Effect of Plant Densities on Growth, Yield Components and Quality of Some Sunflower Cultivars ( Helianthus annuus L.)

A field experiment was conducted for two consecutive seasons [2008][2009][2009][2010] at AL-Quba location in the west north region of Mosul city at Nineveh region to study the effect of planting density on the performance of two sunflower cultivars; namely, Mehran and Sunbred.The plants were sown at four planting densities: 41666, 47619, 55555 and 66666 plants.ha-1 , respectively.The data were statistic analyzed by using factorial experiments in randomized complete block design with three replications.The results indicated that the stem diameter, leaf area, head diameter, number of seeds per head, weight of thousand seed, hulls, fertility percent, harvest index and seed yield per plant, oil and protein content of the seeds decreased with increasing plant density.Increasing plant density cases significantly increase in seed yield per unit area and oil, protein yield.The differences between the two cultivars cultivation were significant in all the studied characters, except protein yield in 2008-2009 season, protein content of the seeds in 2009-2010 season.The higher seed yield of Mehran cultivar was associated with higher flower disc diameter and greater number of seeds per flower disc.Based on what has been presented in this study, could be concluded that the plant density of approximately 66666 plants.ha-1 is the optimum for sunflower crop cultivation, and Mehran cultivar proved be more promising than Sunbred cultivar.