Chemical Remedies
Sulphur
Examples:
Safer Garden Fungicide, Orthoganics Garden Sulphur.
Effective Against:
Powdery mildew, black spot, rust, scab, damping-off fungi.
Crops:
Flowers, foliage plants, ornamentals, and some food crops (peas, beans, grapes, strawberries).
Counteracts these pest(s):
Black Spot (See Problem Plants - Page D12)
When To Use:
Apply to affected plants at the first sign of symptoms, to prevent spread of disease to unaffected areas and new growth. Mildew is reduced by growing plants in sunny locations with good air circulation and by reducing water contact on leaf surfaces.
How To Use:
Some products are pre-mixed and ready to use. Wettable sulphur must be mixed as directed before application. Always read label directions completely before using. Apply to leaf surface, top and bottom.
Benefits:
Less toxic than most fungicides. Natural origin.
Concerns:
Can cause eye irritation. Works as a preventative only, so repeat applications are necessary every 7 to 14 days especially in rainy times. Curcubits and roses may be damaged by sulphur, so test on a small area first. Can cause fruit drop once fruit has appeared.