ARS | Publication request: APPLE AND PEACH TREE RESPONSE TO SCORING AND RESTRICTION OF TRUNKS

Submitted to: Annual Cumberland Shenandoah Fruit Workers Conference
Publication Type: Proceedings
Publication Acceptance Date: November 25, 2000
Publication Date: N/A

Technical Abstract: Management of tree size and excess vegetative growth is a significant expense to orchardists. Scoring tree trunks can inhibit shoot growth but results have varied among species and even among cultivars of apple. This variation could be associated with imprecision of scoring that is inherent in cutting a tree with a saw blade or knife. Restricting trunk diameter enlargement with a band tightened to a specified tension may allow more control and improve control of vegetative growth. The objectives of this experiment were to determine effects of trunk scoring and trunk restriction on growth, photosynthesis, and leaf carbohydrate levels in apple and peach trees. Apple and peach trees were planted together near Kearneysville, WV in April 1997. In May 2000, 4 treatments were installed 20 cm above the graft union: (1) the trunk was cut to the secondary xylem with a hacksaw blade (score); (2) the trunk was completely encircled by a clamp with a 2- cm band width tightened to 10 inch pounds (band); (3) the trunk was firmly encircled with waterproof tape (tape); and (4) untreated control. By June scoring inhibited shoot elongation nearly 50% in apple and 38% in peach. Scoring continued to inhibit shoot growth throughout the growing season in apple but scoring did not inhibit peach shoot elongation after June. Band and tape treatments did not inhibit shoot elongation. Trunk diameter was not suppressed by any treatment but a trend of reduced diameter growth was apparent in banded trees. Photosynthesis was reduced during August in banded trees and soluble sugars were 16% higher in banded than control apple trees. Although banding did not affect vegetative growth the year of trunk restriction, reduced photosynthesis and diameter growth caused by banding may affect growth and fruiting in subsequent years.