This paper described the results of effects of some allelochemical in the rhizosphere soil solution on seed germination and seedling growth of some crops and weeds. Those extracts of samples showed bioactivity were select6d for GC-MS analysis, More than 50 different chemicals were identified, Three chemicals have been studied in some details to evaluated their aLlelopathic effect on the germination, root and seeding groWth of wheat, maize, barnyard brass and sesban. It was not found up to now that published...