ABSTRACT
Water stress is considered as one of the major factors responsible for
reducing sugar beet crop productivity. A field trial was conducted at Sidi
Salem district private farm (31° 07' N latitude, 30° 05'E longitude), Kafr El-
Sheikh governorate, north Nile Delta, Egypt, for two successive seasons at
2018-2019 and 2019-2020, to find out the effects of water stress treatments
(2, 3 and 4 weeks of irrigation intervals) on the vegetative growth, and juice
quality of five sugar beet varieties, which were three multigerm (Marwa-
KWS, Farida, and Nabila), and two monogram (Amaldi and Xanada).
Treatments were conducted in a split-plot design with three replicates. The
most important results obtained showed that delayed irrigation intervals (4
weeks) led to a marked decrease in, root diameter, root weight, root yield in
both seasons. Meanwhile, increase root length, sucrose%, extractable
sugar%, and sugar yield in both seasons. The drought-tolerant variety
(Marwa-KWS) showed significant differences compared to the control.
However, drought-sensitive variety (Nabila) was markedly affected even at
the water stress (4 weeks). Results indicated that varieties (Marwa KWS,
Farida, and Amaldi) appeared the best performance under the longest
irrigation intervals (4 weeks) for root and sugar yields and their components.
chlorophyll a and b, carotenoids, significantly decreased with delay
irrigating days, meantime increase antioxidant enzymes under stress
conditions.