Two field experiments were conducted at two locations; Turkey and
Egypt. Eight recommended spring wheat varieties were planted in 2000/2001
season under two levels of nitrogen fertilizer (70 and 140 kg N/ha) under rain-
fed conditions at the experimental farm of the Faculty of Agriculture, Ege
University, lzmir, Turkey. In 2000/2001 season, the same varieties in addition
to Giza 164 and Sohag 1 were sown under irrigation at the farm of Agriculture
Faculty, Minofiya University, Egypt.
Nitrogen significantly affected all studied traits except kernels per spike.
Genotypes also differed significantly for the studied traits under both nitrogen
levels and over N levels and locations. The varieties x nitrogen interaction was
significant for all studied traits except plant height and grain yield.
A negative grain yield response index (GYRI) for nitrogen under rain-
fed (water stress) was obtained.
The Turkish Basriby variety gave the highest grain yield under both N
levels and either under rain-fed conditions in Turkey or under irrigation in
Egypt. Thus, high yielding varieties under irrigation can possibly be adapted to
conditions of moisture stress.