Effects of Gibberellic Acid on the Growth and Alkaloidal Content of Datura Stramonium L

Abstract

Gibberellic acid, at three dose levels, was injected into growing plants of Datura stramonium and the effects on plant habit, yield, and total alkaloidal content of the leaves and tops recorded. Increase in height of treated plants was due to increased internode length, especially on the treated side of the plant. Rapid growth in stem diameter caused axial splitting of the outer tissues resulting in the appearance of scar tissue. Increases in dry weights of aerial parts, observed only in plants treated over a limited period, were due to greater stem development and did not vary with the dose of gibberellic acid given. In plants treated at intervals over a long growing period, there was increased stem production but no gain in total dry weight. Yields of leaves and tops in treated plants were not significantly different from those in control groups. Significantly increased root weights were noted for a few groups of treated plants but proportion of root to total plant weight remained constant. There was a significant decrease in percentage alkaloidal content of leaves and tops in treated plants, the content being lowest in the plants which had received the highest dose of gibberellic acid.