New Egan wheat strain resistant to orange blossom midge
Posted on 19 January 2016
BOZEMAN - Nine years ago, a tiny orange bug quietly entered northwestern Montana and began demolishing spring wheat yields, costing producers millions of dollars. What was once a primary cash crop for Flathead and Lake counties quickly became an economic disaster and a major worry for area farmers.
In 2007, most producers stopped growing spring wheat and turned to agricultural scientists at the Northwestern Agricultural Research Center, part of the Montana State University Montana Agricultural Experiment Station for help.
Nine years later, Montana Agricultural Experiment Station says that the answer to the major economic threat of the orange blossom wheat midge is a spring wheat variety called Egan. The new variety is resistant to the midge and is now commercially available to producers.
The seed is also the first-ever certified blend released from Montana Agricultural Experiment Station. Egan is so effective in destroying the midge that it requires mixing a small percentage of a susceptible variety with it to keep the midge from developing resistance or becoming a superbug, said Bill Grey, manager for the MSU Montana Foundation Seed Program. This combination of seed is also referred to as “refuge in a bag.” The refuge refers to the non-Egan seed that will attract the midge.
To bring Egan to commercial viability took a team of wheat breeders, entomologists and agronomists, as well as the only gene in the world known to provide resistance to the orange blossom wheat midge, national and international research connections and colleagues and a statewide network of Montana farmers and certified seed growers. It also took relationships and long meetings between MSU research centers, Extension agents and friends at the Montana Department of Agriculture. Above all, it took an understanding of what weaves much of Montana together: that agriculture’s challenges and successes extend far beyond one’s own field.
In 2006, the midge was quickly and easily adapting to the Flathead. So, Bob Stougaard, superintendent of the Northwestern Agricultural Research Center, turned over every rock: He consulted with colleagues in Canada and North Dakota, he researched cropping systems, researched when and what insecticides to spray, then introduced a parasitic wasp to prey on the midge.
“I never experienced anything like this,” Stougaard said. “The capability of the midge to seemingly show up out of nowhere and cause so much devastation to a crop was astounding.”
By 2009, evidence was mounting that the midge was starting to spread across the state. Seeing the devastating potential of the midge, Stougaard, Research Associate Brooke Bohannon, retired Pondera County Extension Agent Dan Picard, MSU entomologist David Weaver and a host of Montana farmers and crop consultants who volunteered to put pheromone traps in their fields began monitoring for the midge. MSU software engineer John Sully brought all the data together and created a live-tracking website, Montana Pestweb, that showed the spread of the midge. Six Montana Agricultural Research Centers and 26 MSU Extension offices worked with growers and crop consultants to place hundreds of traps across the state, Stougaard said. Extension agents trained local producers in the biology of the midge, how to track it, what insecticide was effective and, most importantly, when and when not to spray.
“Scouting and spraying were short-term solutions, and we didn’t know what the future would look like,” Stougaard said.
That’s when producers asked MSU spring wheat breeder Luther Talbert if there was anything MSU’s wheat breeding program could do. Thanks to colleagues at North Dakota State University, Talbert got ahold of the only gene in the world discovered that’s resistant to the midge, called SM1. SM1 produces toxins that kills the midge. When the midge burrows into the developing wheat seed, it dies. Talbert started crossing the resistant line into Montana adapted varieties using traditional breeding techniques.
“We crossed this line with the SM1 gene with varieties that were suitable to northwest Montana and let nature derive progeny lines from that,” Talbert said. “From there, we planted those lines in the fields and selected the ones with characteristics we like.”
Six years later, Egan – named after the Egan slough in the Flathead where the midge was so prevalent – was born. According to Talbert, Egan also has high grain protein, strong yield potential under high-yield conditions and is resistant to stripe-rust, a wheat disease found in Montana that can also limit yields. On the other hand, Egan is a little taller than typical varieties grown under irrigation in the Flathead Valley, so lodging – bending over of the stems -- may occur under very high yield levels, Talbert said.
Because Egan with its SM1 gene is so potent to the midge, Canadian and MSU entomologists suggested it be blended with 10 percent of a non-resistant variety to prevent the midge from developing resistance.
“This gene works so well that it kills nearly every single midge," Talbert said. "But those very few that survive may have a resistance to the SM1 gene that they can pass on to their offspring. As their generations progress, you’ll end up with significant, resistant populations that won’t be stopped by Egan.”
The way to mitigate this problem is to allow a small population of “normal” midges to survive and breed with any potential resistant midges. This is accomplished by blending the Egan seed with seed that is susceptible to the midge population – about 10 percent of the susceptible variety. Growers can choose the susceptible variety to blend Egan with.
“In a way, producers are sacrificing a small portion of their crop so that the susceptible midges continue to persist and we never allow a significant population of resistant midges to develop,” Talbert said. “We’re sort of using nature’s greatest tools against itself, so it’s a natural form of resistance.”
Montana Agricultural Experiment Station has grown and tested Egan at seven research centers across the state. Last spring, Montana Agricultural Experiment Station gave Egan to the Montana Foundation Seed Program for production and certification. Now, Egan is available to producers and is being sold as a certified blend – the first ever certified blend in the university’s history. Purchasing the blend comes with a Certified Seed Only acknowledgement, binding producers to keep buying certified seed year after year, in an effort to ward off a population that is completely resistant.
Grey, who recently retired after 35 years, said the certified seed only and blend idea might take some education on behalf of growers and producers.
“It’s important for all to understand how important the blend ratio is and a bit about the background, as the agreement is legally binding,” he said. “This was a collective response for public good, and the certified seed only agreement is also dependent on a kind of handshake and agreement between neighbors across the state.”
Dan Lake, owner and partner of Lake Seed Inc. in Ronan and certified seed grower, is selling Egan to area growers this spring.
“Our growers are really excited about Egan, and we’re going to blend it with a hard red spring wheat we have,” Lake said. “The entire process to get to this point is an extremely good example of MSU research centers working to identify, find solutions and solve a problem alongside producers. When you have research centers that are fixed, functional and modern, it’s an investment statewide, and this is the kind of result you see.”