Throughout most of the midwestern US corn belt, a disease called Goss’s Wilt can be found reducing corn yields by much as 30%.  In recent years, Goss’s Wilt has been found as far east as western Michigan and has been moving east.  The behaviour and management of Goss’s Wilt is much different to how growers typically manage diseases.  

Goss’s Wilt (Clavibacter michiganensis subsp. nebraskensis) is caused by bacteria which enters the plant through an open wound.  Symptoms can often be confused with drought stress, fungal or viral infections or chemical burn.  There are two phases of the disease.  The first phase is leaf blight where the bacteria cause lesions on the leaf.  The second phase is systemic wilt where the bacteria disrupt the nutrient flow within the stalk.  The leaf blight phase is more commonly identified and damaging to yield.  Leaf blight lesions of Goss’s Wilt look very similar to Northern Corn Leaf Blight however, the shape of the lesions are irregular, are not limited between veins, often appear water soaked and contain black speckles within the lesion.  Reproduction and spread of the disease is primarily on infected residue. 

Crops in a field

In Canada, Goss’s Wilt is only found in southern Manitoba where it is a major concern to many growers.  To manage the disease, growers rely primarily on resistant hybrids, however, incorporation of crop residues, crop rotation and weed management are also effective. 

Maizex Seeds is involved in Goss’s Wilt screening to evaluate corn germplasm.  As part of this screening process corn inbreds and hybrids are inoculated with bacteria collected locally.  The response to the inoculation is evaluated and the information is used to direct future breeding decisions.  Corn germplasm response to inoculum ranges from no infection (Figure A) to wilting of the entire leaf (Figure B). 

Crop leaf growing bacteria

Crop leaf growing bacteria

Planting hybrids resistant to Goss’s Wilt is the primary management tool used by growers.  Identifying and incorporating resistant corn germplasm into corn hybrids ensures that growers planting Maizex hybrids continue to receive top yielding hybrids adapted for their farms. 

Shawn Winter
Product Development Manager

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