Cedar-Apple Rust on Apples: Fungicide Rotation Needed

Apples have yellow leaf spots (cedar-apple rust) despite spraying "Complete Fruit Tree Spray" (Bonide: captan, malathion, carbaryl). Owner asks what fungicide to add.

Problem: Inadequate Fungicide Coverage

Bonide's captan targets fruit rots, not cedar-apple rust. The disease may also overwhelm the fungicide with massive spore loads.

Solution: Add Maneb and Rotate

1. Start at 50% bloom next spring.
2. Spray every 10–14 days, alternating Bonide with Maneb.
3. Continue until fruit near full size.
4. Observe PHI: Maneb may require 30-day pre-harvest interval.

Why Rotation Works

Maneb protects leaves better against the rust fungus. Rotation prevents resistance and covers both insects (Bonide) and disease (Maneb).