Abstract
The greatest challenges facing the improvement of agriculture programs under arid and semiarid environment are those involving the provision of water. Thus, field experiments have been carried out in a splitplot design at the Agricultural Research Station, Faculty of Food and Agricultural Sciences, King Saud University. The experiments included 20 treatments, four wheat genotypes, (Yecora Rojo, West bread, KSU 102 and KSU 105) and five irrigation schedules (50, 100, 150, 200 mm) of cumulative pan evaporation CPE, as compared to traditional irrigation methods used by many farmers (weekly irrigation). The total amount of water supplied over the growing season was calculated. The data obtained clearly indicated that a gradual decrease in most of the yield and yield component characters were in line with decreasing irrigation schedules. The results also showed that no significant differences were found between irrigation schedules at 50 mm, followed by 100 mm CPE. Finally, we can conclude that at least 20% of water irrigation could be conserved to achieve high grain yield.