To control powdery mildew, use 500g of pounded neem leaves soaked in 5 litres of water for 24 hours. Spray weekly. Another way, mix 1 tablespoon baking soda with 1 tablespoon of vegetable oil and 4 litres water, then add half a tablespoon of soap and stir. Spray immediately and reach coverage of all leaves. Spray twice, this is once per two week interval.

Spray hexaconazole fungicide.