It sounds a little odd, but plant pathologists like Bob Harveson are generally disappointed when a growing season doesn’t exhibit a ton of crop disease activity.

Harveson, who is a Nebraska Extension plant pathologist with statewide duties specializing in diseases on specialty crops, is based at Panhandle Research, Extension and Education Center (PREEC) in Scottsbluff.

He researches diseases in prominent Panhandle crops such as sugarbeets, dry edible beans, sunflowers, proso millet, grass seed and potatoes — along with emerging pulse crops like chickpeas, chicory and cowpeas, as well as soybeans and wheat. Plus, he literally wrote the book on plant pathology, publishing “A Century of Plant Pathology in Nebraska” in 2020.

Low pressure

Last season, with extreme drought across western Nebraska and the High Plains — when even a hailstorm would have been welcome for the moisture it could contain — was boring for Harveson, and naturally occurring disease pressure on crops was minimal.

“It didn’t work very well for us in some of our trials, even though we did inoculate some of the plots,” he says. “Where we inoculated for root rot in our potato trials, we obtained some good research. But in general, where we didn’t inoculate, there was no disease pressure.”

Harveson says it was the same way for growers last season. “But for plot work, we tinker with it to get what we want for disease pressure so we can study it,” he adds. “We do what you aren’t supposed to do, so we can get diseases to evaluate what we want for treatments.”

Crops and research

Below are just a few of the specialty crops Harveson and the UNL team at PREEC are working on this season. Many of these trials have been ongoing for some time, and researchers continue to study treatments for varied diseases on different crops:

Pulse crops. Including cowpeas, this is an increasing area of study, Harveson says. “These projects are similar to what we’ve done with dry beans, studying whether the same products will work to curb diseases on other pulses,” he explains. “We assume the answer is ‘yes,’ but I want to determine myself, so I can feel more comfortable in my recommendations.”

With black-eyed peas or cowpeas, like with dry beans, the bacterial diseases are more problematic. “We are testing products that could work for fungal or bacterial diseases,” Harveson notes. “We are also looking at copper alternatives, and that has been our focus for the last five years.”

The problem from a research standpoint, which is a positive if you are a grower, has been a lack of disease pressure year to year, he adds.

Chickpeas. “We’ve been studying chickpeas for more than 20 years,” Harveson says. “For a while, it fell off, but there are companies now that want us to test various products. We’re also studying two different planting times, studying timing of planting and population.”

Researchers are observing more disease likelihood with a second later planting, but early plantings do not have the same yield.

Sugarbeets. A few years ago, there was a lot of research on rhizomania, a virus disease caused by beet necrotic yellow vein virus, but Harveson says that genetic improvements have nearly wiped the disease out.

“We are still doing trials on Cercospora leaf spot, which is always a potential issue. We don’t have as many problems here as in Colorado or in the Red River Valley because more humid areas are more problematic,” Harveson explains. “It’s out there, often in certain areas of a field up against a tree line, but it hasn’t been as big of a problem. We still do forecasting for the disease based on humidity, canopy and temperature. In general, it is a problem to monitor from mid-July through August.”

Sunflowers. Working with colleagues in North Dakota and South Dakota, researchers were granted funding from the National Sunflower Association to do studies in three different locations, covering areas where there is more humidity and other more arid regions.

“We’ve been studying rust, Phomopsis steam canker and Rhizopus head rot,” Harveson says. All three are fungal-related diseases.

Potatoes. Researchers are studying treatments for potato late blight and rhizoctonia disease.

Learn more about Harveson’s research by emailing [email protected].