Thanks a lot, will try Neem oil.
Another recipe from internet, will try this one too.
----------------------------
Baking Soda (sodium bicarbonate) -This is possibly the best known of the
home-made, organic solutions for powdery mildew. Although studies indicate
that baking soda alone is not all that effective, when combined with
horticultural grade or dormant oil and liquid soap, efficacy is very good if
applied in the early stages or before an outbreak occurs.
Use this recipe to make your own solution—mix one tablespoon of baking soda
with a teaspoon of dormant oil and one teaspoon of insecticidal or liquid
soap (not detergent) to a gallon of water. Spray on plants every one to two
weeks.
----------------------------
