On the variety of auxinic activity of indol-03-acetic, 4,5-benzoindol-03-acetic and 4,5-naphthoindol-03-acetic acids

Abstract

The increase of theí€ ring System of theí€ 3-indol acetic acid, modifies theí€ ensemble growth activity, leading to a limitation of theí€ secondary activity in theí€ 4,5-benzo-indol-3-acetic acid and to theí€ inactivity in theí€ 4,5-naphtoindol-3-acetic acid. This remarle is discused with regard to whatever is known in theí€ present about theí€ relations between ring and carboxylated chain in theí€ active growth substances.