Trials focus on improving double-crop system

BLOOMINGTON, Ill. — A wheat-double-crop-soybean combination is a common practice in some areas of Illinois, particularly in the southern part of the state, but it can present production challenges.

Eighty percent of the Land of Lincoln’s winter wheat acres are followed by double-crop soybeans, giving Illinois the distinction as one of the top states utilizing the practice.

However, achieving that fine line of both optimum soybean and winter wheat yields in a double-crop system is challenging, to say the least.

A research project, funded by the Illinois Soybean Association checkoff program, is seeking to identify high-yielding winter wheat varieties that can be harvested earlier and allow earlier planted double-crop soybeans to maximize soybean yield potential.

The end result will provide farmers with more data on both available and experimental winter wheat varieties, including answering questions.

When do winter wheat varieties suited to Illinois break winter dormancy? When do they reach maturity, or 14% grain moisture, and are ready for harvest? What are average yield expectations?

Jessica Rutkoski, University of Illinois assistant professor, is leading this project. The research team also includes Luis Gehrke and Tadele Kamssa, research specialists, along with Sophia Arista, a master’s student, all from UIUC.

Trial locations are St. Peter, Urbana, Neoga, Addieville and Belleville.

“We know that every day that the soybean planting is delayed in double-crop soybeans, we lose about one-half bushel an acre, depending on the exact timing, the year and other factors,” Rutkoski said in an ISA ILSoyAdvisor presentation.

“This project is going to help us provide information to farmers on varieties and specifically about how early do they break dormancy, and is there variation in how quickly they dry — are some varieties faster drying than others?

“There are a couple traits that we’re looking at to try to help us do that. We’re trying to find varieties that will dry faster when they reach physiological maturity. When the grain-filling stops, we want them to dry down quickly because after that we’re just waiting, we’re not gaining any additional yield. We want that period to be faster, and that could be one way to save time.

“Then on the other side, we want the wheat varieties not to break dormancy too soon in winter and early spring because then they become vulnerable to spring freeze damage.”

Variety Trials Data

Once the results are collected, the data will be summarized in U of I’s wheat variety trials.

“We’re going to have the data like we normally do on yield in the trials. In addition to that, we’ll have a spring freeze risk score and we’ll also have some results on the timing of physiological maturity and then the timing when they reach 14% moisture,” Rutkoski said.

“Another thing we hope is that by providing this data on the variety trials, we’ll have some uniformity in how varieties are being assessed in terms of their maturity and phenology because it can be very different how different companies refer to their varieties.

“So, by doing it uniformly in an experimental trial, we hope we can develop a source that we’ll be able to compare across multiple different companies.”