Field trials were carried out to study the response of navel orange to optimized nutrition. The field trials were conducted during 94/95, 95/96 and 96/97 seasons in Tanta, Kafr El-Zayat, Bassioun and Kotour districts at Gharbia governorate.                 The first season of all farms was considered as control and the amounts of fertilizers were applied according to the farmer practices. During 95/96 and 96/97 seasons, supplementary amounts of NPK were applied in soil together with spraying chelated micronutrients on leaves for correcting nutrient deficiency. Application of NPK, Fe, Mn and Zn led to both improvement of  leaf nutritional status and considerable increase of yield in second and third seasons ranged between 25-60  and 52-70 % over  check season, also, the average yield of farms improved from 42 % less than governorate average  in 94/95 to excecd governorate average by 9 % in 96/97.                 In addition, leaf analysis indicated that correction of micronutrients deficiency by foliar application led to increase macro and micronutrients concentration in leaves.