Fusarium root, crown, and foot rot of wheat
Fusarium root, crown, and foot rot is caused by several Fusarium spp. The disease is widespread and can be found in all wheat production regions of the U.S. and Canada. Seedling blight occurs when Fusarium-infected seed is sown. Infected seedlings tend to be reddish with poor vigor and poor tiller production. Root, crown, and foot rot symptoms include dark brown lesions on primary and secondary roots. A dark brown to red lesion will be apparent near the first node of the wheat plant. Under humid conditions, the interior of infected crowns will be spongy and heavily decayed. Pink, cottony fungal growth may be evident inside lower portions of infected stems. Infected plants may die prematurely, resulting in white heads. If heads survive, seed will likely be shriveled. Symptoms can be observed from tillering through ripening.
Seedling blight is favored when seed is sown into dry, warm (68-86°F) soil. Dry weather typically favors Fusarium root, crown, and foot rot, but infection can occur under a wide range of environmental conditions.
When available, use less susceptible varieties.Planting into a prepared seedbed with available moisture will reduce stress and disease risk. Depending on the causal Fusarium species, an extended rotation away from a small grain crops reduces risk. Fungicide seed treatments can be used for early season protection against seedling blight and root rot. However, the causal pathogen can infect after fungicide seed treatment protection wears out.
Gallery images: J. Marshall and M. Burrows.