Anti-Fungal Baking Soda Spray
Common vegetable garden fungal diseases:
Powdery mildew (see photo)
Sodium bicarbonate commonly known as baking soda has been found to posses fungicidal properties.
It is recommended for plants that already have powdery mildew to hose down all the infected leaves prior to treatment. This helps to dislodge as many of the spores as possibly to help you get better results.
Use as a prevention or as treatment at first signs of any of the diseases.
1 gallon of water
1 tablespoon of baking soda
1 tablespoon of vegetable oil
1 tablespoon of dishwashing liquid (castile soap)
Mix the ingredients together and add them to a spray bottle. Spray your plants weekly, preferably on overcast days to prevent it from burning the foliage.
Be sure to agitate your sprayer while you work to keep the ingredients from separating. Cover upper and lower leaf surfaces and spray some on the soil. It won't get rid of the fungus on leaves that already have it, but it will prevent it from spreading to the rest of the plant.
Repeat every 5-7 days as needed