Eight promising lines and two commercial varieties were grown at two sowing dates under two irrigation regimes in two successive seasons of 2002/2003 and 2003/2004 (8 environments). Highly significant differences among genotypes, planting dates, irrigation regimes, and significant G x E interactions were obtained for all the studied traits.
Delaying sowing date and water stress reduced all studied traits. The highest grain yield / feddan were obtained from genotypes F10 (129), Giza 164 and Giza 168 which recorded 15.0, 15.8 and 16.1 ardab/ feddan, respectively), these previous genotypes had late heading date.
The regression coefficient was highly significant and positively correlated with the mean performance for most studied traits, indicating that low yielding genotypes were generally stable while high yielding ones were rather responsive.
However, genotypes H109, Giza 164 and Giza 168 exhibited stability and high yielding. On the other hand, the bi values for genotypes H109, Giza 164 and Giza 168 were > 1, this indicating that these genotypes are more adaptive for highly favorable environments.
The results of path-coefficient analysis under recommended and late sowing date, showed strong positive direct effects of the No. of spikes / plant and spike length and moderate one of 1000-kernel weight on yield for those studied genotypes of wheat.
Moreover, the direct effect of days to heading, No. of spikes/ plant, spike length and 1000-kernel weight on yield decreased from recommended to late sowing date.