الفهرس 
Water shortage in Arab RegionOnly 14 pages are availabe for public view
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Abstract
A field experiment was conducted in newly reclaimed sand soil to find out the most efficient combination between irrigation system and deficit irrigation management can be used for date palm trees “Zaghlol cultivar”.
Results revealed that the average water requirements of date palm trees gradually increased from 1504, 1279, 1128 and 978 for drip to 2522, 2143, 1891, and 1639 m3/fed-Season for bubbler irrigation system in combination with 100, 85, 75 and 65% deficit irrigation treatments respectively. Similar trend was also observed comparing with flood irrigation system with 100 % irrigation deficit treatment where the water requirements increased from 1504 for drip and 2522 for bubbler to 4083 m3/fed-Season for flood irrigation system. Data indicated that EC1:5 in dS/m gradually increased with decreasing deficit irrigation levels from 100 to 65% and with increasing soil layer depth to 60-90 cm either in parallel or perpendicular direction of drip or bubbler irrigation lines. While opposite results were observed for soil moisture distribution. Results showed an evident decrease in crop yield as affected by water stress associated with decreasing deficit irrigation treatments from 100 to 85, 75 and 65 % by about 167, 155, 153, 151 for drip and 181.5, 168, 172 and 169 kg/Tree for bubbler irrigation systems. Data revealed that water use efficiency increased from 9.55 for 100% DI to 10.4, 11.7 and 13.2 for drip and from 6.19 for 100% DI to 6.74, 7.82 and 8.87 for bubbler irrigation systems with decreasing deficit irrigation levels to 85, 75 and 65% respectively. from the above mentioned results, it could be concluded that the best method for managing irrigation of date palm trees ”Zaghloul cultivar” in the study area is irrigation using bubbler system with 75% sustained deficit irrigation. This combination treatment gave an acceptable yield about 172 kg/tree using about
1891 m3 irrigation water per feddan or 22 m3/tree-season and saving a substantial amount of irrigation water reached to about 25 % leading to an encouraging value of water use efficiency by date palm trees about 7.82 kg/m3.
Key words: Drip and bubbler Irrigation, Water use efficiency, Deficit irrigation, Date palm.