Two field experiments were conducted in 2006/2007 and 2007/2008 seasons at Zeenat al Sahra farm of Royal Court Affairs, Nejd region, Governorate of Dhofar, Sultanate of Oman to study the effect of sowing date on some yield attributes of wheat.
The results in both seasons and over them revealed that delaying sowing dates from 1 November to 30 November caused significant reduction in plant height, spike length, number of spikelets/ spike, number of spikes /m2, number of grains / spike, 1000- grain weight, grain yield and biological yield in both studied seasons and over them, however , straw yield in the 2006/ 2007 season only not effect significantly by delaying sowing dates.
Delay sowing dates from 1 November to 30 November caused reduction in grain yield/ fad by 41.71 % , 27.10 % and 35.68 % in first season, second season and over them, respectively.
Grain yield / fad showed positive and significant correlation with the number of grains /spike, number of spikes/m2 and 1000 grain weight
The most positively correlated component to grain yield was spike length which had the highest direct relationship with grain yield under the first and third sowing dates.
Spike length, number of grains / spike and 1000- grain weight contributed to together 71.78%, 58. 68% and 61.44% of the total grain yield variation under the three sowing dates, 1 November, 15 November and 30 November, respectively.
The highest indirect association to grain yield was due to spike length through 1000- grain weight, under the first sowing date.
Conclusively, from these results it could be concluded that dealing sowing date caused significantly reduction in grain yield of wheat, under Najd desert condition.