Goss's Wilt (photo courtesy Iowa State University)

 

 

Corn growers in some parts of southern Manitoba are having to change varieties to manage the impact of Goss's Wilt.

The new disease was found in 87 out of 240 fields in a survey conducted by Pioneer Hi-Bred last summer.

"In the majority of the fields, the impact was not very dramatic, maybe a bushel or two. In about a third of the fields there was what I would consider a minor yield impact of 5, 10 or maybe 15 bushels. However, in 20 percent of the fields, there was severe infection and yield losses of up to 40 bushels per acre," says Pioneer Hi-Bred agronomist Wilt Billing. "Where we did find higher infection rates, hail or heavy winds had been very prevalent during the growing season."

He says stubble removal and hybrid selection are the main tools for managing Goss's.

"Specific hybrids are showing promise and showing more resistance to Goss's," he says. "If the disease does show up in your fields, you have to be prepared to manage it differently. However, none of these things will get rid of the disease so it's something growers will just have to manage going forward."

He notes weed control is also important as green foxtail and barnyard grass are hosts for the disease.

Producers should also take measures similar to what's being done by canola growers in Alberta to minimize spread of clubroot disease.

"The bacteria will spread on equipment and clothing. So if you know you're in an infected field, disinfecting your equipment and changing your clothes before moving into a new area will help reduce spread of the disease," he says.

Despite the serious concerns about the disease, Billing is confident producers will learn to manage Goss's Wilt.

"I don't see it hurting corn acres. Growers in Nebraska have been dealing with this disease for over 35 years and have managed the disease quite effectively, so I don't see it having a negative effect on corn acres in Manitoba. It's just another thing for producers to consider when selecting hybrids," he says.

Goss's was first found in Manitoba in the Roland area in 2009. Yields were reduced by 30 to 50 bushels per acre in the first few cases. A Goss's infection is characterized by lesions that are grayish in the centre with a pale yellowish colour along the edge where the bacteria are active.

~ Tuesday, March 8, 2011 ~