This study was conducted at the experimental farm of Field Crops Science Department , College of Agriculture , University of Tikrit , during the Autumn season of 2003 and Spring season of 2004 to study the effect of four nitrogen fertilizer levels ( 0 , 60 , 120 and 180 kg N/ha) with three rows spacing (20 , 30 and 40 cm) on the growth traits, yield and it's components of Rape seed ( Brassica napus L. var. pactol).The R.C.B.D with three replications was used in this experiment.
The results indicated that the Nitrogen fertilizer applications significantly affected on first branch height (cm) , leaf area (cm2/plant) , namber of days from sowing to 100% maturity, in both seasons , while number of secondary branches /plant in autumn season only. No. of days from sowing to 50% flowering in spring season were found to be significant .
The rows spacing affected significantly on most of the studied traits, The row spacing 30cm gave the highest rate for leaf area (cm2/plant) in autumn season , while the data showed that 40cm row spacing gave significant effects for No. of secondary branches/plant in Autumn season and No. of primary branches/plant and leaf area (cm2/plant) in spring season. A significant interaction were found between Nitrogen fertilize and rows spacing for all of the studied characters .