questions: query regarding blight in ash gourd. 
 answers: 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. after that spray one vitamin like- mohaphol 2 ml/liter of water @ 15 days interval up to the end of the season in the evening time in the absence of rain.