Agriculture Reference
In-Depth Information
large branches, leave branch stubs about 6 inches long. This practice helps
limit the incidence of bacterial canker in the stubs and protects the main
trunk from infection. It is especially important to use stub pruning in humid
regions, where bacterial canker is a serious problem. Also use heading cuts
to keep branches from intruding into the alleys or crowding adjacent trees.
If you are growing the trees on Gisela 5, Gisela 6, or other highly productive
rootstock, use the pruning practices described on pages 447-449.
Training Tart Cherry Trees
Tart cherry trees are naturally smaller than sweet cherry trees and are
trained somewhat differently. Tart cherry trees bear their fruit mostly on
1-year-old wood and on spurs that are concentrated on 2- to 3-year-old
wood. Due to these characteristics, the fruiting wood needs to be renewed re-
latively frequently compared with sweet cherries.
Because the fruit is generally used for processing, rather than sold fresh
in markets, growers often use mechanical harvesting techniques to reduce
labor costs. Many common training systems are designed around mechanical
harvesting, in which machines grasp the trunks and shake the trees. Re-
searchers are testing designs that use smaller trees trained to bushes and
harvested with over-the-row blueberry harvesters. They generally do not use
dwarfing rootstocks, and the trees are typically trained to modified central
leaders for both hand and machine harvesting.
In Michigan, which is the leading producer of tart cherries in North Amer-
ica, fruit specialists recommend spacing trees 14 to 18 feet apart in rows
that are 20 to 22 feet apart for standard-sized trees bearing amarelle-type
(yellow flesh) fruits. Amarelle cherries make up nearly all commercial tart
cherry production in North America. Morello cherries (red flesh) are sold in
niche markets and produce somewhat smaller trees that can be spaced 15
feet apart within and between rows.
'Meteor' and 'North Star' are cold-hardy genetic dwarfs that can be kept 6
to 8 feet tall and 8 to 12 feet wide. Plant these varieties 10 to 12 feet apart in
rows that are 16 to 18 feet apart. Dwarf tart cherries are ideal for home orch-
