Two field experiments were conducted in 2003/2004 and 2004/2005 seasons in Gelbana village, El-Kantra Shark, Sinai to study the effect of three sowing dates (30 September, 15 October and 5 November) and two harvesting dates ( 180 and 200 days after sowing) on productivity of five sugar beet varieties  ( Top, Kawemira, Gloria, Pleno and Farida ) under sprinkler and drip irrigation systems. Sowing sugar beet under sprinkler or drip irrigation systems, at middle October recorded the highest root fresh weight/plant, root diameter and root length. Also, when sugar beet sown on 15 October, root and sugar yields/fed attained the highest values. On the other hand, the latest sowing date, namely 5 November produced the highest values of top fresh weight/plant, sucrose %, purity % and top yield/fed. Delaying harvest sugar beet from 180 till 200 days after sowing improved significantly the individual root characters and juice quality, as well as increased significantly root and sugar yields/fed. That held true under both irrigation systems in the two growing seasons. It was proved that sugar beet varieties differed under each irrigation system, where, Pleno cv. gave the highest values of root and top fresh weight/plant and root diameter under sprinkler irrigation, while Kawemira and Top cvs. were the best under drip irrigation. Concerning root and sugar yield as well as juice quality, Pleno, Kawemira and Top  cvs. were the best under both irrigation systems.