This study was carried out during two successive seasons, 2012 and 2013 in a private orchard in Barshom vallage located at El-Kalubia Governorate Egypt. Washington Navel Orange trees (Citrus Sinensis) budded on sour orange rootstock (Citrus aurantium, L.) were 7-years-old and planted at 5 x 5 meters under basin irrigation system. This investigation aimed to study the effect of selenium (Se) levels (0, 20, 40, 80 and 160 ppm) as foliar spray on growth, yield, fruit quality, leaf mineral content and enzymes activity of Washington Navel orange trees. The obtained data showed that, selenium had a significant promotive effect on growth, yield, fruit quality, leaf mineral content and enzymes activity of Washington Navel orange trees. Results indicated that treatment of Se at 40 ppm gave the highest significant results, whereas, treatment 160 ppm gave the highest fruit selenium content.

This study was carried out through two consecutive seasons 2016 and 2017 to investigate the effect of spraying with some antioxidants on vegetative growth, yield, fruit quality and nutritional status of twelve years old 'Navel orange᾿ trees grafted on sour orange rootstock and grown in a private orange orchard in Qalubia Governorate, Egypt cultivated in a silty clay loam soil. This experiment involved three antioxidant materials named (salicylic acid, citric acid and folic acid) and each one spraying by three levels of each of with (250, 500 and 1000 ppm) from each salicylic, citric and folic acid plus control treatment so the experiment included ten treatments. Selected trees were sprayed three times in March, in May in July by aqueous solution of salicylic acid, citric acid and folic acid until the point of runoff. The highest values of vegetative growth were obtained by spraying by 500 ppm salicylic acid, 1000 ppm citric acid and 500 ppm folic acid. Regarding to yield, results pointed out that the foliar spraying with 500 ppm salicylic acid, 500 ppm citric acid and 250 ppm folic acid gave the highest values of yield. Treatments of 500 ppm salicylic acid, 250 ppm citric acid and 250 ppm folic acid gave the highest values of physical and chemical fruit properties. In respect to nutrients content, the highest values of macronutrients were obtained by spraying of 250 ppm folic acid, while that spraying by 1000 ppm salicylic acid and 250 ppm folic acid gave the highest values of micronutrients. Therefore, using treatment 500 ppm salicylic acid may be recommended from economical point of view and as good treatment for enhancing Navel orange growth, yield, fruit quality and nutritional status especially under old citrus orchards.

of some types and levels of nitrogen on vegetative growth, mineral content, yield and fruit quality of 5 years old Murcott tangerine trees (Citrus reticulate, Blanco.) budded on Volkamer lemon rootstock and cultivated in "Hegazi orchard" located in Cairo to Alexandria desert road, Egypt at 2.5 × 5m apart. The experiment contain two factorsThe first factor was added nitrogen at two levels i.e., 90 and 120 kg actual N/fed while the second factor was added 5 types of nitrogen i.e., 100% Mineral nitrogen fertilizer (MNF), 50% Commercial plant residues compost (CRC) +50% (MNF), 50% Bagasse compost (BC) +50% (MNF), 50% Waterhyacinth compost (WHC) +50% (MNF) and 50% Chicken manure (CHM) +50% (MNF). A great increase in fruits number, fruit weight, yield, pulp weight, juice weight, pulp: fruit %, juice: pulp %, ascorbic acid and (N, K, Zn leaf content) were recorded by120 Kg actual N/fed. Generally, 50% WHC + % 50 MNF and 50 % CHM + %50 MNF gave the highest values of most characters followed closely by control. Therefore, it could be recommended by fertilizing young Murcott trees with (120 Kg actual N/fed) added as (50%WHC + %50 MNF) or (50 % CHM + %50 MNF) enhanced yield, fruit quality and it is an effective method for get rid of Water hyacinth weed by easier way.

T O EVALUATE efficacy of fertilizing with different combinations of organic fertilizers on yield, fruit quality and nutritional status of "Wonderful" pomegranate trees, a field experiment was carried out in "Hegazi farm" located in Cairo to Alexandria desert road, Egypt. during three growing seasons 2016, 2017 and 2018 on nine years old pomegranate trees cv. 'Wonderful' growing in sandy loam soil under 62% shading. Nitrogen requirements were added from different combinations of commercial organic fertilizers such: Compost (COM), Chicken Manure (CHM), Cattle Manure (CAM) and Mineral Fertilizer (MF) by the rate 40 kg actual N fed-1 with or without humic acid addition. The experiment consists of ten treatments spread in a randomized complete block design with five replicates. Fertilizing with (50% (CHM)+ 50% (COM)), (50% (COM) + 50% (CAM) and (33.3% (CHM) + 33.3% COM) + 33.3% (CAM) + humic) enhanced vegetative growth, yield. Fertilizing with (50% (CHM) + 50% (COM) + humic) and (33.3% (CHM) +33.3% (COM) +33.3% (CAM) + humic) improved fruit physical properties like (arils weight, juice weight and juice volume). Fertilizing with, (50% (COM) + 50% (CAM) + humic) gave the highest content of TSS%, TSS/acid ratio & ascorbic acid and least content of acidity. So it could be recommended by, fertilizing "Wonderful" pomegranate trees by one of these treatments (50% CHM +50% COM + humic), (50% COM +50%CAM+ humic) and (33.3% CHM+33.3% COM+33.3% CAM +humic) by the rate of 40 kg actual N fed-1 to improve yield, fruit quality and nutritional status.

Nanoparticles (NPs), especially from micronutrients, are recently motivated for replacing their common mineral counterparts. To evaluate their comparative efficacy, this investigation was conducted to estimate the impact of foliar application of zinc through different sources on productivity, fruit quality and improve marketable fruit of "Wonderful" pomegranate trees. The field experiment was performed during two seasons (2017 and 2018) on sevenyear old pomegranate trees "Wonderful" cv., cultivated in a private "Hegazi" farm located at 57 km. from Cairo on the road to Alex., Egypt. Four sources of zinc named "Zinc Sulphate, Zinc mannitol complex, Bio-Nano zinc (Bio Zn NPs) and Zinc Oxide nanoparticle (ZnO NPs) with four rates from each other were sprayed twice (the first before one week from full bloom and the second after a month from the first). So the experiment included seventeen treatments in a sample study spread in a randomized complete block design by five replicates. Results explicated that the greatest significant values of fruit set% were recorded by Bio Nano Zinc (Bio Zn NPs) treatments especially (400 ppm Bio-Nano Zinc (Bio Zn NPs)). Spraying with (3000, 4000 ppm Zn mannitol complex) and (300, 400 ppm Bio-Nano Zinc (Bio Zn NPs)) showed significantly the greatest values of productivity, improves marketable fruits and fruit quality of "Wonderful" pomegranate trees. So it could be recommended by spraying "Wonderful" pomegranate trees by 3000 ppm Zinc mannitol complex or 300 ppm Bio-Nano zinc (Bio Zn NPs). Another important point is that the application of Bio Zn NPs fertilizer at around 10% from the commercial dose of zinc sulphate resulted in the same results without any change in the productivity, further researches are needed to study a further low level of Zinc Oxide nanoparticle (ZnO NPs) below (100 ppm Zinc Oxide nanoparticle (ZnO NPs)) which may be improving yield and fruit quality.