الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
thirty trees of uniform size and vigour, 20 years old, badded on sour orange and planted at 4x4 meters a part were selected for this study from the citrus orchard which contained 250 trees/fed. ammonium sulphate fertilizer (20. 5 % n) was used as nitrogen source for soil application in five nitrogen rates (0, 120, 180, 240 and 300 kg n/fed) and fe as fe edta at 300 ppm, mo as ammonium molybdate at 100 ppm as foliar spray at rate of 600 l/fed were applied, so the experiment in each season contained 10 treatments replicated 3 times in complete randomized blocks design. in all treatments, nitrogen rate was divided into equal three doses to be applied at first of march, middle of may and middle of july in both seasons. results obtained could be summarized as follows: i- yield and fruit quality: all treatments used significantly increased the yield, number of fruits per tree, fruit weight and size than the control. trees treated with any different level of n fertilization and sprayed with fe+mo gave a higher yield and number of fruits than the other treatment under study. foliar application of fe+mo with any level of n fertilization under study increased the fruit weight and size than the other treatments used or untreated ones. all treatments increased both pulp and rind weight of the fruits than the control. moreover, fe+mo application with n fertilization levels gave a more pronounced effect in this respect. fe+mo application with any levels of n fertilization under study significantly increased fruit juice volume than the other treatment or untreated trees. n fertilization levels alone or combined with fe+mo increased vitamin c content in fruit juice than the untreated one. all n fertilization treatments used alone or combined with fe+mo gave significant increase in total sugar and total soluble solids than the control. n fertilization treatment combined with or without fe+mo reduced the total acidity in fruit juice during the two seasons under study. ii- juice, pulp and pulp remainder nutrient content: increasing n fertilization levels with or without fe+mo increased n content in both of juice and pulp remainder and decreased p and k. increasing n fertilization levels with or without fe+mo increased fe content in juice and pulp remainder and increased mo. increasing n fertilization levels increased significantly no3 and no2 in fruit pulp. whereas, applied the foliar application of fe+mo to the same n fertilization rates under study decreased no3 and no2 content in fruit pulp. iii- leaf nutrient content: n fertilization levels with or without fe+mo increased n content in the leaves and decreased leaf p and k content during the two seasons under study. foliar application of fe+mo with any n-fertilization levels significantly increased iron and molybdenum conten in leaves than the untreated trees. increasing n fertilization levels increased no3-n and no2-n in the leaves. whereas, treated the trees under the same n fertilization levels under study with fe+mo as foliar application decreased leaf no3 and no2 content. conclusion from this study, it can be concluded that foliar application of fe + mo with n fertilization treatments under study increased yield of balady mandarin trees due to their effect on increasing the fruit number per tree. moreover, the effect of these treatments on the content of npk and fe, mo in leaves were more pronounced similarly, with total sugars, total soluble solids and vitamin c whereas, the foliar application of fe + mo decreased the total acidity in fruit juice, no3 and no2 nitrogen content in fruit pulp and leaves so induced good quality for fruits