TWO field experiments were carried out during 2016/2017 and 2017/2018 seasons at the agricultural experimental station farm of Water Studies & Research Complex (WSRC), National Water Research Center, located in Abu-Simbel, Toshka, at the most southern part of Egypt, about 1300 south from Cairo and 280 Km from Aswan (latitude of 22 o.49- N, longitude of 28 o.58- E) Aswan Governorate, Egypt. These trials aimed to find out the effect of water stress rates (60%, 80% and 100% of irrigation water requirements (IWR). on yield, yield components and quality of sugar beet varieties namely Oscar poly, Farida, and Universal. Randomized complete block design, in Strip Plots arrangement, with three replications was used.
Results indicated that water stress treaments were significantly influenced all the studied characters. Also results revealed that irrigated sugar beet plants with 100% of IWR recorded the highest root length, diameter, weight, sucrose %, extractable sugar % and extractability % as well as root and sugar yields, while it gave the lowest mean values of impurities and sugars lost to molasses percentages.
Also results showed that the differences among the examined varieties were significant with respect to all studied traits. Results indicated that variety of Oscar poly surpassed the other two varieties in root yield and its yield components, However, Universal variety surpassed the other varieties in sucrose, extractable , extractability percentages and sugar yield.
Under conditions of Toshka region, the results suggested that planting Universal beet variety, with 100% of the irrigation water requirement can be recommended to produce the best quality as well as the highest root and sugar yields/ha.