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Pre-Harvest Intervals JUL 12 2023 | New Growers and Producers | Agronomy and Blog Post

By Sheri Strydhorst, PhD, PAg – Sheri’s Ag Consulting Inc.

Understanding and complying with Pre-Harvest Intervals (PHIs) are critical for safe pulse crop production. 

WHO? All pulse growers who use pesticides. It is particularly important for pulse growers who need to spray herbicides, fungicides or insecticides later in the growing season.

WHAT? The PHI is the MINIMUM amount of time between applying a pesticide and swathing or harvesting the crop.

WHEN? The PHI for many pulse fungicides is 14 to 30 days. For example, if a pulse crop is intended to be swathed or harvested on August 15th, you cannot spray certain fungicides later than July 16th or August 1st, depending on the product. The PHI for harvest aids is 2 to 10 days and the PHI for insecticides ranges from 1 to 30 days.

WHY? Compliance with PHIs is a legal requirement to ensure that pesticide residues do not exceed the maximum residue limits (MRL), established by the Food and Drugs Act (FDA). If your pulse crop is found to have residue levels which exceed the MRLs, the grain could be seized, destroyed or forbidden for export.

HOW? PHI information is found on pesticide labels, the Keep it Clean website and in The Blue Book.

Learn more in the video below as Dr. Strydhorst discusses PHIs with APG’s Dr. Jenn Walker.