Crop Protection | P&H Agriculture

Crop Protection


Our crop input centres carry all major brands of crop protection products to manage weeds, insects, and diseases. We partner with the best suppliers to offer an extensive selection of crop protection products including fungicides, herbicides, insecticides, seed treatments and plant growth regulators.

P&H stands behind our products and backs them up with the agronomic expertise to make sure you always have the right product for your application. All our retail locations carry a wide range of crop protection products to fit the agronomic needs of every acre.

Our team of Certified Crop Advisors maintains a strong connection to the industry’s most knowledgeable pest, disease and weed control experts. This ensures we are always up to date on the latest crop protection technology and ready to help you grow the best possible crop for the highest ROI.

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Herbicide Resistance Management

Canada has weed resistance issues in at least six difference herbicide groups. If we ignore the risk of developing resistances … the consequences are not cheap or pretty.”

Harry Brook, crop specialist with Alberta Agriculture and Forestry

How Does Resistance Affect Me?

With more than 51 resistant biotypes, herbicide resistance is on the rise in Canada. Here on the Prairies, wild oats resistant to Group 1 and Group 2 herbicides are by far the most economically damaging biotypes. Approximately 7.7 million acres are affected by weed resistance in Alberta alone. In Manitoba, 78% of fields surveyed had Group 1 resistant wild oats. Just 16 wild oats per square metre at the 1 leaf stage of a wheat crop can reduce yields by 15%.

Resistance also affects your pre-seed and post-harvest burn-off, as five glyphosate (Group 9) resistant weeds have been confirmed in Canada. For example, Group 9 resistant kochia has been identified in all three prairie provinces. According to Manitoba Agriculture research, just 21 kochia plants per square metre can reduce wheat yields by more than 33%.

How Do I Know If I Have Resistant Weeds?

Nothing beats your shadow in the field. Scouting is vital in managing resistance, even if it’s from the cab of your combine. At harvest, you have a bird’s eye view of mature weeds that have escaped in-crop herbicide control.

Warning signs of resistance include: (provided by Harry Brook)

  1. Other weeds listed on the herbicide label being controlled adequately.
  2. Patchy control with no reasonable explanation.
  3. A history of herbicide failure in the same area.
  4. Lack of signs of herbicide injury on plants.
  5. A history of using the same herbicide group on the land, year after year.

However, resistance is not the only factor that affects herbicide performance and you must also investigate other factors of poor weed control. These factors include misapplication, spray misses, unfavourable weather conditions, and misapplication of herbicide at wrong leaf stage or late weed flushes.

How Do I Manage Resistance?

Dr. Linda Hall, an associate professor in the Faculty of Agriculture Life and Environmental Science at the University of Alberta, is an expert on this topic. “My work is anticipating and trying to solve the problems of herbicide resistant crops and weeds,” says Hall. “There are many factors influencing resistance, however, it’s the selection pressure applied over and over by the same herbicide group that results in eventual resistance.” In other words, herbicide group rotation is crucial in managing resistance.

The introduction of newer herbicide chemistry has recently provided some fresh tools in the form of new tank mixes for control of resistant weeds. Pre-emergent soil applied herbicides are also making a strong comeback. It takes more than 10 years to bring a new herbicide to market, so we must be vigilant in taking care of the tools currently available.

A brief list of Best Management Practices you can use to combat resistance include:

  1. Change it up. Use herbicides that offer multiple modes of action and follow suitable crop rotation guidelines that allow rotation of herbicide groups.
  2. Follow labels. Do not use unregistered rates of either water, herbicide or surfactant. Off label fertilizer, insecticide and fungicide mixes with herbicide can also affect efficacy.
  3. SCOUT! Before and after herbicide application.
  4. Record. Keep detailed herbicide application record AND weeds present in the field.
  5. Collect and confirm. Send weed seed samples to The Crop Protection Lab. Offered through Saskatchewan Agriculture, the Lab offers weed seed testing to provide concrete evidence of resistance, for a fee. Complete guidelines for submitting samples can be found at
  6. Plan. While options can be overwhelming, consider approaching the agronomist at your local Parrish & Heimbecker, Limited. We have the expertise and products available to help you develop a long-term resistance management plan.

For a full list of herbicide resistant weeds in Canada check out the following link provided by the Weed Science Society

Contact your local P&H to discuss crop protection products that fit your farm.