The effect of C-2-carboxyphenyl derivatives of certain heterocyclic compounds on root geotropism in cress seedlings

The effects on root geotropism of 2-carboxyphenyl derivatives of various five- and six-membered heterocyclic compounds have been assessed. In an assay involving cress seedlings, appropriately substituted derivatives of isoxazole, 1,3,4- and 1,2,4- oxadiazoles, 1,3,4-thiadiazole, 1,2,4-triazole, thiazoie, pyridine, pyrimidine and pyridazine were highly effective in eliminating the geotropic response.