Under treatment condition of volatile oil from Ageratum conyzoides , the germination rate, fatty and protein enzymes, soluble protein of seed, root length, shoot height, chlorophyll content, the number of nodule of seedling and the number of branch, peg and pod as well as flowering period of peanut were tested and determined. All items and indexes demonstrated that the germination, growth and development of peanut were inhibited by volatile oil from A. conyzoides in the field. Obviously, allelopathic...