Plant breeders can select for a myriad of different traits, from grain qualities like low protein or high-test weight to innate resistance against particular pests and diseases. Unfortunately, funding for breeding during the 20th century and into the 21st was slowly funneled into a narrower and narrower set of crops, leaving Iowa and other Midwest states with few or no breeders of small grains.

This lack of research and development of small-grain varieties translates to real risks and costs to farmers. Less disease-resistant small-grain varieties may require more fungicides. Lower-yielding varieties cut into revenue. And certain grain specifications, like test weight in oats, can slam the doors to the more lucrative markets for food-grade products.

To address this gap, Practical Farmers of Iowa has been testing oat varieties at three Iowa locations since 2015 — adding a fourth spot in 2018 — to equip farmers with better data to estimate how varieties will perform on their farm. In 2018, PFI launched a project to organize small-grain breeders throughout the Midwest and build a new tool to predict the best-yielding varieties based on a farmer’s ZIP code.

5 years of oat variety trials

From 2015 to 2019, all trials were conducted on Iowa State University research farms at Kanawha (northern Iowa) and Nashua (northeast Iowa), as well as on one PFI farm location. Starting in 2018, PFI expanded the oat variety trials to an ISU farm at Boone in central Iowa.

Results of these variety trials are published as research reports on PFI's website each year and are a resource for farmers who want to select the right small-grain variety for their operation and goals. Wayne Koehler, a PFI member and farmer near Charles City, has hosted one of the trial sites. “A major component of the variety selection decision for me is: What is the intended use of the oats? Why am I producing them?” he says.

Oats can be used for livestock feed (as hay or grain), as bedding (straw), as a nurse crop for alfalfa and for milling or food-grade markets. They can be grown for seed. “Over the years, I’ve grown oats for all of these different reasons,” Koehler says, “so the market identification is important.” 

If your end use for the grain is livestock feed, you probably want the biggest yield possible, whereas if you’ll take oatlage or oat hay, you might want to look at plant height as an indicator of potential tonnage. “If you’re in an area with a miller or processor for food-grade [oats], then test weight becomes a higher priority,” Koehler says. “Other times, I have seed contracts, where I grow oats for seed. Then it’s more of whoever you’re growing the seed for will determine the variety.”

This past year Koehler grew certified Natty oats. He grew this variety for a cover crop seed business. When growing oats for seed, special care must be taken, as the vast majority of oat varieties have legal restrictions on the conditions under which they can be marketed as seed.

Variety trial results helpful

Variety trial results can also give farmers clues as to how to manage the crop in Iowa soils and high-moisture climate. At the Nashua research location, an ongoing fungicide trial shows the response, and thus the return on investment, of fungicide applications to key varieties.

In 2019, researchers conducted the fungicide trial on four varieties (Deon, Hayden, Horsepower and Shelby 427) and showed that a fungicide application on Hayden and Horsepower statistically increased yield and test weight, but not with Deon and Shelby 427. This is likely due to Deon and Shelby 427’s innate disease resistance — their genetics render them resistant or moderately resistant to more diseases.

VARIETY TRIALS: Lucia Gutierrez researches oats, wheat and barley varieties at the University of Wisconsin and is developing a variety selection model that farmers can use to choose varieties best-suited for their specific location. 

The results show that growers who wish to avoid fungicide applications can do so without sacrificing yield by selecting more highly resistant varieties. Another perk: These varieties are easier to manage. “Pay attention to disease resistance and tolerance ratings,” Koehler says. “It helps give you an indication of how closely you might have to manage the crop as far as scouting for disease, and the likelihood of whether you may or may not need to apply fungicides.”

It’s important, however, to recognize the limits of variety trial data. While they can empower you to make educated guesses about how the season will go, the locations where the research was conducted all have different soils and weather, and use different tools to manage their systems.

“The variety trial yields were lower than my own oats were this past year, in 2019,” Koehler says. “My own oats were able to get drilled earlier than the trial plot was — at least a week earlier. I no-tilled my oats, which gained me a day or two because I didn’t have to wait for it to be dry enough to do a tillage pass.” By contrast, the trial plots were planted with a standard drill, so a pass of soil finishing was conducted on the day of or prior to oat planting.

Selector tool leverages trial data

The phenomenon of spotting differences between the same varieties at different locations and seeing the top-yielding varieties shuffle at each site, has a technical term: genotype by environment interaction. Lucia Gutierrez, associate professor in the agronomy department at University of Wisconsin-Madison, researches these interactions and breeds oats, wheat and barley.

“A genotype by environment interaction means that if we have two varieties and we grow them in two different environments, the best variety might be different in each environment,” Gutierrez explains. “Small grains, particularly, have a large genotype by environment interaction, so one variety is not going to work for the whole U.S.”

One area of Gutierrez’s research addresses this gap in field data by developing models that can predict very localized small-grain variety performance. In 2018, PFI organized a team of researchers to develop one such model that would help farmers better predict the top-performing variety for their location, even if there wasn’t a variety trial location nearby.

Tool to be on PFI website

Gutierrez’s lab will use oat and wheat variety trial data provided by researchers in six states throughout the Midwest to build a statistical model that will classify a farmer’s location as a certain “mega-environment.” The model will take into account topography, soils, climate and other factors, and then access the data from the variety trials conducted in the most similar mega-environment to predict oat and wheat variety performance in that farmer’s location.

“With only three or four variety trial locations in Iowa, we don’t know if a farmer’s location will perform like the one they’re closest to or the one farther away that has more similar soil or terrain, for example,” Gutierrez says.

Eventually, the model will be publicly accessible on the PFI website, where any farmer in the coverage area will be able to enter their ZIP code, their crop (oats or wheat) and their end market to generate the model results for themselves. But first, the model’s predictions will need to be tested on farms.

If you’re interested in getting involved as a trial location for the selector tool for winter wheat or using the tool and providing feedback on it, contact this writer, Alisha Bower, at 515-232-5661 or [email protected].

Bower is PFI’s strategic initiatives manager.

Source: PFI, which is solely responsible for the information provided and is wholly owned by the source. Informa Business Media and all its subsidiaries are not responsible for any of the content in this information asset.