high disease pressure. This study determined that the germplasm lines A195, G122, I9365-31, and L 192 expressed both partial field and physiological resistance.