Irradiation (1, 2 or 3 hours) of elite wheat grains by THz radiation (3,68 THz) induces a shortening of seed imbibition period. The most pronounced effect was observed after two hours of irradiation. Irradiation of 3rd class seeds does not influence seed imbibition period. It is assumed that shortening of imbibition period caused by THz radiation influence on conformation of m-RNA and proteins of endosperm cells that regulate a water movement into grains. THz radiation induces an increase of stem and panicle length, panicle mass, grain number in panicle and grain protein content. These changes can be conditioned by influence of THz radiation on seed genetic system.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.