questions: asking about control of yellowing of leaf in blackgram. 
 answers:  spray npk 19:19:19 10 gram/liter of water 3 times at 5 days interval in the evening time in the absence of rain.after that 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.