Blight is a fungal infection that affects plants in high moisture situations. It is hard to contain and spreads to the rest of the plant. It commonly affects tomatoes. Try not to plant them in the same spot year after year. Baking soda helps create an alkaline environment. Make a spray and cover the whole affected plant. Cover both sides of the leaves.

Mix:

• 3 tablespoons baking soda, 1 gallon of water, 1 tablespoon vegetable oil, and 2 drops dish soap.
• Spray every 3 weeks until clears, increase to 3.5 tablespoons if the mildew/blight continues to grow.