A field experiment was conducted at the farm of Dept. of Field Crop Sciences, College of Agriculture, University of Baghdad, during 2008-2009 and 2009- 2010. That was to study performance of growth, yield and quality of bread wheat under sowing dates and irrigation intervals for IPA 99 variety. A randomized complete block design with three replicates with a split-plot arrangement was used. The sowing dates (November 20, December 5 and December 20) occupied the main plots, while irrigation intervals (2, 3, 4, and 5 weeks) occupied the sub plots.
Results showed superiority of the sowing date November 20 in giving the highest averages of number of days from sowing to 100% anthesis (118.34 – 105.67 days), Chlorophyll Concentration in flag leaf (48.75 and 49.66), grain yield(5.03 and 4.82 t. ha-1), during the two seasons respectively. The treatment of 2 – weeks irrigation was superior by giving the highest averages of spike Length (11.63 and 11.38)cm, number of spikelets spike (20.13 and 19.98). Grain yield (5.20 and 4.98 t. ha-1), and minimum averages of protein 12.34% and 11.59% and moist gluten percentage 32. 50% and 31. 07 % during the two studying seasons respectively. There was a significant interaction between irrigation intervals and sowing dates. The combination of 2-weeks irrigation interval with sowing date November 20 gave the highest of number of days from sowing to 100% anthesis(119.67 – 107.33 days), Chlorophyll Concentration in flag leaf (50.38 and 51.30), grain yield(5.71 and 5.49 t. ha-1), during the two seasons respectively.
The treatment of 5 – weeks irrigation intervals with sowing date December 20 gave less averages of spike Length, number of spikelets spike, grain yield and the maximum averages of protein and moist gluten percentage during the two studying seasons respectively. Can be conclude that delay of planting with increase irrigation intervals led to decreased yield and increase protein and moist gluten percentage. Therefore can be recommend to Sowing this cultivar during in 20 Nov. under 2-weeks irrigation interval to obtain higher growth and yield. To attain best quality advise to delaying sowing with increase irrigation intervals