Increased in mycotoxin has proven risky to human health and animals as a carcinogenic and mutagenic materials that occur upon exposure to them serious illnesses. But, it can be controlled by exposing these fungi and toxins to different doses of gamma or the UV ( Ultra Violet) rays. This study has explained the effectiveness of using gamma rays to prevent growth of the fungus Aspergillus flavus on cotton seed and destroy action of the toxin aflatoxin B1 at all doses of radiation used. All attempts to isolate the fungus again from the seeds has failed in all replications of gamma irradiation treatments as compared with the control treatment in which no radiation dose was used or the irradiation of the UV, which did not prevent the growth of fungus which was successfully re-isolated from all samples treated with the radiation doses of the UV rays.

Key Words :Gamma, Ultra Violet (UV), Aspergillus flavus, Aflatoxin B1