High levels of the disease last year mean farmers have to watch what they seed and pay close attention to the weather
Fusarium pressure was high in last year’s prairie wheat crop, and that doesn’t bode well for this year.
“With all this disease from last year, the land is now reinoculated for 2017,” said Holly Gelech of BioVision Seed Labs.
“Those nodes hold a massive amount of spores … and they are going to impact the 2017 crop.”
Of the spring wheat samples tested by BioVision since the harvest of 2016, “in Manitoba, 92 percent of the samples detected this pathogen in it. It tends to run between 70 to 90 percent of the samples detect the pathogen,” Gelech said during a presentation at the recent Bayer SeedGrowth Expo in Saskatoon.
Fusarium graminearum was present in 87 percent of the spring wheat samples that BioVision tested from Saskatchewan.
“In 2016 in Alberta, 35 percent of the samples that we tested detected fusarium graminearum. It’s a huge amount. Alberta tends to be about 20 percent,” Gelech said.
BioVision uses plate tests, in which 200 random seeds are taken from samples, placed on a potato dextrose agar, plated and then put in an incubation chamber for five days. The spores and fungus that originate from each seed are then analyzed.
The lowest possible disease detection of the sample is .5 percent, which occurs when one out of the 200 seeds tested has fusarium graminearum grow out of it.
“In Manitoba, the average level of fusarium infection in the fusarium testing that we’ve done this year is 12 percent, and in Saskatchewan it’s 10.8 percent,” she said.
“In the year prior, Manitoba and Saskatchewan had much lower levels of infection. Low-level infections are typical in Alberta. The average infection that we are seeing in Alberta this year is two percent.”
Even more startling is the percentage of winter wheat samples that BioVision tested from last year in which fusarium graminearum is present.
“This is a critical disease in the winter wheat. In Alberta, 16 percent of the samples we test have the pathogen, fusarium graminearum,” she said. “In Manitoba, 100 percent of the samples we tested have the disease, and the same thing for Saskatchewan.”
One hundred percent of the winter wheat samples tested from Saskatchewan had fusarium graminearum present from 2012-14.
It was the same in Manitoba in 2014, while only 25 percent of samples tested positive the following year. The sample size is considerably smaller than the spring wheat sample set because of the limited acres of winter wheat grown in Western Canada.
Fusarium can be detrimental to producers’ bottom lines.
“Grain grade deduction has been significant for all wheat classes in all three provinces. When you have .25 by weight FDK, you have it downgraded. You’ve now downgraded to a two, and then .8 to a three, and all the way down the line.”
She said it’s crucial that growers source quality seed with low levels of disease.
The custom treating trials BioVision Seed Labs conducted this year showed a significant increase of seed germination after they had a seed treatment applied.
“We ran a trial of 100 samples of wheat from across Western Canada, so all different geographies with all different disease levels,” Gelech said.
“The average of those 100 samples was 89.6 percent (germination). When we reran the test with custom treating in the lab, we were able to increase that germination by five percent to 94.5 percent.”
She said wheat growers have to pay close attention to the weather conditions when their crops are coming into flowering.
Both the Alberta and Saskatchewan agriculture departments have useful predictive models for disease development on their websites, she added.
“Look at the disease triangle. You have the inoculum because we know last year was a heavy disease year, and you have a host crop, which are your cereal grains,” she said.
“So now do you have the weather? It’s dynamite if it’s high relative humidity and very moist in the crop. Heavy dews, some rain: that’s incredibly conducive to the development of the disease.”
Increasing the seeding rate is another management practice that growers can use to resist losses caused by fusarium.
“What it does is it pushes the crop so it all matures at the same time so that you don’t have a pile of tillers that are flowering longer than the rest of the crop, which can cause higher disease.”