How the schedule is built
Each spray protects the canopy for a limited time: the product’s persistence, or the minimum interval between applications on its label. The planner adds that interval to the last spray again and again to give the next dates.
The list stops at the last day you can still spray before harvest: the expected harvest date minus the pre-harvest interval (PHI) of the product you plan to use late in the season. If the product limits the number of applications per season, the list also stops when those run out.
Example
Last spray on 1 June, 10-day interval, harvest expected on 15 September with a 28-day PHI. The last usable day is 18 August, so the planner lists 7 sprays, from 11 June to 10 August. If the product allows 8 applications and 3 are already done, it stops after 5: from 11 June to 21 July.
Frequently asked questions
What interval should I use?
The one on the label, or a shorter one when disease pressure is high, shoots grow fast or rain washes the product off. Contact products usually need 7–10 days; systemic products often allow 10–14.
Why does the schedule end before harvest?
Because the last spray must respect the pre-harvest interval. Spraying after harvest − PHI would leave residues above the legal limit at picking.
Should I always spray on these dates?
No. They are when protection runs out, not an order to spray. Dry weather and low disease risk can justify waiting; an infection warning can justify spraying sooner.