The buds should be OK. If you get powdery mildew on any future plants you can use the folowwing:
Baking Soda. Baking soda itself isn’t normally effective as a powdery mildew treatment, but when it’s combined with liquid soap and water, it can be a powerful weapon. It’s normally most beneficial if used as a preventative measure rather than a treatment. Combine one tablespoon baking soda and one-half teaspoon of liquid, non-detergent soap with one gallon of water, and spray the mixture liberally on the plants.
Mouthwash. The mouthwash you may use on a daily basis for killing the germs in your mouth can also be effective at killing powdery mildew spores. Since its function is to kill germs, the powdery mildew spores can’t withstand it. Using three parts water to one part mouthwash has been found to be a good ratio, but new growth can be damaged since mouthwash is potent, so use with caution.
Milk. Milk is making its way onto the scene as a viable means to control powdery mildew. Not all the science is known, but the compounds in milk may be able to act as an antiseptic and fungicide as well as potentially increase the plant’s overall immunity. It tends to be effective as a method of preventing powdery mildew on zucchini and other types of squash, as well as cucumbers. An effective mixture ratio is about one part milk to two or three parts water.
Powdery mildew is a fungus that many plants can contract. Safer® Brand offers a variety of options for powdery mildew treatments to protect your plants.
www.saferbrand.com
To me it looks like you are harvesting early.