Response of Flowers of Black Corinth and Fruit of Thompson Seedless Grapes to Applications of Plant Growth-Regulators

Abstract

1. Oil emulsions of beta-naphthoxyacetic acid, alpha-naphthaleneacetic acid, gamma-(indole-3)-n-butyric acid, beta-naphthoxypropionic acid, 2,4,5-trichlorophenoxyacetic acid, 4-chlorophenoxyacetic acid, 2,4-dichlorophenoxyacetic acid, 2-chlorophenoxyacetic acid, alpha-(2-chlorophenoxy)propionic acid, and indole-3-acetic acid were separately applied to Black Corinth grapes by dipping clusters of the flowers at the beginning of or at full bloom. The first three compounds were also applied to Black Corinth in aqueous solution, Oil emulsions of the first six compounds listed were separately applied to Thompson Seedless grapes by dipping clusters of fruit at one of three developmental stages. 2. The treatment at full bloom of flower clusters of Black Corinth with beta-naphthoxypropionic acid at 200 p.p.m. resulted within 12 days in berries and clusters larger than those of untreated controls. The maturation of these treated clusters was accelerated. Applications of 4-chlorophenoxyacetic acid at 5 p.p.m. result...