Plant Growth Regulator Use in Apples

Author(s): Teryl R. Roper

Plant growth regulators (PGRs) can be used with some precision for thinning fruit, regulating growth and adjusting harvest periods for apples. These products are absorbed by plant cells, primarily through the leaves and fruit, where they interact with the bio-chemical “machinery” of the plant. They work by mimicking naturally occurring plant hormones or by blocking the production of natural plant hormones.

This publication provides information on which plant growth regulators to use for a specific effect and gives instructions on how, when, where, and in what quantities to apply them.

University of Wisconsin-Extension