Drought and warm weather cause more severe infections. Nutritional stress can also favour infection. Secondary infections by other soil-borne pathogens may mask the initial symptoms. Common root rot is favoured by soil compaction that restricts root growth and by over-applications of nitrogen under moisture stress conditions. Spores may remain viable in soil for several years.
Severe infections can abort tillers.
Early detection is required for proper diagnosis. Pull up plants and examine the crowns and subcrown internodes for disease. Look for brown discolouration of stem bases, roots, crowns, and lower leaf sheaths. Infected plants are generally shorter and produce fewer stems and grains per head. At times, plants appear bleached and dead.