The pre-harvest interval is the?

• A. Time to re-enter the field after spraying.
• B. Amount of time that a crop can be harvested after it has been sprayed.
• C. The window for applying pesticides after harvest.
• D. The date by which products must be re-labeled.

Answer: (B)

The pre-harvest interval is the minimum time that must pass between the last pesticide application and harvest to ensure residues stay within legal limits. This is why the best description is the time a crop can be harvested after it has been sprayed—the label sets this interval in days and it’s specific to both the product and the crop. Always follow the label for the exact PHI, because it can vary by product, crop, and application rate.

For context, other concepts have different meanings: re-entry interval is about how soon workers can enter a sprayed field after application, not when you can harvest; applying pesticides after harvest isn’t an allowed use in most cases and isn’t PHI; and labeling requirements for re-labeling are separate from PHI. If, for example, the PHI is 14 days, you’d wait at least 14 days after the last spray before harvesting.