Question: query regarding control of powdery mildew in pumpkin. 
Answer: 
pluck the excessively affected leaves from the plants and burn them in a separate place out from the field. spray copper oxychloride (blitox-50/ blue copper) 3 gram per liter of water 3 times at 5 days interval in the evening time in the absence of rain.for more production - spray one vitamin like mohaphol/ sagarika/biovita 2ml/liter of water at 10-15 days interval in the evening time at flowering and fruit initiation stage.