How can I effectively treat powdery mildew on my pumpkin leaves?

To effectively treat powdery mildew on pumpkin leaves, you can use a mixture of water and baking soda as a natural fungicide. Simply mix 1 tablespoon of baking soda with 1 gallon of water and spray it on the affected leaves. Repeat this treatment every 7-14 days until the mildew is under control. Additionally, make sure to prune any affected leaves and provide good air circulation around the plants to prevent further spread of the disease.