Two field experiments were carried out during 2001 and 2002 growing seasons. to study the eHect of surge irrigation. under three different irrigation intervals
7. 14 and 21 days, on sunflower yield, advance time, water applied rNA), crop water
consumptive use (CU). water application efficiency 0NAE) and water utilization
efficiency (WUtE), in clayey soil at North Nile Delta in Egypt. Four irrigation
treatments were implemented. as follows: (1) continuous irrigation (control). (2) surge
irrigation with cycle ratio of 0.5 (10 min .. on-10 min. Off). (3) surge irrigation with cycle
ratio of 0.4 (10 min. On-15. Off). (4) surge irrigation with cycle ratio of 0.33 (10 min.
On-20 min. Off). Results indicated that. the advance tune rates for surge flow
technique. were highly shorter i.e. faster than rates under continuous flow. Data
revealed that surge irrigation with 0.33 cycle ratio resulted in a significant reduction in
total applied irrigation water. with an average of 27.7, 38.3 and 38.0% less than
continuos watering at irrigation intervals 7, 14 and 21 days respectively. Data also
showed that. surge irrigation treatment with cycle ratio of 0.33 (10 min. On-20 min.
Off) recorded the lowest values of C.U. 42.9, 37.75 and 31.05 em for 7. 14 and 21
days intervals respectively. On the other hand. the highest WA values 45.5. 41,4 and
33.3 were resulted from the continuous irrigation (control) applied at 7. 14 and 21
days respectively. The results revealed that surge irrigation treatment with cycle ratio
0.33 (10 min. On-20 min. Off), recorded the highest values of 0NAE) 84.2 and 91.S
for 7. 14 and 21 days respectively. In addition surge irrigation treatments recorded the
highest values of WUtE.