Background:

Goss’s Wilt is caused by the bacteria Clavibacter nebraskensis, which infects the leaves at any stage of growth. This disease leads to significant yield loss, typically occurring in the vegetative growth stages. Susceptible hybrids, reduced tillage and continuous corn-on-corn fields create favorable conditions for outbreaks of wilt.

This disease develops well in warm weather (80°F and higher). Very hot  conditions above 95 °F  and cooler conditons below 70 °F may delay its development. Goss’s Wilt causes lesions that are long, gray-green to black, water-soaked, and have wavy edges with freckled streaks. Bacterial exudate will ooze out of the freckles. As this ooze dries, it will leave crystalline deposits on the leaves. As the lesions age, they gradually lose the gray-green color and fade to a tan. The plant’s vascular tissue will discolor, you’ll see wet, slimy stalk rot, and leaves will wilt as if drought stressed.

Life Cycle:

The bacterium overwinters in infected corn residue. It spreads through splashing water and fine airborne particles. The bacterium enters the plant through areas that are wounded from hail, blown soil or wind. Symptoms are most visible and severe after silking (R1). Goss’s Wilt can spread in short distances within the same field by contacting leaves on adjacent plants. It can also travel to other fields across country roads during the growing season.

Scouting:

When scouting for Goss’s Wilt, find out if there is history of the disease in the field. Then focus on plants that were injured by weather during the growing season and be on the lookout for freckling and ooze from lesions.

Management: