Crown Rot Summary

The diseases are caused by several fungi that can invade a wide range of cereals and grasses, and can survive and multiply on many crop residues, all producing similar symptoms. The diseases produce localized losses by thinning stands and decreasing the number of tillers and by reducing head size and grain weight due to premature ripening. Rotation, plowing in residues, and management practices (late seeding with appropriate seeding and fertilizer rates) help reduce disease incidence. Symptoms Foot and root rots impact winter wheat by reducing plant stand, number of tillers and ultimately yield, and like Take-All, are found in localized patches. Infected plants are first noticed by their stunted appearance. Later in the season plants turn yellow and die. Figure 1. Foot and root rot lesions on wheat seedlings. APS Digital Image. Main symptoms are crown and root browning and rot, and discoloration (not-black) of the lower culm (Figure 1). In late spring, plants under water stress ripen prematurely, producing small white heads. Symptoms are usually more acute on ridges and slopes where soil is dryer. Other symptoms are seed rot and seedling blight. Roots of diseased seedlings are light-brown and appear soaked with water (Figure 1). Eventually the roots and foot are covered by a pink or grey to brown mycelia. Severe root damage is reflected in chlorotic leaves, stunting, and eventually seedling death. Figure 2. Leaf spots caused by Bipolaris on wheat. APS Digital Image. Under wet weather, leaf lesions may appear, primarily on lower leaves. Leaf lesions would be elongated dark brown-black if Bipolaris caused (Figure 2), or brown or ash-colored if Fusarium caused