The present study was conducted in the Experimental Farm, El-Khattara region, Faculty of Agriculture, Zagazig University, Sharkia Governorate, Egypt during 2009/2010 and 2010/2011 seasons. The study aimed to investigate the response of three barley cultivars (Giza 123, Giza 132 and Giza 2000) to two sowing dates (Nov. 20th and Dec. 20th ) and three seeding rates (30, 45 and 60 kg/fad) under sprinkler irrigation in sandy soils.
The obtained results from this study clearly indicate that the one month delay in sowing to Dec. 20th, adversely affected barley plant growth and development as were expressed in plant height and tillering which were reduced. The development of late sown plants indicated a significant decrease in tiller productivity as was express in a significant decrease in the number of spikes/m2 and as well as in spike development which was expressed in a significant decrease in spike length, number of grains/spike, 1000-grain weight and finally in grain weight/spike. All these adverse effects were finally reflected in the grain, straw and biological yields/fad. Barley cultivars varied significantly in tallness, tillering, spike development and finally grain yield which was always in favor of Giza 132 as it recorded the highest averages of number of spikes/m2, grain yield/fad and harvest index. While Giza 2000 surpassed the other two cultivars in plant height, grain weight/spike, 1000-grain weight and straw and biological yields/fad. Seeding rate gave a clear and consistent significant effect on all growth and yield attributes. Increasing seeding rate from 30 to 45 and 60 kg/fad caused a significant decrease in spike length, number of grains/spike, grain weight/spike and 1000-grain weight, but the grain yield was however increased due to the increase of the number of spikes/m2. The detected significant interactions showed varietal response to date of sowing but the main effects of either seeding rate or sowing date recommended early sowing in Nov. 20th and the use of the highest seeding rate (60 kg/fad) and as well use of Giza 132 in order to maximize the barley grain yield.