Goss's Wilt Raises Questions About Hybrid Susceptibility

Strong presence in Illinois and Iowa have Indiana experts paying attention.

Published on: Dec 6, 2011

Has the Goss's wilt organism modified and it is on a march eastward, with Indiana next in its sights. While that may seem like a logical conclusion, experts within Indiana don't think so. Instead, they believe the disease that has caused sporadic problems in western states caused bigger outbreaks in Illinois and Iowa last year because of a serious of severe storms with wind and hail that moved the bacterium causing the disease into areas where it hasn't been before.

If that's the case, it wouldn't be expected to spread outside of where it has already been found in Indiana. That's in the northwestern counties. Popcorn is big there, and popcorn is very susceptible to the disease. It was identified in northwest Indiana in 2008, certainly long before this year.

What is less clear is what handle seed companies have on how susceptible or tolerant their various hybrids are to the disease. If you live in one of the affected counties, or if you're still nervous the disease might spread, you may want to talk to your seedsman about their line-up. They may or may not have a handle on which varieties stand up well to this disease.

A representative from one regional company that operates in Indiana says he doesn't know a lot about susceptibility of the hybrids he sells here because the disease has not been present in his area. Without disease pressure, it's difficult to select for the disease, and to get a handle on how various hybrids would perform if there was significant pressure.

However, Dave Nanda, a crops consultant and director of genetics and technology for Seed Consultants, Inc., says many hybrids sold in Indiana were actually developed elsewhere. Hybrids developed in Iowa or other states to the west have likely been screened for the disease, since it is more prevalent there, even though the outbreak this past season was much stronger than usual.

Nanda is confident that he could make recommendations on hybrids in their line-up that would stand up best to Goss's wilt. He would be relying on observations made as the hybrid was developed in areas where the disease is more prevalent.

Goss's wilt is caused by a bacterium. Fungicides will not be effective against it. The best preventive measures at the moment, experts say, are to plant less susceptible hybrids if your seedsman can identify them, to avoid continuous corn, and to perform enough tillage to remove more residue from the surface. The bacterium overwinters in corn residue.