AN INVESTIGATIVE STUDY LOOKS AT HOW FUNGICIDE APPLICATIONS MAY IMPACT YIELD RATINGS IN THE ONTARIO CEREAL PERFORMANCE TRIALS
production practices in Ontario agriculture are constantly changing. As new inputs and new varieties become available, it becomes increasingly important that farmers have access to the best, most accurate and impartial data available.
With this in mind, the Ontario Cereal Crop Committee (OCCC) – responsible for publishing the Ontario Cereal Performance Trials – are embarking on an investigative study to determine if they should begin providing data for “managed cereal trials” in their reports.
“More and more farmers are using fungicides and historically, the performance trials are not sprayed,” explains Peter Johnson of the discrepancy between field practices and the trials. Johnson is the Ontario Ministry of Agriculture, Food and Rural Affairs’ wheat specialist and an OCCC representative.
“In an effort to ensure we are providing farmers with the most accurate information, the committee is exploring whether or not fungicides will change the yield rankings in the performance trials,” Johnson continues.
As part of this exploratory study, plots of “managed” cereal varieties are planted alongside “unmanaged” plots of the same variety. The “managed” plots are treated with fungicides at weed control timing and Fusarium control timing while the “unmanaged” plots receive no treatment. Each trial has four repetitions of the sprayed plots and four repetitions of the unsprayed plots for an eight repetition trial.
“We’re intrigued by the potential of altered yield rankings,” says Johnson. “We want to be able to compare the different results of varieties that have low-tolerance and high-tolerance to Fusarium and other diseases. If Variety A is susceptible to a disease it may be very low yielding compared to a high-tolerance variety when unmanaged. But, those rankings may change once fungicides are utilized,” continues Johnson.
driven by resistance loss
“One of the drivers of this research was the fact that we lost our crown rust resistance in oats,” says Johnson.
In 2007 oat varieties that were once genetically resistant to crown rust began to show symptoms of the disease. This change is not uncommon as disease organisms adapt and change over time and eventually it can change to the point where it is no longer stopped by the genetic resistance built into the plant.
“The oat variety Sherwood used to be the highest yielding with full resistance,” says Johnson. “But now that the resistance has been broken, Sherwood appears to be more impacted by crown rust; it went from a 120 yield index to 88. We want to see if that 120 yield index potential still exists through the use of fungicides.”
gathering the data
This change in resistance pushed the committee to explore the possibility of managed trials in March 2009. To date, the committee has two years of results from spring cereals and one year of results from winter cereals.
The trials distributed with this issue of the magazine do not incorporate the results of this year’s managed trials. Johnson explains that “as trials in previous years were not sprayed, the committee did not feel managed trial results should be incorporated.” However, growers can view the results of the OCCC website at www.gocereals.ca. When viewing these results, Johnson cautions farmers to remember “that these results are only from a single year. You cannot make good decisions based on only one year of data.”
The managed trials are part of a three-year preliminary study. “If, after the three years, we find that there is no difference between unmanaged and managed trials, then we’ll abandon this activity,” explains Johnson. “But, if there is a significant difference between the two, we will certainly continue with the trials and report our finding to Ontario farmers.”
This research is funded in part through Growing Forward, a federal-provincial-territorial initiative. The Agricultural Adaptation Council assists in the delivery of several Growing Forward programs in Ontario. Syngenta and Bayer CropScience have also provided funding for this research and site coordinators donate their time and energy to make these trials possible. •