Question: query regarding management of fruit rot and drop in bottle gourd. 

Answer: --at first spray and apply  borax 6 gram/liter of water 2 times @ 1o days interval in the evening time near the root zone. continue one vitamin like- mohaphol/sagorika/biovita 2 ml/liter of water @ 15 days interval up to the end of the season in the evening time in the absence of rain.