On Earth, living organisms interact with each other and form ecological systems. Such interactions have long been known and studied on a global scale. Allelopathy is a phenomenon observed in many plants that release chemicals into the near environment either from their aerial or underground parts in the form of root exudation, leaching by dews and rains, and volatilization or decaying plant tissue (Rice 1984). The released chemical compounds into the environment act on other organisms, such as weeds, plants, animals and microorganisms, by inhibitory or excitatory ways. These chemicals ac-cumulate and persist for a considerable time, thereby imparting significant interference on the growth and development of neighboring weeds and plants