Seeing Signs of Goss' Wilt in Latham Country

Guest Blogged by John Toft
CCA, Tekemah, NE

Symptoms of Goss’ Wilt were reported earlier this growing season in Nebraska and Iowa.  With all of the storm damage in these areas, including hail and straight-line winds, it’s no wonder that we’re receiving even more reports now of Goss’ Wilt.  Stalk bruising and leaf shredding provide ways for pathogens to enter the corn plant.  High night-time temperatures, which we’ve also experienced recently, favor the spread of Goss’ Wilt.

Goss’ Wilt causes large lesions that start on the leave’s margins and eventually encompass the entire leaf.  These lesions look very similar to Gray Leaf Spot injury.  One simple, but not fool-proof, way to diagnose the difference is that Goss’ will have a waxy appearance due to the different

Note the waxy, shiny appearance to the lesions caused by Goss' Wilt

pathogens that cause the disease.  Gray Leaf Spot is caused by a fungus while Goss’ is caused by a bacterium, which means Goss’ Wilt cannot be controlled by a fungicide.  Effective control measures include crop rotation, tillage and hybrids that show genetic resistance.  Latham’s 2012 lineup has a number of hybrids with excellent disease packages, so keep this in mind as you make your seed decisions in the coming months.

The bacterium responsible for Goss’ Wilt may infect the xylem, or water-conducting tissues of the plant, which results in wilting and death.

Seed selection is most likely going to play an even more important role as Goss’ Wilt becomes more prevalent.  Bacterial wilt was first reported in Nebraska more than 40 years ago, and the list of states affected keeps growing.  Goss’ Wilt has been identified in Kansas, Colorado, Wyoming, South Dakota and Iowa.  The disease has also been confirmed in Illinois and Wisconsin, according to a NebGuide article, “Goss’s Bacterial Wilt and Leaf Blight of Corn,” published by the University of Nebraska—Lincoln Extension.