Samples Needed Of Goss’s Wilt Of Corn, A New Disease For Michigan

Aug 22, 2014

Samples of Goss’s wilt of corn can be tested for free through a grant from the Corn Marketing Program of Michigan.

Partially resistant corn hybrid on left next to susceptible hybrid on right. All photos in article by Carl Bradley, University of Illinois

Goss’s wilt is a bacterial disease of corn caused by the bacterial pathogen Clavibacter michiganensis subsp. nebraskensis (Cmn). For a long time the disease was restricted to the western states of the Corn Belt. However, more recently the disease has been confirmed in Wisconsin, Illinois, Indiana, Canada and even Louisiana. Over the last couple of years, Goss’s wilt has been found in seed corn production fields in Michigan.

Through a project with the Corn Marketing Program of Michigan, Michigan State University Extension specialists are requesting samples of Goss’s wilt so that we can better understand why this disease is becoming an issue. The symptoms of Goss’s wilt include a leaf blight phase which can look similar to other foliar diseases. Goss’s wilt can be distinguished by water-soaked lesions with freckles around the margin of the lesion. A shiny exudate is also formed on the surface of the infected leaf.

Early leaf lesion

Above, Early Goss’s wilt leaf lesion. Note the freckling around the lesion.Below Established Goss’s wilt lesion. Note the shiny exudate on the leaf surface.

Established lesion

Management of Goss’s wilt relies on accurate identification, which can be difficult. If you suspect Goss’s wilt, submit a sample to the Chilvers lab (chilvers@msu.edu; 517-353-9967) or MSU Diagnostic Services for confirmation. For Goss’s wilt management, the field should be rotated away from corn to help reduce the inoculum load, and grass weeds that can harbor the pathogen should also be controlled.

No corn hybrid is completely resistant to Goss’s wilt, but hybrids do differ in their susceptibility, select hybrids with a high level of partial resistance. As the Goss’s wilt pathogen survives on corn residue, cultivation can help by encouraging breakdown of corn debris.