2. Materials and methods
Two field experiments were conducted during 2009 and 2010 summer seasons at the experimental farm of the Agricultural Research Center, Sebha branch, Libya. Sebha co-ordinates are latitude: 27◦01N, longitude: 14◦26E and 432 m above sealevel.
The soil at the experimental site is sandy (93.9% sand, 4.0% silt and 2.1% Clay).
Some physical properties relevant to irrigation in the experimental site are given in Table 1.