NITROGEN FERTILIZATION SOURCE and MICRONUTRENTS IMPACT on CARROT (Daucus carota L.) YIELD Mohamed A. Soliman 1, Mohamed W. M. Elwan 1, Khalid E. Abd El-Hamed 1, and Khaled M. Yousef 2 1 Department of Horticulture, Faculty of Agriculture, Suez Canal University, Ismailia, Egypt 2 Department of Food Science, Faculty of Agriculture, Suez Canal University, Ismailia, Egypt Abstract A field experiment was conducted at the Experimental Research Farm, Faculty of Agriculture, Suez Canal University, Ismailia, Egypt, in fall 2014 to study the effect of two nitrogen soil fertilization sources and foliar application of micronutrients on marketable and total yield of two carrot genotypes. The analysis of main effects of factors under study revealed a significant effect of those factors on carrot yield. Ammonium sulfate gave a higher significant yield compared to ammonium nitrate by 8% and 7.7% for marketable and total yield, respectively. In addition, foliar spraying of micronutrients significantly increased carrot yield by 13.5% and 13% for marketable and total yield, respectively. Genotypes had a significant effect on carrot yield, as genotype Kuroda gave significantly higher yield compared with genotype Nantes by 25.2% and 26.3% for marketable and total yield, respectively. The analysis of interaction effects showed that the highest yield was achieved when genotype Kuroda has been fertilized by ammonium sulfate and sprayed with micronutrients. The study provides interesting results concerning carrot yield. Carrot growers have to give much attention to nitrogen source and micronutrients fertilization as well as genotype selection to maximize their yield. Results Materials and Methods: dc The analysis of main effects of genotypes, nitrogen sources and micronutrients revealed a significant effect of those factors on carrot yield (Table 1). Ammonium sulfate gave a higher significant yield compared to ammonium nitrate by 8% and 7.7% for marketable and total yield, respectively. In addition, foliar spraying of micronutrients significantly increased carrot yield by 13.5% and 13% for marketable and total yield, respectively (Table 1). Besides, genotypes had a significant effect on carrot yield, as genotype Kuroda gave significantly higher yield compared with genotype Nantes by 25.2% and 26.3% for marketable and total yield, respectively (Table 1). Genotypes differed in their percentage of small and defects roots which include deformed- branched- cracked roots as Nantes produced less amount (3%) compared by Kuroda (5%). Also, application of micronutrients reduced the percentage of unmarketable yield from 5% to 3%, while nitrogen source did not show any effect. A field experiment was conducted at the Experimental Research Farm, Faculty of Agriculture, Suez Canal University, Ismailia, Egypt, in September 2014 to study the effect of two nitrogen soil fertilization sources (Ammonium sulfate [(NH4)2SO4] and ammonium nitrate (NH4NO3)) and foliar application of micronutrients on marketable and total yield of two carrot genotypes (Kuroda Improved and Nantes). A drip irrigation system was adopted in this study. The harvest was performed at maturity stage in January At harvest, marketable yield was determined as total yield minus small roots and defects (deformed- branched- cracked) roots. The experiment was laid-out in a Randomized Complete Block Design (RCBD) with three replications. The analysis of interaction effects between genotypes, nitrogen sources and micronutrients showed that the highest marketable and total yield was achieved when genotype Kuroda has been fertilized by ammonium sulfate and sprayed with micronutrients (Table 2). While, the lowest marketable and total yield was attained when genotype Nantes has been fertilized with ammonium nitrate without spraying with micronutrients (Table 2). References Hochmuth, G. J., Brecht, J. K., and Bassett, M. J Nitrogen fertilization to maximize carrot yield and quality on a sandy soil. HortScience, 34(4), ‏