Tackling SCN, RKN, Phytophthora and Stink Bugs in Missouri Soybeans
Missouri soybean farmers face increasing pressure from pests and diseases, but researchers like Feng Lin, assistant professor of soybean breeding and genetics at the University of Missouri, are working hard to stay ahead. Lin’s team collaborates closely with the Missouri Soybean Merchandising Council (MSMC) to ensure their breeding efforts directly address farmers’ needs.
Targeting Top Disease Threats
Lin’s breeding program focuses on stacking disease resistance genes into new soybean varieties, with a special emphasis on soybean cyst nematode (SCN) and root-knot nematode (RKN), the two biggest threats to Missouri growers.
“Soybean cyst nematode is absolutely one of the top concerns, along with root-knot nematode,” Lin says. “We work with researchers nationwide to integrate resistance genes into our breeding lines. We don’t want to lose the genetic resources developed before us; we want to keep them and incorporate new resistance sources.”
Phytophthora root rot is another growing issue in Missouri.
“Phytophthora can cause problems at multiple growth stages,” Lin says. “If conditions are wet, you might see poor germination because seeds rot in the soil. Even if seedlings emerge, they can become stunted or die. Later in the season, infected plants turn yellow, wilt and eventually die.”
Farmers looking to evaluate the latest soybean varieties for disease resistance and yield performance can explore Missouri’s Soybean Variety Testing Program for research-backed comparisons: varietytesting.missouri.edu/soybean.
The University of Missouri’s Soybean Performance Tests, conducted at the Fisher Delta Research and Education Center in Portageville, have played a key role in providing growers with unbiased, up-to-date variety comparisons since 1973. Over time, the number of soybean entries in the testing program has grown from 51 in its first year to over 400 by 2012, making it one of the most comprehensive evaluations in the region.
“With so many soybean varieties on the market, selection can be difficult,” Lin says. “That’s why it’s critical for growers to have reliable, research-based performance data to compare varieties before making planting decisions.”
A Stinky Rising Threat
While diseases remain a major concern, Lin is also investigating the genetics behind stink bug resistance, a problem that has escalated in Missouri fields.
“Last year, we observed a lot of stink bugs in our fields,” Lin says. “They damage soybean plants by sucking out nutrients from leaves and pods. Unfortunately, we don’t yet have known
genetic resistance, but we’ve identified some varieties that seem to tolerate stink bugs better than others. Our goal is to find the genes responsible for this tolerance.”
To tackle this, Lin is working scientists and entomologists at Louisiana State University and Mizzou to screen breeding lines for natural resistance.
“We’re excited about this project,” Lin says. “Once we gather more data, we can use genetic markers to incorporate resistance directly into new soybean varieties.”
Connecting Research to the Farm
One key strength of Missouri’s soybean breeding program is its close relationship with farmers. MSMC serves as a bridge between researchers and growers.
“Missouri has done an exceptional job ensuring research directly benefits farmers,” Lin says. “The Missouri Soybean Merchandising Council connects us with growers, gathers their concerns and funds research to address them. It’s a two-way relationship.”
To help bring research from the lab to the farm, Missouri’s Foundation Seed Program plays a crucial role.
“Each year, our breeding program releases new varieties, but we start with very limited seed stock, maybe 50 pounds, which isn’t enough for farmers,” Lin says. “Foundation Seeds increases that supply so growers can purchase directly.”
See the Research Firsthand
Missouri soybean farmers will have a chance to see these efforts in action during the 2025 Field Day, scheduled for August 5-6 at the Fisher Delta Research Extension and Education Center in Portageville.
“At Field Day, farmers can visit our plots, talk to researchers and see firsthand how our breeding lines perform,” Lin says. “It’s a great opportunity to connect research with real-world farming challenges.”
Moving Forward
While traditional breeding can take six to seven years to bring a new resistant variety to market, advancements in genetic marker selection are helping speed up the process.
“If we already have resistance traits in our breeding pipeline, we can move quickly,” Lin says. “But if we need to introduce resistance from outside sources, it takes time. Thankfully, genomic selection and marker-assisted breeding help shorten the timeline to about five or six years.”
With continued collaboration between farmers, researchers and industry partners, Missouri soybean growers can expect more resilient and high-performing soybean varieties in the future.
This article is paid for in part by the United Soybean Board.