Antagonistic Action of Certain Stereo-isomers on the Plant Growth-regulating Activity of their Enantiomorphs

Abstract

IT has been recently demonstrated that the two stereoisomeric forms of certain α-aryloxypropionic acids can differ widely in their capacity to induce growth responses in plants. Thus, for example, the (+)-forms of α-(2-naphthoxy)-, α-(2 : 4-dichlorophenoxy)- and α-(2 : 4 : 5-trichlorophenoxy)-propionic acids possess high growth-regulating activity, whereas the (−)-isomers possess only negligible activity. The (±)-acids give an intermediate response in the tests employed^1,2.