[Negative geotropic effect and phytotoxicity of N-quinolinphthalamic acids and allied substances]

N-Quinolinphthalamic acids and allied substances have been prepared and studied for negative geotropic effect and phytotoxic activity. The substances (Tables I leads to III) prepared by fusion of the required anhydride and amine were tested to evaluate the negative geotropic effect on germinating roots of Lens esculenta Moench s.1. and phytotoxicity in both pre- and post-emergence tests against five representative weed species at a dose of 6 kg/ha. It was found that substances (I), (VII), (VIII) and (IX) showed negative geotropic effect of the same order of magnitude as that of the reference substance (alpha-naphthylphthalamic acid). Substances (VII), (VIII) and (IX) proved highly active in the phytotoxicity tests. The simultaneous appearance of geotropic and pre-emergence phytotoxic activity seems to be connected with the presence of an 8-quinoline residue on the amide nitrogen.