The Alberta government has given up trying to battle fusarium head blight through regulation — but the move means farmers will need to up their game to control the hugely costly cereal disease.
The province removed fusarium graminearum from the Pest Control Nuisance Regulation of the Agricultural Pests Act last month, bringing Alberta in line with other provinces. The regulation meant producers had to test seed for all vulnerable crops, and couldn’t buy or sell seed with detectable levels of fusarium.
But even while admitting “regulating fusarium has failed to stop its spread,” the government and cereal industry officials are hoping the change will prompt farmers to increase their efforts to control a disease that costs Canadian growers upwards of $300 million in a bad infection year.
“This ruling brings another level of awareness to it,” said Sarah Foster, president of 20/20 Seed Labs.
In the past, some growers may have just applied a fungicide and hoped they got the timing right, she said.
“That’s not the only answer. There’s a lot of aspects that have to be considered.”
The first step to prevent fusarium from building up in your field is to use seed with fusarium resistance. Crop rotation, seed treatment, monitoring the field, and proper fungicide timing and application are all critical tools to prevent or control fusarium.
But testing also needs to be widespread if growers want to halt the two-decades-long spread of the disease in Alberta, Foster said. Before the removal of fusarium graminearum from the pest control act, many farmers had to try to achieve zero levels of fusarium in their seed, which is almost unattainable, she said.
“We’re being realistic now. We know that there are areas that are relatively free or zero, but it’s becoming fewer and fewer,” she said.
There are two ways to test for fusarium. A DNA test using something called the PCR method is more sensitive, and can test more seed, with results available within two days.
“The beauty with it is that it’s quick, sensitive and accurate and it will find traces of fusarium,” she said.
Another test, which takes five to seven days, gives a percentage of fusarium graminearum infection in each sample of 200 seeds to 0.5 per cent.
If a producer is in an area with low or zero infection, Foster recommends both tests, which she said cost less than $150 each.
“Do a PCR and then a plate test if it’s positive,” she said. “If it’s negative, we’ve not picked anything up. It’s an early indication, if you use that DNA test that fusarium has come into the area if we pick it up. If we pick it up on the plate test, it’s already well established.”
Fusarium risk maps have been available since 2006. In some counties, like those south of the Trans-Canada Highway, Foster recommends a plate test.
“We’re going to pick up solid results from that,” she said. “It’s all the other areas where there’s an ebb and flow and fusarium is so dependent on climate. Last year, there was a definite uptick in the amount of fusarium that was found because of wet conditions.
“Any time there is a wet year, we know that there is going to be a fusarium increase.”
Foster has also been working with some producers using Spornados, which can detect fusarium spore loads in fields.
She also advocates using seed treatment to protect against fusarium. Proper crop rotation and sourcing clean seed are also recommended.
Producers should also select varieties with a higher fusarium tolerance, said Jeremy Boychyn, an agronomist with Alberta Barley and Alberta Wheat.
They can also increase their seeding rates and stagger planting dates (planting some wheat first and more later on) so that only one of the crops could be impacted. Producers using irrigation should make sure they reduce the amount of water applied during heading and anthesis to reduce the risk.
Controlling fusarium is now in the hands of producers, Boychyn said.
“Testing is going to be more important,” he said. “Depending on what part of Alberta (the producer) is in, the management plan will potentially change depending where they are. Some areas of southern Alberta have been in fusarium for a number of years, and they have a high amount of inoculum.
“It’s going to be a different management situation than for people in the north, who have only seen it every few years and the inoculum isn’t high.”
But that can change in a field if fusarium-infected seed is used — that increases the number of fusarium-infected kernels, which produce more spores, which cause more plants to become infected, more inoculum to spread, and so on.
“If your field is clear of fusarium and you introduce a fusarium-infected kernel, you will introduce fusarium-infected spores into your field that will impact future crops,” he said.
Testing is the only way to know the threat level — although wet conditions up the risk considerably.
“Last year, we saw an uptick in the amount of fusarium being seen in some of the seed-testing labs,” he said. “We’re in a risk year (this year) if we continue to see high moisture.
“This comes down to looking at the fusarium risk map, and seeing if your area is of high risk, and if it is, spraying with a head blight timing application fungicide.”
Boychyn recommends producers look at www.managefhb.ca, a new website that offers best management practices and other information on fusarium. Producers should also find out the fusarium situation in their area by speaking to local agronomists and fieldmen from their municipal district.