Brian Hall, Chris Gillard
Root Rots of Dry Beans
Compiled by Brian.Hall, OMAF Stratford
Chris Gillard, RCAT, University of Guelph
Root rot, damping-off, and seed rots are major soil-borne fugal pathogens widespread throughout dry bean growing areas. Yield losses from root rot range from a trace to 100 percent, especially if adverse environmental conditions persist after planting through flowering. Compact and poorly drained soils tend to have more root rot. The most common root rot pathogens are Fusarium root rot or dry rot (Fusarium solani), Rhizoctonia root and pod rot (Rhizoctonia solani), and Pythium damping off (various Pythium species). Field surveys in Ontario dry bean fields have shown that Fusarium spp. is the most prevalent cause of root rot. Roots are constantly exchanging water, sugars and gases with surrounding soil. Damaged roots release more of these substances (leaky) into the soil, which attract root rot pathogens. Root stressed plants may often resemble nutrient deficiencies, herbicide injury or other stresses. Stunting, overall poor growth, yellowing of leaves, and wilting are symptoms of root rot.