Apogee has been a very consistent PGR when the first application has been properly timed and where a sufficient dosage has been applied during the year. The basic strategies needed for an effective growth control program have been developed. Since the inherent vigor of a block is impacted by many factors the exact application strategy necessary for effective growth control will need to be developed by the orchard manager. Shown below is some typical data from the 1997 experiment. Trees with an ideal level of vigor may be more productive than trees that are excessively vigorous.
Gibberellic acid is produced in the terminals of shoots and acts to increase cell elongation.
By decreasing the level of GA in the plant it will inhibit the shoots ability to elongate thereby resulting in shorter shoots. Since there is some residual GA in the plant it usually takes about 2 weeks for shoot extension growth to slow. Therefore careful monitoring is essential to time this application. It is suggested that you plan on making the application when the shoots are 1 inch long. Interval Between Sprays Research has shown that the interval between sprays can range from 10 to 14 days depending on the vigor present and on the dosage of Apogee that had been previously applied.