Symptoms and Signs
Corn plants with Fusarium stalk rot exhibit rotting of the roots, plant base, and lower internodes. The rot normally begins soon after pollination and becomes more severe as the plant matures. The lower stem becomes soft and eventually collapses. The pith inside the stems becomes tan to pink and disintegrates, leaving the vascular strands intact.
Comments on the Disease
The fungus is ubiquitous in a corn field and colonizes the surfaces of all corn tissue but does no damage until the plants are near maturity. Stress and injury to plants seem to favor infection. This is the most common stalk rot in California.
Management
Optimal cultural practices (balanced fertility, good water management, crop rotation, plowing crop residues under, etc.) will help to prevent this disease. Some hybrids are more resistant than others. There are no registered fungicides for this disease.