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Tuesday, August 21, 2018

Tips to achieve the most effective fungicide application

fungicide application

If you grow wheat or barley and want higher yields, greater bushel weights, better grain quality and lower disease losses, using fungicide properly needs to be part of your growing season plan. Research shows fungicide supports all these goals, is cost-effective, and improves your returns per acre.

When and how should you use fungicide to reach those goals?

When left untreated, your crop is susceptible to diseases

When left untreated, your crop is susceptible to diseases

Know how fungicide works

Fungicide is a preventative tool – meaning you need to apply it before any signs of trouble for it to deliver full impact. Herbicides work in the opposite way—when you see a problem, you apply herbicide to fix the problem.

Know your disease risks

If you can’t apply fungicide after you see signs of a problem, you have to figure out what diseases your crops will be susceptible to, so you can apply the right preventative fungicide ahead of time.

The most troubling diseases for Canadian wheat and barley growers are:

  • Rust diseases like stripe rust
  • Leaf spot diseases such as tan spot and spot blotch
  • Head diseases, particularly fusarium head blight (FHB)

Grow Your Knowledge: Diseases in Cereals

Understand how diseases are transmitted

Many fungal diseases are seed-borne—so using seed treated with fungicide is your best first step at disease prevention. You may also need to apply fungicide separately, to prevent infection from spores in crop residue or soil, or from spores that blow in from nearby fields.

To determine whether to apply fungicide after planting, consider how susceptible the variety you planted is, and pay close attention to weather conditions that can make plants more or less likely to fall victim.

Identifying the optimal time to spray fungicide can increase your yield.

Identifying the optimal time to spray fungicide can increase your yield.

Plan fungicide timing around the specific threat

Many growers may be in the habit of applying half rate fungicide at the same time they apply herbicide, but Agriculture and Agri-Food Canada research scientist Kelly Turkington says there is little evidence to support this practice.

Agri-Food Canada research scientist Kelly Turkington
  • Watch for stripe rust early However, Turkington says growers should scout for stripe rust at herbicide timing, because it can appear early. If you find any evidence, apply a full rate of fungicide, along with normal herbicide application.
  • Flag leaf timing protects grain fill It can be worthwhile to apply fungicide at the flag leaf stage – protecting the flag and penultimate leaves, which are responsible for grain fill. The downside is this doesn’t protect against head diseases.
  • Narrow application windows for head diseases Protecting against FHB or other head diseases can be tricky, because of small application windows. However, hitting the narrow window for head diseases also protects against leaf diseases.

Wheat Tip: Spray wheat when 15% of the crop is flowering, shortly after heading is completed.

Barley Tip: Barley timing is very fast, as little as a day in some cases. Flowering begins before the head is fully out of the sheath, so watch plants carefully and be prepared to spray quickly.

Trial results can guide application

Bayer has conducted more than 100 field trials in the prairies over the past eight years with the goal of confirming optimal fungicide application timing for cereals. Check results in your area at

Learn more about fungicide timing recommendations.

Tweak equipment setup to maximize effectiveness

Ensure your sprayer is set-up for fungicide application; fungicides typically need good plant coverage to ensure best results. Make contact with heads, stems, and leaves for the greatest impact. Tom Wolf, a spray technology specialist, says proper water volume is the most important factor to ensure good coverage.

Depending on the disease and the coverage needed, making seemingly small adjustments in your spraying equipment can ensure effectiveness. If you’re interested in making the biggest impact with your fungicide, check out Wolf’s equipment recommendations. His website,, shares tips on variables like nozzle type and spacing, droplet size, flow rate, spray angle, and much more.

Protecting the Value of Your Wheat

Tom Wolf, a spray technology specialist