Tools and Resources for Determining the Right Pre-Harvest Interval

When problems pop up during the growing season, such as weeds, pests or crop disease, you’ll want to nip them in the bud early on to ensure your harvest isn’t affected in the fall. Whether you’re applying an insecticide, fungicide, desiccant or herbicide, application timing is a crucial consideration for complying with the product’s pre-harvest interval, or PHI (the time between chemical application and when the crop is swathed, desiccated or straight-cut).

Export markets have strict regulations on the amount of trace residues they allow on various crops and will reject any imports that do not meet these parameters. To help protect the integrity and reputation of Canadian agriculture in the global market, ensure that you meet the guidelines set out for your specific crops and follow the instructions on product labels. Below are some additional resources to help you determine your PHI, which differs depending on crop type, so that you can better manage the trace residues on your harvest.

Spray to Swath

Spray to Swath Interval Calculator

Keep it Clean! has a handy PHI calculator to help  producers determine how many days are required between pesticide application and cutting. You can find calculations for products you’ve already applied, use a calendar to specify what and when you plan to spray and when you can harvest, or find product options based on your needs and timelines. There are numerous products to choose from when scrolling through the lists on this site, making it easy to find what you’ve already used or discover a new solution that will work for you and your crop.

Keep It Clean

Keep it Clean! – Cereals

If you’re a cereal producer, these cereal export guidelines outline five simple steps for getting your harvest ready for market. These tips include details about product use for specific cereals, how to handle common cereal issues and ways to successfully store and deliver your crop.

Keep it Clean! – Pulses

Pulse producers will appreciate these market access guidelines, which offer a brief look at the pulse industry and export markets and provide four easy steps to get pulse crops ready to export around the world. The tips touch on product application and timing and provide pulse growers with a useful, detailed resource on how crop protection products can impact market access.

Keep it Clean! – Canola

This market access guide for canola provides extensive information about canola-specific protection products and offers growers five pointers for ensuring market access worldwide. Specific crop protection product types are outlined, and information about crop selection, storage, and delivery are also included here. The page also has a link to important information on the Canola Council of Canada’s website, which discusses market access for canola producers in further detail.

Using Pre-Harvest Herbicides in Soybeans

Ontario’s Ministry of Agriculture, Food and Rural Affairs produces a newsletter called “Crop Talk”, and this article on PHIs in soybeans discusses the ins and outs of applying pre-harvest herbicides on soybean fields. Weed types and product options are touched on, and the article also goes into detail about application timing based on various treatments and weed types, complete with a great quick-reference chart for producers.

Outline of Opportunities in China

In this outline of trade opportunities in China, Agriculture and Agri-Food Canada provides information about export opportunities with Canada’s third-largest trading partner. While not specific to growers, the information provided is a great overview of what the Chinese market looks like and how Canada’s exporters — including producers — can continue to tap into it. Useful statistics and comparisons help to explain Canada’s trade relationship with China, and there are links to the country’s most desired product types, with additional information and insight on the market for each.

Whether you’re looking to maximize your crop export potential or are just seeking helpful tips to ensure PHI compliance, these resources are a great starting point.