Abstract: | Phosphonic acid analogues of phenylalanine, tyrosine and 3,4-dihydroxyphenylalanine exhibited interesting plant growth regulatory properties when tested on Cucumis sativus L. Depending on the chemical structure, they slightly inhibited or strongly promoted the growth of C. sativus roots, while their influence on hypocotyls was negligible. Phosphono peptides based on these acids showed less significant plant growth regulating activity. |