This study was aimed to provide seed germination and seedling growth of sorghum x sudangrass (Sorghum bicolor (L.) Moench) hybrids at low temperature by using gamma radiation and magnetic field strength. Seeds of two hybrids ("Aneto" and "Sugar Graze") were treated with different gamma doses (0-control, 100 Gy) and magnetic field strengths (0-control and 75 mT) for 72 hours while some were applied with both gamma radiation + magnetic field. Germination trials were carried out for 10 days in an incubator at 15°C temperature. Germinated seeds fromeach treatment were transferred to pots (5 pots with 4 seeds each) and cultured for 28 days in growth chamber at 15°C temperature. In this study, germination percentage, seedling growth percentage, seedling height, root length, seedling fresh and dry weights, and water content of seedling were determined. Lowest results in all parameters in both hybrids were observed in the control treatment without gamma radiation and magnetic field strength application. The highest values in all parameters studied were recorded in seeds treated both by gammaradiation+magnetic field strength applied together in "Aneto", and in seeds treated with magnetic field strength in "Sugar Graze". As a result of the research, gamma radiation and magnetic field strength applied to seed increased seed germination and seedling growth at a low temperature of 15°C
