Root rot is a major disease on snap beans and occurs throughout the bean-growing areas in New York. Over the years, monoculture of beans, improper crop rotations, and increased soil compaction have intensified the prevalence and severity of bean root rot. Economic losses due to this disease have been considerable although they are variable among fields during the same growing season, and in the same field from year to year. Generally, root rot is most severe and causes the greatest damage to beans when cool and wet weather occurs from seeding time to about three weeks after planting, followed by hot dry weather.