Wheat studies focus on high yields, early maturity

CHAMPAIGN, Ill. — Research is underway at the University of Illinois to develop high-yielding wheat varieties with early maturity enabling earlier planting of double-crop soybeans.

Jessica Rutkoski, U of I assistant professor, small grains breeder and winter wheat breeding program lead, detailed the efforts during the recent Illinois Soybean Association Field Advisor Forum.

The work is among 22 soybean production research projects for 2024-2025 funding by the soybean checkoff. Many of the projects span multiple years to more fully understand and address critical issues affecting the future of Illinois soybean production.

The project provides jointing time, maturity time and yield data for available winter wheat varieties to Illinois farmers so they can make more informed decisions about which varieties to incorporate into a double-crop rotation.

The research is also developing the next-generation wheat varieties that will help growers reach higher yields on both wheat and double-crop soybean crops.

Rutkoski’s work includes improving wheat production with a focus on double-crop profitability since 80% of Illinois’ wheat is grown ahead of soybeans.

“I work on developing elite early maturing wheat varieties and also helping private companies identify varieties among their germplasm that are also high-yielding and early maturing. So, we have our own breeding program. We also help private company breeding programs get the data they need to make those decisions,” she said.

“We also provide official performance data on wheat with the Variety Testing program, providing all of the important agronomic traits, as well as maturity time so that we can get better standardization of when these varieties mature.

“Different companies have different scales. They call things by different names. It’s not quite like soybean varieties with the numbering system. Wheat varieties don’t really have that. We’re providing that standardized data so that you can really compare apples to apples across a bunch of different companies and their varieties.”

Other research includes identifying wheat varieties that lose moisture quicker.

“We think there may be variation in that as a trait, so that may be able to help us improve yield and get early varieties because usually there is a trade-off. Earlier varieties would tend to be lower yielding, so we’re always looking for ways to break that,” Rutkoski said.

U of I’s Variety Testing program provides unbiased data on wheat varieties released in the state. The data is available online, providing yields across locations, test weight and scab resistance. A new feature is the maturity time and jointing time for various varieties.

“Maturity time is critical because with double-crop soybeans, the sooner you can harvest wheat, the earlier you can plant soybeans. You lose half a bushel of soybean yield per day the later you plant. Earlier maturity wheat means planting the soybeans earlier and better soybean yields,” Rutkoski said.

Jointing Timing

Noting the stages of development for wheat, she said a critical stage which happens usually in March is jointing. That is when the wheat becomes vulnerable to a freeze.

Temperatures below 26 degrees will cause damage to the crop.

“We don’t want jointing too early because then it will be vulnerable to freeze. When we’re trying to select for early maturity, we sometimes get earlier jointing and that’s bad. We don’t want that,” Rutkoski said.

“We want to identify earlier varieties that don’t joint early. That’s why we’re presenting this information and evaluating it.”

The data provided in the Variety Testing program includes early, middle or late jointing time, as well as maturity date.

“If you’re looking for an early variety of wheat for your double-crop soybeans, you want early maturity, but you do not want early jointing. You want normal or late jointing,” Rutkoski said.

“Last year was the perfect storm for getting freeze damage in wheat. We did find some plots that got completely damaged by spring freeze. The frost damages the stem and it will cause sterility.”

Rutkoski provided the following recommendations on early wheat varieties:

• Consider yield and maturity time together because maybe it’ll be very early and you’ll gain soybean yield from planting earlier, but if the wheat yield is too low that will not help in terms of profitability.

• Avoid the varieties that joint early.

• Remember, the other important traits — test weight, scab resistance — all those other things still matter.