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 on sour orange rootstock 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 spraying three times (at the beginning of the growth cycle in March, just after fruit setting in May and just after June drop 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 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 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 250 ppm folic acid, while that spraying 1000 ppm salicylic acid and 250 ppm folic acid gave the highest values of micronutrients. Therefore, using treatments 500 ppm salicylic acid, 500 ppm citric acid and 250 ppm folic acid may be recommended from economical point of view and as good treatments for enhancing Navel orange growth, yield, fruit quality and nutritional status especially under old citrus orchards.

Various percentages of citric acid [0.05, 0.1, 0.15 and 0.2%] were blended with the oil (w/v) before the bleaching of either soybean oil (SOO) or sunflower oil (SUO) to rise the performance efficiency of bleaching earth. Afterwards, activated bleaching earth was added to these oils for bleaching them at 1% level. Also, the same clay was used at 2% level for bleaching the above mentioned oils without us-ing citric acid as a reference. The study revealed that better result for raising the bleaching efficiency of SOO was obtained with 0.15% citric acid. Whilst, 0.1% cit-ric acid gave the best result pertaining the bleaching efficiency of SUO. Also, the data showed high reductions in the values of peroxide number, soap, conjugated dienes and trienes for the bleached oils with the increasing percent content of citric acid. While, the acidity values of the bleached oils (SOO and SUO) slightly in-creased with increasing citric acid percentages. On the other hand, using of citric ac-id at the ratios of 0.15 and 0.2% gave almost the same values in the bleaching effi-ciency of SOO. While, using of citric acid at the ratios of 0.1 and 0.15% gave nearly the same results of bleaching efficiency of SUO. Also, the data indicated that using of citric acid caused somewhat no changes in the fatty acid composition or their oxi-dative stabilities in the bleached oils. Therefore, it can be concluded that the reduc-tion in the color of sunflower and / or soybean oils up to a levels of 33.3 and 36.7% is attainable by using either 0.1 or 0.15% citric acid prior to the bleaching step to de-crease the imported content from bleaching earth to Egypt