Cochliobolus sativus root rot

(C. Sativus, Fusarium spp.)

Common Root Rot is caused by C. Sativus and produce identical symptoms to the Fusarium organism. Infected plants are usually scattered throughout fields rather than in patches and often go unnoticed. Severely infected plants ripen prematurely and “stickout” in green stands. Root development is reduced and plants are easy to pull out of the soil. Lower stems, leaf sheaths, culm, crown, roots and subcrown internode have brown lesions. The result is a reduced number of heads, reduced seed size and reduced number of seeds.

Scouting

Test seed. Scout stand establishment early in the season throughout the field, looking for patches of missing plants. In later stages of emergence, scout for patches of infected plants and check specifically for brown lesions on the coleoptile, especially in hot dry weather. On more mature plants, symptoms appear on tissues near or below the soil surface that will extend up through higher plant parts as the disease progresses. Dig up plants to see if root development has been damaged.

Control

No resistant cultivars. Use healthy seed and practice crop rotation. Both Raxil T and Vitaflo 280 seed treatments will protect against C. Sativus and Fusarium that attacks seeds and seedlings.