ADDENDUM TO SIMPLIFIED HOME ORCHARD SPRAY SCHEDULE
If you read some of the university home orchard spray schedules we have linked to, you will note that they recommend you spray a bit more often than our simplified schedule -- specifically, they recommend you get at least two fungicide sprays on before bloom, and they recommend summer cover sprays every 10 to 14 days instead of the 21-day intervals that I recommend.
In many years I think my simplified spray program is reasonably adequate for home orchards. In rainy springs and summers, you should tilt toward the university schedules.
I recently learned that a wonderful commercial fungicide, Nova, has been formulated in a home product, Spectracide's IMMUNOX.
To get the absolute most out of Nova (Spectracide's Immunox), modify our Simplified Spray schedule as follows: Change spray #2 into sprays 2A and 2B. Spray #2A goes on at blossom stage ¼-inch green to ½-inch green. Spray #2B goes on ten days later or at pink, whichever occurs later. Sprays 2B, 3, and 4 will have Nova added to what you intended to otherwise spray at these times. (Don't waste your Nova in sprays after #4). With the addition of Nova to the home spray schedule as suggested here, the home grower can basically kiss three spring apple diseases -- Scab, Cedar Apple Rust, and Powdery Mildew -- goodbye for the season. It's almost like magic.