Infection usually attacks patches of plants that become stunted. Roots of affected plants are dark brown to black because of fungal invasion. As the plant matures, its roots become rotten and brittle until the plant can be easily pulled from the soil. Barley, triticale, and rye are all susceptible to take-all root rot. In order of susceptibility, wheat is most susceptible, followed by barley, oats, triticale, and rye, which is least susceptible.
Crop rotation is the best control for take-all root rot.
Care must be taken to eliminate all grass species from the rotation, because the fungus can survive on a variety of grass species. Other control measures include the use of nitrogen fertilizer in the ammoniacal form, particularly in areas where the soil pH is acidic, to lessen the disease. Nitrogen in the nitrate form may increase the severity of the disease. Common Root Rot And Seedling Blight Common root rot is caused by one or more fungi. Depending on the location, fungal pathogens associated with diseases of root and crown tissue include Cochliobolus sativus, Fusarium culmorum, and F. graminearum.