[Comparative action of (±)-abscisic acid, coumarin, p-coumaric acid and some of their derivatives on the growth of the first wheat leaf].

The activities of (±)-abscisic acid and a number of compounds derived from p-coumaric acid and coumarin and their interaction with gibberellic acid in the control of the elongation of the first wheat leaf are examined. (±)-Abscisic acid strongly inhibits leaf growth in the presence as well as in the absence of gibberellic acid, but the inhibition is greater in the presence of gibberellic acid (3 μg/l already have an observable effect). Among other compounds, only ferulic acid and coumarin significantly reduce leaf elongation, and they are effective only at high concentrations (1.44 · 10(-4) M/l).