Pakistan is facing an acute shortage of edible oil. In order to overcome the prevailing situation, there is a dire need to increase per acre yield of non-conventional oilseed crops. Plant density and nitrogen fertilizer levels are among factors affecting sunflower yield and seed oil percentage. The interaction between plant spacing and N rate significantly affected seed and oil yields. In this context, the OILCROP-SUN model has been tested with sunflower and results indicated that achene yield of sunflower hybrid cultivar among various planting densities was related to their photosynthetic...