Fusarium has dragged down the profitability of Manitoba’s hog industry and is snapping at the throat of the province’s hopes to establish an ethanol industry.
It has repeatedly ravaged some farmers’ cereal crops in eastern Saskatchewan and is moving west each year. Alberta now requires eastern prairie seed be tested for fusarium and treated with a fungicide. And researchers doubt they will be able to find a single strong cure. The good news is that they might be able to hit it with several weapons that will stagger, if not eliminate, the crop disease.
Read Also
Canada-U.S. trade relationship called complex
Trade issues existed long before U.S. president Donald Trump and his on-again, off-again tariffs came along, said panelists at a policy summit last month.
“I think we’re going to (continue to make) incremental advances and all of a sudden we’re going to get a whole bunch of varieties out that are considered resistant,” said Andy Tekauz, a barley and oat researcher with the Agriculture Canada research centre in Winnipeg. “Until then it’s going to be one or two (varieties).”
Some wheats and barleys have small amounts of natural resistance to fusarium, but good resistance is found in only a couple of new wheat varieties, such as HY 644 and Alsen, which have been stuck in the research and development pipeline.
A surge of new resistant varieties probably won’t hit the market for another five to 10 years.
Tekauz and colleague Jeannie Gilbert have been looking for answers to the fusarium plague that has afflicted the eastern Prairies since the early 1990s.
Fusarium has always been present on the Prairies, but never erupted the way it did in 1993 in the Red River Valley, when it ravaged cereal crops and shocked producers with its virulence.
In the years since 1993, fusarium infections have spread and become worse in other parts of Manitoba and eastern Saskatchewan. Many farmers in the Red River Valley have simply given up growing wheat and barley, causing big problems for the hog industry that relies on local feed.
This summer the fusarium problem wasn’t bad, but researchers warn that this was only because the Prairies were dry during wheat flowering. The disease hasn’t gone away and will strike whenever conditions are right. The soil is rich with fusarium spores after years of infections.
Gilbert, a plant pathologist specializing in wheat, said farmers shouldn’t expect fusarium to be eliminated by the creation of super-resistant varieties of wheat and barley. Total eradication is impossible.
“There is no immunity,” said Gilbert.
“And we probably wouldn’t want that. It would put tremendous selection pressure on the disease (to adapt and overcome the resistance).”
But Gilbert is confident that varieties can be developed that will minimize fusarium infections and stop the disease from being a crop wrecker.
Researchers are working on fast methods of developing resistant varieties of wheat.
“We’re finding where on the genome the resistance is and looking for the resistance in the seed rather than growing it up in the field and looking for the reaction,” said Gilbert.
“That’s why the molecular (research) side is going to be so exciting.”
Resistance to fusarium does not appear to be caused by a single gene, but by a combination of genes acting together to weaken the disease.
Researchers had hoped to have several fusarium resistant varieties already in farmers’ hands, but it has been hard to transfer the resistance from some promising, fusarium-resistant plant germplasm from China into hardy, quality strains of Canadian prairie wheat.
“We didn’t realize what a drag that resistance would result in, in quality and agronomics,” said Tekauz.
“They brought their resistance, but also a lot of detrimental factors.”
Researchers are also looking at semi-wild cereal grain varieties that have strong fusarium resistance. Tekauz said this is important because if a number of fusarium resistant varieties are developed, all relying on one source of resistance, the disease could eventually adapt to overcome it. By developing an additional source, the risk could be lowered.
Wheat farmers are able to use a spray-on fungicide to control fusarium infection during flowering in wheat, but there are no similar products for barley and oats. Tekauz said research in those crops is a few years behind wheat.
For now, and even once resistant cereal varieties are developed, farmers will have to rely upon a multi-faceted approach to control the disease.
“It has to be an integrated approach because we don’t have a silver bullet,” said Tekauz.
To control the disease, farmers need to be careful with their rotations to minimize the yearly buildup of fusarium spores in straw. They should also choose semi-resistant varieties of cereals, which are ranked and listed in seed guides and in provincial agriculture department publications.
They will need to watch temperature and humidity when cereals are flowering to know if and when to spray a fungicide.
When resistant varieties finally roll out of the labs into farmers’ hands, they will provide an effective weapon. But that should not be an excuse to discontinue the other control methods, Tekauz said.
He and Gilbert work across the street from the Dominion Rust Laboratory, the facility in which researchers broke the back of the rust disease infections that ruined thousands of farmers’ crops in the early 20th century.
They know their fight today is similar.
“Fusarium has taken over from rust,” said Tekauz.
But with diligent work and modern scientific methods, Tekauz and Gilbert think fusarium can be limited to occasional eruptions.
“I’m very optimistic,” said Tekauz.
