Withholding period calculator
Work out the earliest date a block can be harvested after spraying. Add every spray that has gone on since the last harvest — where they overlap, the longest interval is the one that counts.
Enter a date applied and the withholding period from the label to see the earliest harvest date.
This calculator does not know any product's withholding period, and never guesses one. It varies by product, by crop and by dose, and labels are revised. Read the period off the label you actually used — this does the date arithmetic from there. Harvesting inside the window risks residues above the Maximum Residue Limit, which is how a load gets rejected at a packhouse or a border.
Questions growers ask
What is a withholding period?
The number of days that must pass between spraying a crop and harvesting it, so residues fall below the Maximum Residue Limit. It is set per product and per crop, and printed on the label of the registered remedy.
Where do I find the withholding period for my product?
On the product label. Agricultural remedies sold in South Africa are registered under the Fertilizers, Farm Feeds, Agricultural Remedies and Stock Remedies Act 36 of 1947, and the registered label carries both the L-number and the withholding period for each crop the product is registered on.
I sprayed twice. Which period applies?
The one that finishes last. A short-interval product sprayed yesterday does not release a block that a long-interval product is still holding, so the latest clear date across every spray is the one that governs.
Does the day of spraying count as day one?
This calculator counts the days after application, so a 14-day period on a spray applied on the 1st clears on the 15th. If your label or your buyer counts differently, follow the label.
What happens if I harvest early?
Residues may exceed the Maximum Residue Limit for that crop. In practice that means a consignment can be rejected at the packhouse or at a border, and it is the kind of thing a GLOBALG.A.P. audit looks for in your spray records.
Is the re-entry interval the same thing?
No. The re-entry interval is how long before people may work in the block again, measured in hours from application. The withholding period is about the produce. Both are on the label and they are usually very different numbers.
Rather not do this by hand every time?
isibaya keeps the spray record and warns you before a planned harvest lands inside a withholding period — while you are still typing it, not after the sprayer is empty.