Date of this Version
Harveson, R. M., Steadman, J. R., and Urrea, C. A. 2010. Integrating planting dates and fungicide applications for managing white mold of dry beans in western Nebraska. Online. Plant Health Progress doi:10.1094/PHP-2010-0701-02-RS.
White mold, caused by the soilborne fungus Sclerotinia sclerotiorum, is one of the most destructive diseases of common beans (Phaseolus vulgaris L.) and is greatly influenced by environmental conditions and certain agronomic practices. A 3-year study (2003 to 2005) evaluated planting date and thiophanate-methyl fungicide applications based on decision aids consisting of blue plate technique, sugar beet Cercospora leaf spot (CLS) disease forecasting model, and crop phenology (90% bloom). Overall yields were lower in 2003 and higher in 2005, and disease severity was greater in 2004. Planting dry beans in late June to early July resulted in higher levels of disease than planting in late May or mid-June in 2004. Late planting also resulted in lower yields and 100-seed weight in 2004 and 2005 than the early and mid-plantings. Compared to the control and CLS model, fungicide applications based on the blue plate and 90% bloom treatments reduced disease severity in 2004 and 2005, while also increasing 100-seed weight and yields in 2004.