Abstract: Objective Two field experiments were conducted during 2008-2009 and 2009-2010 seasons at Zankalon Research Station,El-Sharkia Governorate,Egypt to study the effect of different levels of irrigation and nitrogen fertilizers on sugar beet yield,quality and some water relations. Method Experiments were conducted in split plot design with four replicates using three irrigation ( Ⅰ1.Ⅰ2 and Ⅰ3 with 60,80 and 100% of field capacity,respectively) and three N fertilizer (N1,N2 and N3 with 50,70 and 90 kg N/fed,respectively) treatments.ResultThe treatment Ⅰ1 achieved the highest root,sugar yield and root diameter,followed by Ⅰ2,while treatment Ⅰ3 recorded the lowest values.On the other hand,root length and sucrose % significantly decreased with increasing irrigation levels.Increasing N fertilizer up to 90kg N/fed (N3) increased root length,root diameter,and root and sugar yield significantly,while decreased sucrose %.The results showed that both the irrigation and N fertilizer treatments had no significant effect on purity %.The amounts of applied water in three treatments was recorded as 3579.7,3042.0 and 2504.0 m2/fed,respectively,and the seasonal water consumptive use values were recorded as 58.12,52.06 and 47.29 cm,respectively.Water use efficiencies (WUE) for root yield were calculated as 15.86,13.78 and 13.35 kg roots/m3 water,while they were 2.73,2.61 and 2.56 kg sugar/m3 water for sugar yield,for treatment Ⅰ1,Ⅰ2 and Ⅰ3,respectively.Increasing N fertilization level increased actual water consumpfive use and WUE for root and sugar yields.Average seasonal crop coefficient value of 0.87 was obtained for sugar beet crop grown at East Delta region.ConclusionIt may be recommended to use the empirical values of Kc in order to calculate consumptive use at East Delta region.