Abstract
1. Gibberellic acid applied in amounts of 30 and 60 μg. per plant to the fourth expanding leaf of tomato plants of a genetic dwarf variety and of a normal variety produced significant increases in stem elongation in both varieties. The 30-μg. treatment produced a relatively greater response in the normal variety than in the dwarf variety. The increase in plant height was mainly produced by elongation of nodes below the point of application. 2. Flowering was hastened by the increase in rate of stem growth and not by a change in position of the inflorescence. 3. A reduction in the number of leaflets per leaf and a change to entire rather than serrate leaflets occurred in all treated plants. 4. The gibberellin applications produced leaves and initiated indeterminate growth on the genetically non-leafy, determinate inflorescences. This action resembles the effect of the recessive gene, lf, and indicates an inhibitory action for the dominant gene lf+. It also indicates a possible anti-inhibitory role for gibberellin.