Fusarium stalk rot of corn
Fusarium stalk rot is caused by multiple fungal pathogens in the Fusarium genus. It is among the most common stalk rots in the Midwest with F. verticillioides the primary causal pathogen. Affected plants have shredded pith that may be a whitish-pink to salmon color and die prematurely. Brown streaks may be observed on the lower internodes.
The fungi overwinter as mycelium in corn residue, other dead plant residue, and in corn seed. This fungus is often found growing in healthy stalks and may cause rot only under certain conditions. Spores are spread by wind and splashing water; infection takes place through the roots, wounds in the stalk, or leaf scars. Disease development is favored by warm temperatures (80–100°F) and when a wet midseason follows early season dry weather.
Resistance to Fusarium stalk rot is available. Rotation and tillage will reduce inoculum. If more than 10 to 15 percent of stalks are observed to be rotted 40 to 60 days after pollination, the field should be scheduled for earliest possible harvest.
Gallery Images: A. Robertson