Resistant Wheat Variety Fights Orange Blossom Wheat Midges02/17/2016
There’s a new soldier in the fight against orange blossom wheat midge, a pest that crept into Montana nine years ago and decimated crops in the western side of the state. The pest has been seen in increasing numbers across the state since, including Richland County — although it is not yet the million-dollar economic destroyer that it’s been in Flathead and Lake counties.
North Dakota has also seen populations of the midge come and go on a sporadic basis, making this a pest poised to emerge across the MonDak if something wasn’t done about it, the Williston Herald reported.
The new soldier in the fight is named Egan. It is a resistant wheat variety named after the Egan slough in Flathead, where the midge first became so prevalent.
Wheat growers in Flathead and Lake counties have all but given up on growing spring wheat due to the pest.
In Richland County, Extension Agent Tim Fine monitored fields for the appearance of the pest in the MonDak this summer. Both his traps did catch some adult wheat midge populations, though he hasn’t yet received any reports of significant economic damage due to the pest.
It’s something he will continue to monitor going forward.
Wheat midge may not be a big economic concern in the MonDak yet, but the new variety could nonetheless be helpful as an ounce of prevention in fields where the midge has been spotted, he believes.
Egan was grown at EARC. The yields weren’t stellar, so it wouldn’t be recommended unless a grower is seeing an increasing problem with midges.
Bringing Egan to commercial viability took an extensive team of wheat breeders, entomologists and agronomists, as well as national and international research connections and a statewide network of Montana farmers and certified seed growers.
In 2006, it seemed like they were losing the war, however. The midge was quickly and easily adapting to Flathead. Bob Stougaard, superintendent of the Northwestern Agricultural Research Center, consulted with colleagues in Canada and North Dakota, researched a variety of cropping systems, researched schedules for insecticide applications and then introduced a parasitic wasp to prey on the midge with great hopes.
The midge just kept going, however. By 2009, evidence was mounting that the midge was starting to spread across the state. Extension agents, including Fine, were seeing adult species in their traps, some of them steadily increasing.
“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.”
A live-tracking website was set up called Montana Pestweb, to show the spread of the midge. Six Montana Agricultural Research Centers and 26 MSU Extension offices worked with growers and crop consultants to place the hundreds of traps across the state. Local producers were trained by extension agents in the biology of the pest: How to track it, what insecticides would be effective and most importantly when and when not to spray.
There is only one known gene in the world that provides resistance to orange blossom midge. North Dakota State University colleagues provided the gene to Montana researchers. It is called SM1, and it produces toxins that will kill the midge when it burrows into the developing wheat seed.
The work wasn’t over, of course, now that Montana had some of the SM1 gene to work with. It was just beginning.
Talbert used the gene to cross into Montana adapted varieties using traditional breeding techniques to find a suitable variety with resistance.
Six years later, they had a variety with reasonably high grain protein and strong yield potential under high-yield conditions, which is also resistant to stripe-rust, a wheat disease in Montana that can also limit yields.
It is a little taller than typical varieties grown under irrigation in the Flathead Valley, so stems may bend over — known as lodging — under very high yield levels.
Because of Egan’s potency, researchers are recommending it be blended with 10 percent of a non-resistant variety to delay the midge from developing resistance. That way, a small population of normal midges continues to survive and breed with any potentially resistant midges, keeping them all susceptible to Egan. Under this system, midges will continue to exist, but not in numbers that devastate a crop.
“We’re using nature’s greatest tools against itself, so it’s a natural form of resistance,” Talbert said.
Egan has been tested at seven research centers across Montana including EARC, and last spring the seed was given 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 in the history of the university. Growers must sign an agreement to use only the certified seed blend.
Bill Grey is recently retired from the Montana Foundation Seed Program.
“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,” Bill Grey 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.”