Goss' wilt, a corn bacterial disease historically confined to the Great Plains has spread to several states in the Midwest and is moving north and east. According to crop experts at Pioneer Hi-Bred, a DuPont business, the disease has spread across Iowa and into Illinois, as well as southern Wisconsin, Minnesota and the Dakotas. Growers in these states who haven't yet encountered the disease should consider minimizing their risk to Goss' wilt in the coming planting seasons.
"The rampant spread of Goss's wilt can be attributed to wind movement and storm systems that carry tiny particles of crop debris which carry the bacteria," says Scott Heuchelin, Pioneer research scientist and field pathologist. "The disease typically enters the corn plant through wounds caused by rain, wind and hail. Once the bacteria have become part of the soil environment, all they need is a genetically susceptible hybrid and a few wounded plants for the disease to take hold in the field. If a geographic area is infected, the disease will persist year after year, so growers must manage the disease to preserve their yields and ultimately, their profits."
Heuchelin and other Pioneer experts advise growers who encountered this disease in 2011 to select hybrids that are more resistant for 2012.
"Goss' wilt is caused by a bacterium, not a fungus," Heuchelin says. "That's why foliar fungicides commonly used to control fungal corn leaf diseases are ineffective. Because no proven chemical control measures are currently labeled for corn, preventing or avoiding infection is crucial," Heuchelin adds. "Pioneer has conducted decades of research breeding for Goss' wilt resistance in the western Corn Belt and has developed highly resistant germplasm for deployment in environments with high Goss's wilt pressure."
The disease may be transmitted from field to field through equipment or weather that transports infected residue. Harvest and tillage equipment, balers and wind all can carry infected residue and soil to uninfected fields. To help avoid spread of the pathogen, growers should harvest and till infected fields last and clean equipment of crop residue.
Goss' wilt can affect the corn plant by disrupting the vascular system and restricting the movement of water and nutrients throughout the plant. Foliar infections may lead to reduced stalk quality and yield by limiting photosynthesis. The more severe vascular wilt causes stunting, wilting and premature death of plants. Growers can see up to 50% yield loss when susceptible hybrids are infected early in the growing season.
"Growers can help minimize their risk of recurrent outbreaks by using more tillage and crop rotation, but planting a resistant hybrid is by far the most effective way to manage this disease," Heuchelin says.