Two field experiments were carried out at El-Sirw Agriculture Research Station, Damietta Governorate in 1998/99 and 1999/2000 seasons to study the effect of five nitrogen rates i.e. 0, 30, 50, 70 and 90 kg N/fed (as soil fertilization) and five of urea concentrations i.e. 0, 1, 3, 4 and 5% urea (as foliar application)on growth, yield components, yield and quality of sugar beet in newly reclaimed soils (saline soil). The experiments were laid out in strip block design with three replications.
The obtained results showed that average values of root length, root fresh weight, top yield/fed, root yield/fed and root α-amino nitrogen content were significantly increased with increasing nitrogen fertilizer rate (as soil fertilization) in both seasons. Applying nitrogen fertilizer at the rate of 90 kg N/fed. gave the highest values of the previously mentioned traits in both seasons, while the highest sugar yield/fed was recorded with 70 kg N/fed.
On the other hand, sucrose percentage and purity percentage significantly decreased with increasing nitrogen fertilizer rate up to 90 kg N/fed in both seasons.
The obtained results indicated that average root length, root fresh weight, top yield/fed, root yield/fed, sugar yield/fed and root α-amino nitrogen content were significantly increased as urea concentration increased in both seasons. Foliar application of urea at 5% concentrate gave the highest values of mentioned previously characters in both seasons. On the contrary, sucrose percentage and purity percentage significantly decreased with increasing urea concentration up to 5% in both seasons.
The obtained results illustrated that all the previously mentioned traits significantly affected by the interaction between nitrogen fertilizer rates (as soil fertilization) and urea concentration (as foliar application) in both seasons. Applying nitrogen fertilizer at the rate of 70 kg N/fed and sprayed with urea 5% concentration gave the highest root yield and sugar yield/fed in both seasons.