Effects of Gibberellin and Alar Sprays upon Fruit Set, Seed Development, and Flowering of ‘Bartlett’ Pear1

Abstract

Abstract Spray applications of gibberellic acid (GA3) were tested for their effects in increasing fruit set when applied during bloom in two commercial pear orchards in which cross-pollination was limited. No beneficial effects were obtained, and flower bud formation was inhibited at concentrations of 20 to 100 ppm. In one year, the inhibitory effect of GA3 upon flowering was partially offset by spraying with 500 or 1000 ppm of succinic acid, 2,2-dimethylhydrazide (Alar) at petal fall.