Fungus spores can remain in the soil and crop residue for five years or more. The spores germinate, invade the roots and cause localized infections. New spores are produced in infected plant parts. Browning root rot is found in wet soils that have low phosphorus and organic matter levels and a previous history of cereal crops. This disease occurs in patches.
Infected plants become pale green, and lower leaves turn yellow and then brown.
Plants are slightly stunted. Diseased plants have fewer tillers, poor root growth and delayed maturity. Soft, wet brown lesions develop on the younger roots near their tips. Infection during autumn or spring can kill young seedlings, but late season infection usually causes a temporary setback, which may not significantly affect yield. A few isolated diseased areas in a field may be a warning sign of low amounts of organic matter and low phosphorous availability.