More to explore:
Antifungal Rose Spray-http://www.food.com/recipe/antifungal-rose-spray-49604
Homemade Anti-Fungal Spray for Black Spot on Roses:Ingredients: Vegetable Oil Water Liquid Dish soap One 25-32 oz. spray bottle (reuse a windex type bottle, Recipe: Combine 1/2 a teaspoon of dish soap with 1/2 a teaspoon of vegetable oil in your spray bottle, and fill completely with water, leaving only enough room for the straw and cap to screw on without overflow. Lightly shake, and then liberally spray this anti-fungal spray all over your roses, leaves, blooms and all.