Prevention in the vineyard is key to avoid problems with powdery mildew. Dealing with a Vineyard Powdery Mildew Outbreak. When it comes to diseases that Powdery Mildew – Symptoms and Disease Control … Powdery Midew is a type of crop disease which affects crops like Carrot, Cucumber, Okro, Tomato, Hot pepper, Sweet pepper, etc. https://www.advancednutrients.com/articles/powdery-mildew-prevention According to OSU’s Extension Service’s website, “The best powdery mildew …