questions: telling that the leaves of his orange trees are turning yellow and getting drop. so asking the preventive measure for the same. 
 answers: answered mr. konwar that it is due to nitrogen deficiency and sggested to apply 1320 gram of urea, 3000 gram of single super phospate, 668 gram of muriate of potash along with 20 kilogram of farm yard manure in two equal parts. one part to be applied during march - april and the remaining other part in october - november because the plants are in the 4th year stage. however, as a preventive measure, suggested to spray blitox @ 3 gram per litre of water on the leaves right now.