SHABBONA, Ill. — Although it hasn’t been much of a concern this year, Goss’ wilt can appear at any time during the growing season, said University of Illinois plant pathologist Carl Bradley. He was one of several speakers at a recent field day for the Northern Illinois Agronomy Research Center.

“There have been a couple of positive Goss’ wilt samples submitted to the University of Illinois Plant Clinic so far this year, but I have not heard of any other observations yet this year. I’m a little surprised we have not been seeing more Goss’ wilt, considering some of the heavy thunderstorms that have gone through the area,” he said. “We may still have some more showing up.”

Bradley said there was essentially no problem in 2012. “This was likely due to lack of rainfall, which means that the Goss’ wilt pathogen’s cells likely were not splashed onto the leaves and that it was less likely that the corn leaves were injured by high winds or hail, since the pathogen infects through wounds in the leaves.”

He explained because it’s a bacterial disease, chemical control is not feasible. “There are resistant lines, but there’s really no silver bullet,” Bradley added.

He said some research has been done with copper hydroxide, but “that’s probably not economically feasible.”

Because the plant can be infected at any stage of growth, the earlier it’s infected, the greater the loss of yield. If the plant is infected in early stages, the disease becomes systemic, eventually plugging the xylem vessels in the stalk. In some cases, he said, no ear will be produced.

Bradley said it’s best to scout cornfields early in the morning, before the liquid that oozes out of the damaged areas dries. He said the leaves appear glassy and the liquid resembles maple syrup.

He explained the most effective treatment is residue management, since that is where the bacteria lives. “I’m not advocating bringing out the moldboard plow, but reducing residue should help,” he said.

He also suggested rotating with soybeans and looking for Goss’ wilt-resistant varieties.

In answer to a question from field day attendees, Bradley said there is a slight resemblance between Goss’ wilt and Stewart’s wilt, but the lesions caused by Stewart’s are narrower.

He also touched on white mold in soybeans, in his talk. He said it produces spores that infect the flowers so it should be treated before pod development. Bradley said many fungicides are not effective against white mold, and encouraged reading labels to find a product that specifically lists treating white mold.