AbstractA number of derivatives of gibberellic acid have been prepared and their growth‐promoting activities compared. Eleven salts and four acyl derivatives showed activities similar to that of gibberellic acid when applied to the roots or to the leaves of dwarf pea seedlings. Five esters and nine acyl derivatives of esters showed no activity when applied to the leaves; most of them were moderately active when applied, in aqueous culture solutions, to the roots possibly because they underwent slow hydrolysis.