This is what I found for you:
Preventatives: if you know you have a susceptible plant, you can consider regular sprays to avoid infections. Preventatives include:
Sulfur: used for centuries, sulfur is most effective when applied in wettable form (such as Safer Garden Fungicide). Note that sulfur can damage ornamental plants; do not apply above 90°F or within two weeks of an oil spray.
Bicarbonates: available in the form of potassium bicarbonate (Kaligreen) and home-made solutions using baking soda. Be careful to avoid injury to the plants, and note that baking soda can have adverse effects on the soil when over used. Baking soda solutions can use salad oil as a spreader-sticker, or horticultural oil (which adds eradicant capabilities).
The biological fungicide Serenade contains a bacterium which helps prevent infections from occurring.
Mary Louise Flint, University of California at Davis, Director of UC Integrated Pest Management Education & Publications says, “A simple fungicide can be made at home by combining 2-1/2 tablespoons of horticultural oil (Sunspray Ultra-Fine, Saf-T-Side, etc.) in a gallon of water and adding 4 teaspoons baking soda. This solution is sprayed on plants to prevent powdery mildew infections. Sprays of both potassium bicarbonate and baking soda can injure the plant, so use these materials with caution. Also, baking soda sprays can have deleterious effects on soil structure and should be used sparingly.”
Eradicants: Once you have active symptoms, you may need an eradicant to kill the infection to avoid further damage. Since the established PM is a parasite to the host plant, using a preventative to avoiding spreading will not stop damage to the plant. Eradicants include:
Horticultural oils such as JMS Stylet Oil, Saf-T-Side Spray or Sunspray Ultra-Fine Spray Oil.
Plant based oils including neem oil or jojoba oil.
The biological fungicide AQ10 contains a parasitic fungicide that attacks the PM fungus.
Combination: Unfortunately, sprays combining both preventative and eradicant qualities fall mostly into the synthetic fungicide category and are least recommended from an IPM viewpoint. The least toxic combination seems to be Potassium Bicarbonate, which, while primarily preventative, has some eradicant capability.
Hope you can use this. Try and find them native ladybugs
