Gibberella stalk rot
Area of impact: Stalk
Description: The inner stalk can deteriorate leaving only reddish vascular bundles. Small black specks that can be scraped with a fingernail will be seen on the stalk surface.
Pathogen involved: Gibberella zeae (a fungus)
Timing/Conditions: Infection occurs after pollination during warm wet weather.
Contributing factors: Insect injury and plant stress increase risk of infection.
Management practices: Plant resistant hybrids, maintain fertility, plant proper population numbers, reduce plant stress and control stalk-boring insects.