Technical Abstract: In a field study, interference by an indigenous population of corn spurry reduced the shoot weights of English pea and collard by 93 and 72 percent, respectively. In a greenhouse experiment where physical light competition by corn spurry was prevented, broccoli shoot weights were reduced by corn spurry, but pea weights were not different from the controls. Corn spurry shoot homogenates incorporated into a greenhouse potting medium reduced th growth of both species, and a concentration effect was observed. Corn spurry shoot and root tissues were sequentially extracted with hexane, ethyl acetate, methanol, and 50% aqueous methanol, and the extracts were tested for inhibitory activity using millet seed germination and broccoli seedling growth bioassays. Methanol and aqueous methanol extracts were inhibitory to broccoli; whereas, all extracts inhibited millet germination. Although both shoot and root extracts were inhibitory, shoots appeared to have a higher concentration of inhibitors than roots.