January 13, 2006 | By: Laura Skillman
PRINCETON, Ky.

For years stripe rust was considered a disease that impacted wheat mostly in the Pacific Northwest. But as the disease has begun to migrate, farmers in some areas of Kentucky are seeing it impact their operations. 

At the recent University of Kentucky annual winter wheat meeting, Plant Pathologist Don Hershman said stripe rust has been found in the state for the past few years, with 2004-05 seeing the largest incidence. Although it had little impact on the crop, as the record 68 bushels per acre state average can attest, Hershman noted that its presence prompted him to present a program on the disease for the first time in his 21 years with the university.

Plants susceptible to stripe rust can die if infected, and the disease can overwinter in Kentucky fields especially if weather conditions are right, making for hot spots within fields. It can affect nearly all parts of the plant.

“I think unless something happens, we are going to have some rust overwinter in Kentucky because it just hasn’t been cold enough,” he said. 

The good news is that there are a large percentage of soft red winter wheat varieties that are resistant to stripe rust. With it added to Kentucky’s list of potential diseases, it is important that producers look for resistant varieties. UK’s wheat variety trials include this information along with yield data and other information growers may want to use to select a variety for their operation.

If for some reason, a producer chooses to use a susceptible variety, the disease can be controlled with fungicides. But timely applications are vital, Hershman said.

“You can’t let the disease get too far in front of you or the fungicide won’t be very good in controlling it,” he said. “So, scouting is very important, and scouting these hot spots in the spring is particularly important because if they get too far along then you could have significant infection.” 

Kentucky and other areas of the country are seeing the disease today because it has migrated down the west coast and into Mexico and some southern states where it now also overwinters. This allows spores to move into many areas across the country. In addition, new races of the disease have developed that have a shorter latent period and are more tolerate to higher temperatures.

“This is why we are seeing it in Kentucky and likely to see it in other places as well,” Hershman said. “There are now huge areas where stripe rust could be a potential problem.”

Hershman said he expects stripe rust will be an issue next year. 

“It is certainly in your best interest to really focus on the information you can get out of the variety testing publication,” he said. “It looks like resistance is the way to go, but if push comes to shove, we do have fungicides that are available to make the applications and do a good job.”

Check with the local county Extension office for variety testing information.

Contact: 

Don Hershman, (270) 365-7541 ext. 215