The 2006 crop is still in the field, but farmers are already being cautioned to be on the lookout for Stewart’s wilt in 2007 crops, after reports of the disease in Michigan field corn surfaced during August and September.    

Plantings should be checked for flea beetle infestation early in the 2007 crop season.

 “We want growers to be aware that we did find Stewart’s wilt in field corn this year, and we recommend that they keep their eyes open for corn flea beetles (carriers of the disease) early next spring,” said Diane Brown-Rytlewski, a Michigan State University (MSU) Extension field crops pathologist.  “It could be a fluke that doesn’t recur, but we want people to be aware that it could occur next year.”

Seed corn inbreds and sweet corn are the usual targets of Stewart’s wilt. The bacteria is transmitted to corn plants by infected corn flea beetles as they feed upon corn plants.  Upon infection, bacteria invade the plant’s water-conducting tissue, causing heavy damage to leaves and stalks.

Whether or not field corn is affected next year will depend greatly on the weather, Brown-Rytlewski said. 

“If we have a harsh winter and the beetles carrying the disease aren’t able to survive, then it’s unlikely that next year’s crop will be harmed,” she said.  “But, if we have a mild winter, there could be far greater repercussions.” 

A fact sheet about Stewart’s wilt in Michigan corn can be found on the MSU Extension Web site at www.msue.msu.edu.