Preventive Fungicide Program
A rotating schedule of protectant contact fungicides for foliar diseases on vegetables, fruit and ornamentals.
Reach for a preventive fungicide program before symptoms appear, not after — contact fungicides protect uninfected tissue but do nothing to cure lesions that already exist. This is the standard first line of defense for blight- and leaf-spot-prone crops in humid or rainy regions.
Step-by-step protocol
- Start at first true-leaf stage or 14 days before typical outbreak.
- Apply chlorothalonil (720 g/L) at 2 mL/L every 7–10 days as a protectant.
- Rotate with mancozeb (80% WP) at 2 g/L to prevent resistance.
- Add copper hydroxide during flowering for combined bacterial cover.
- Observe the pre-harvest interval printed on each label; wear full PPE.
Frequently asked questions
When should I start a preventive fungicide program?
Begin at the first true-leaf stage, or roughly 14 days before the typical outbreak date for your region, since contact fungicides only protect tissue they're already applied to.
Why rotate between chlorothalonil and mancozeb?
Rotating active ingredients with different modes of action slows the pathogen's ability to develop resistance, keeping both products effective for longer.
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