Articles
TRAINING OF SLENDER SPINDLE TREES FOR INTENSIVE SWEET CHERRY ORCHARDS
The vigorous growth of cultivars and rootstocks, the acrotonial growth character of sweet cherries made the application of slender spindle training system complicated.
There are numerous experiments all over the world to produce dwarf cherry trees for intensive orchards.
One of the most promising training systems is described by G.F. Zahn, which needs well branched nursery trees for planting.
Establishment of spindle trees by Zahn’s method is realizable, but in the later years the renewal of fruiting wood on the basal part of the canopy may fail to be successful due to lack of permanent basal branches.
It seemed to be practical to combine the Zahn-spindle with permanent basal branches to obtain the well known slender spindle.
Branches must be developed on the basis of the canopy to counteract the stronger terminal growth.
The tree is headed only once, after planting, from the following year the central leader grows from the terminal bud.
The central leader developed from the terminal bud induces moderated growth in the upper parts of the tree head.
The strong upright shoots that may develop below the terminal bud are pinched to 3–4 leaves in the summer or removed entirely.
The weaker, almost horizontal shoots growing from the central leader form fruiting twigs in the following year if their terminal bud is not removed.
Double sectorial pruning is used only once or twice on the permanent basal branches because of its good branching effect.
The use of slender spindle trees is appropriate in intensive high density cherry orchards with spacing 4 m between rows and 1.5 to 2.5 m between trees with 1000–1650 tree/ha.