Effect of gibberellic acid on flowering of apple trees

IT has been shown by Sironval et al.1 that gibberellic acid (GA3) affects growth of the main shoots in apple trees (var. Golden Delicious) and apical dominance. Apple-trees treated with 300 p.p.m. GA 3 (1-2 ml. given twice a week on the apical bud and young leaves) throughout the growing season are greater and form twice as many lateral shoots as control trees. © 1963 Nature Publishing Group.