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Tip #2:
Always Read and Follow the Label

Before you apply any crop protection product, read and follow the label for application rate, timing and pre-harvest interval (PHI). Improper or off-label use of pesticides is illegal and may result in unacceptable residues, putting market access at risk. Before you spray always read and follow the crop protection label for application:


Always follow the correct application rate. MRLs are established based on the product label’s application rate. Following the label’s application rate and maximum number of applications per year reduces the risk of unacceptable residues in the harvested grain.


Apply crop protection products only at the recommended crop stage. For example, glyphosate for pre-harvest weed control should only be applied once grain moisture is less than 30% in the least mature areas of the field. Applications made too early increase the risk of unacceptable residue in the grain. Refer to the Pre-Harvest Glyphosate Staging Guide for visual examples of various crops at 30% grain moisture.


Follow the product’s pre-harvest interval (PHI) – the number of days between spraying and swathing or straight-cutting the crop. PHIs are set to ensure a product’s active ingredient has enough time to break down in the plant and not leave unacceptable residues behind.

PHIs can vary greatly between products – from as little as none (zero PHI) to up to 60 days. As harvest approaches pesticide choices become more limited, based on the PHI, but it is crucial to stick to the product’s PHI even if your crop is facing a late- season threat.

Growers are encouraged to review our Product Advisory to be aware of market risks that can arise from using certain crop protection products on some crop types, before proceeding with crop management plans.

To help time applications or choose an acceptable product, canola and pulse growers can use the Keep it Clean Pre-Harvest Interval Calculator, an interactive interval tracking tool.

If you require clarification about information found on the label, or have further questions, contact the manufacturer before proceeding.

Additional Resources

Pre-Harvest Glyphosate Staging Guide

An illustrated guide to help manage pre-harvest application of glyphosate and determine when grain moisture content is less than 30% in the least mature part of the field.

Pre-Harvest Interval Calculator

An interactive tool to find a pesticide to suit your application timeline or to calculate pre-harvest interval (PHI) – the number of days to wait after product application before swathing or straight-cutting the crop.

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