REGULATING VEGETATIVE GROWTH IN DECIDUOUS FRUIT TREES

Authors: Miller, Stephen; Tworkoski, Thomas

Submitted to: Plant Growth Regulation Society of America Quarterly
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/21/2003
Publication Date: 3/1/2003
Citation: Miller, S.S., Tworkoski, T. 2003. Regulating vegetative growth in deciduous fruit trees. Plant Growth Regulation Society of America Quarterly.Volume 31, No. 1, Pgs 8 - 46.

Interpretive Summary: Excess vegetative growth is often a significant problem in deciduous tree fruit orchards, particularly with apple and peach trees. Excess growth reduces fruit production, increases the need for labor-intensive pruning, lowers fruit quality, and increases pest problems. Numerous methods are available for regulating vegetative growth in deciduous fruit tree species. There has been no review of the literature concerning vegetative growth control in deciduous tree fruits. This paper provides a review of the various techniques available for regulating vegetative growth including genetic, environmental, and cultural techniques. A review of the methods for regulating vegetative growth would be helpful to researchers, students, extension specialists and practitioners.

Technical Abstract: Control of excess vegetative growth is essential in modern high-density deciduous tree fruit plantings. This paper reviews the literature concerning genetic, environmental, and cultural techniques that regulate vegetative growth. Emphasis is placed on apple and peach and the horticultural practices that have demonstrated growth-regulating capabilities. Examples of growth regulation in pear, cherry, and other deciduous tree fruits are provided where applicable. While pruning is the most widely used technique for controlling or eliminating unwanted shoot growth, this technique often has a negative impact on production. In apple, selection of spur mutations, the development of dwarfing rootstocks, and the use of plant growth regulators have proven very effective in controlling excess vegetative growth under most growing conditions. Cropping is a natural method of growth control, but annual cropping is not always possible. The effects of branch orientation, scoring, deficit irrigation, competition, and other factors are reviewed. Future needs in vegetative growth control are discussed. Over 300 literature citations provide the reader with a broad background in the subject of growth control in deciduous fruit trees and sources for additional reading.