Pre-harvest interval

It is not in a calendar but in the authorisation of the individual product — and it differs from product to product, roughly between a few days and several weeks in winegrowing.

The point of it: by the time you pick, residues should have fallen below the permitted maximum. Break the interval and you have a problem you cannot see on the grape and that only shows up in the laboratory.

So the interval is not a question of record keeping but of planning: it has to be known before the application, not after the harvest. It is usually abbreviated PHI.