This research was conducted to determine the effect of different doses of plant activator (Megamineral) on yield and yield components of sorghum-sudangrass hybrid (Sorghum bicolor xSorghum sudanense) cultivars under Sanliurfa ecological conditions at Harran university Eyyubiye experiment station in one harvesting the second crop 2014-2015 growing season. In the research total of 2 Sorghum-Sudangrass hybrids have been used and it has been planned according to split split parcels in random blocks with three replications and 5 megamineral applications (0, 250, 500, 750, 1000 kg/da) (each application doses was applied at around 250 g/da 10 days later after previous application). In the research, some properties such as green weed weed yield, dry weed yield, raw protein ratio, plant height (cm) and leaf ratio  have been investigated. According to research results, plant height values of the genotypes ranged from 232.3 to 269.7 cm for sugargrazeII and from 215.7 to 244.3 cm for greengo; green   yield ranged from 4730,5 to 5622,4 kg/da for sugargrazeII and from 4245,2 to 7033,4 kg/da for greengo, dry   yields ranged from 2138,4 to 2908,1 kg/da for  sugargrazeII and from  2424,5 to 3850,1 kg/da for greengo; raw protein ratios ranged from  12.1 to 9.1% for sugargrazeI and from 10.7  to 13.1% for greengo; leaves ratios ranged from 16.4 to 18.1% and from  20.1 to 22.7% for greengo. According to these results under Sanlıurfa climate and soil conditions, for silage and fodder production as second crop it is suggested that sugargraze II type be grown at 4. Megamineral and greengo type be grown at 5. Megamineral application. And it is also suggested that megamineral be evaluated as many types and the studies be performed.