Saleh,, M., Abd EI-Kader, A. (2004). EFFECT OF SLOW RELEASE NITROGEN FERTILIZERS ON LEAF MIN REAL CONTENT, YIELD AND FRUIT QUALITY OF WASHINGTON NAVEL ORANGE TREES. Journal of Plant Production, 29(10), 5813-5820. doi: 10.21608/jpp.2004.238866
M. M. S. Saleh,; A. A. Abd EI-Kader. "EFFECT OF SLOW RELEASE NITROGEN FERTILIZERS ON LEAF MIN REAL CONTENT, YIELD AND FRUIT QUALITY OF WASHINGTON NAVEL ORANGE TREES". Journal of Plant Production, 29, 10, 2004, 5813-5820. doi: 10.21608/jpp.2004.238866
Saleh,, M., Abd EI-Kader, A. (2004). 'EFFECT OF SLOW RELEASE NITROGEN FERTILIZERS ON LEAF MIN REAL CONTENT, YIELD AND FRUIT QUALITY OF WASHINGTON NAVEL ORANGE TREES', Journal of Plant Production, 29(10), pp. 5813-5820. doi: 10.21608/jpp.2004.238866
Saleh,, M., Abd EI-Kader, A. EFFECT OF SLOW RELEASE NITROGEN FERTILIZERS ON LEAF MIN REAL CONTENT, YIELD AND FRUIT QUALITY OF WASHINGTON NAVEL ORANGE TREES. Journal of Plant Production, 2004; 29(10): 5813-5820. doi: 10.21608/jpp.2004.238866
EFFECT OF SLOW RELEASE NITROGEN FERTILIZERS ON LEAF MIN REAL CONTENT, YIELD AND FRUIT QUALITY OF WASHINGTON NAVEL ORANGE TREES
1Pomology Depart. National Research Center, EI-Behos st., Dokki, Cairo
2Soils and Water Use Depart National Research Center, EI-Behos st., Dokki, Cairo
Abstract
Washington navel orange trees grown in clay loam soil were fertilized with urea-formaldehyde (UF) as a slow release nitrogen fertilizer during two successive seasons 2002 and 2003 in a private orchard located in Banha, Kalubia governorate, Egypt.
Trees were fertilized with urea at 1000 gm N/tree divided into three equal doses as control treatment, while urea-formaldehyde was used at three doses 1000, 750 and 500 gm N/tree each of them added either as one application in March or divided into two equal applications added in March and June.
Results indicated that N, P and K contents in the leaves did not affect significantly by different treatments. In this respect, UF treatments enhanced nitrogen percentage comparing with urea treatment. So, UF at 1000 gm N/plant raised N content in the leaves comparing with the other treatments. On the other hand, fertilizing trees with UF at 500 gm N/tree either as one or two applications raised potassium content than the other treatments.
Concerning the effect on yield and fruit quality, the data reveal that all treatmerts had a significant effect on number of fruits per tree since; using UF at 500 gm N/tree significantly increased this parameter than the other treatments and gave the higher values especially when added as one application and resulted in highest yield weight/tree. On the other hand, no significant differences were detected between treatments on fruit weight, peel thickness, fruit juice content, total soluble solids, acidity and ascorbic acid in fruit juice, although the higher UF doses specially 1000 and 750 gm N/plant tended to increase peel thickness.
Thus, it seems that fertilizing Washington Navel orange trees with urea-formaldehyde at 500 gm N/tree as one application added in March is the suitable treatment under conditions of this study.