The fungus interferes with water uptake.
Warm weather favours the disease.
The fungus persists in the soil, while the mycelia and spores survive for many years in flax debris and other organic tissue. Spores dispersed by wind and rain spread the fungus from one field to another. Symptoms of Damage Seedlings may be killed shortly after emergence. Delayed infections cause yellowing and wilting of leaves, followed by browning and death of the plant. The roots of dead plants appear ash-grey.