By Kathryn Taylor
University of Georgia
What can you do in five minutes with one tree, a piece of plastic
and a pair of pliers? For one thing, you can get bigger, sweeter
peaches.
|
Research conducted at the University of Georgia has shown that
girdling peaches with plastic cable ties effectively increases
the size and total sugars in the fruits without hurting the tree.
The traditional girdling method involves removing a thin strip of
bark from around the trunk or scaffold of a fruit tree. This
keeps the sugars made by the leaves in the upper part of the tree
where the fruit is.
A better way
The problem with this method is the formation of wounds that
insects can infest or diseases infect.
Using cable ties to girdle the tree, though, doesn’t cause any
injury. Besides making this year’s peaches bigger and sweeter,
cable-tie girdling advances the maturity and possibly improves
the quality of fruiting wood for next year’s crop.
Refining the best method for this practice is still a work in
progress. UGA researchers are continuing their work to learn as
much they can about the technique’s effectiveness.
For example, the method relies on having enough time after
placing the cable tie for the tree’s girth to grow enough for the
cable tie to constrict the sugar movement down the tree’s axis.
It appears that it doesn’t work as well for early-maturing
cultivars as later ones.
How it works
Cable ties are placed on the trunk or scaffold branches 4 to 6
inches below or above the crotch. A rolling motion with pliers is
used to completely tighten the ties.
The first research used two 3/16th-inch plastic cable ties per
scaffold or trunk. But subsequent tests have switched to a single
1/3- to 1/2-inch cable tie. Black ties appear to hold up better
than white ties.
You have to remove the ties at or just after harvest so the tree
can recover.
Studies have been done only with applying ties to fully dormant
trees during the winter. Studies are under way to see if applying
ties in the fall, before the leaves fall, will make it more
effective on early varieties.
In Georgia, the method works best on irrigated trees and
varieties that ripen in early June or later. It works best, too,
on tree trunks that aren’t damaged or otherwise misshapened,
which keeps the tie from making tight contact around the whole
tree.
(Kathy Taylor is a horticulturist with the University of
Georgia College of Agricultural and Environmental Sciences.)
