questions: query regarding not getting the flower and fruits in bottle gourd. 
 answers:  spray 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.
spray npk 19:19:19 10 gram per liter along with 6 gram micronutrient mixture per liter  of water 3 times at 15days interval in the evenig time in the absence of rain.