Pre-harvest interval (PHI) refers to the amount of time that must lapse (in days) after a pesticide application before the crop is cut. Cutting refers to swathing or straight combining. Each crop protection product has its own PHI, and the PHI for a specific product often vary by crop.
The Canola Council of Canada has an easy-to-use tool called the “Spray to Swath Interval Calculator” (shown above) to identify product options for insect and disease management in canola based on the estimated time between spraying a crop and cutting it.
Failing to comply with a product’s pre-harvest interval is a contravention of the Pest Control Products Act (PCP). The PCP Act was put in place to protect human health and safety and the environment by regulating products used for the control of pests. It is important to adhere to the PHI to ensure no unacceptable chemical residues will be found in harvested seed. Adhering to the PHI ensures canola is safe for domestic consumption/use or export. With 90% of Canada’s canola crop exported around the world, it is critical that our canola meets the requirements of our export customers.
Podcast: Keith Gabert discusses when pesticide applications can be made in relation to swathing and harvest Click to Listen