Chitosan, a linear polysaccharide, derived from the most abundant natural polymer chitin; is composed of 2- amino-2-deoxy-D-glucose and 2-acetamido-2-deoxy-D-glucose units. Chitosan is a biodegradable polysaccharide having amine groups elucidates its unique properties among biopolymers. Chitosan usually has high molecular weight polysaccharide and strong network of intermolecular or intramolecular hydrogen bonds [1]. Its structure results in poor solubility in most organic solvent and makes it chemically inert for derivatization. Degradation of chitosan is usually used, turning chitosan into one with low molecular weight which exhibits some special biological, chemical and physical properties which are different from that of the ordinary chitosan such as antibacterial activity [2] and antifungal activity [3]. Chitosan has very positive impact on plants growth; all plants
with chitosan had better developed roots and shoots in the field of agriculture [4]. However, the functions and
applications have been revealed to be dependent not only upon the chemical structure of chitosan but also its
molecular size. Radiation can provide a useful tool for degradation of different polymers. In the reaction, no other
chemical reagents are introduced and there is not a need to control the temperature, environment or additives. The
object of this research was to determine the influence of reducing the molecular weight of chitosan on the growth
enhancement in corn.