New Zealand Journal of Crop and Horticultural Science abstracts
Pruning strategies for restructuring top-dominant
central leader `Granny Smith' apple trees
I . J. WARRINGTON
The Horticulture and Food Research
Institute of New Zealand
Batchelar Research Centre
Private Bag 11 030
Palmerston North, New Zealand
C. J. STANLEY
J. F. JULIAN
The Horticulture and Food Research
Institute of New Zealand
Riwaka Research Centre
R D 3, Motueka, New Zealand
D. S. TUSTIN
P. M. HIRST
W. CASHMORE
The Horticulture and Food Research
Institute of New Zealand
Hawkes Bay Research Centre
Private Bag 1401
Havelock North, New Zealand
Abstract Eighteen-year-old, top-dominant central leader trees
of `Granny Smith' apple (
Malus domestica Borkh.) were restructured
during the 1987 and 1988 dormant seasons into either palmette central leader
(initially) or pyramid central leader forms. In the palmette form, pruning was
restricted to the total removal of the uppermost east- and west-facing fruiting
scaffolds in 1987, and the shortening of all middle scaffolds and the upper
north-facing scaffold in 1988. In the pyramid form, major scaffold limbs were
subjectively removed or shortened to re-establish the desired pyramid shape
over the two dormant seasons. Both forms were also renewal pruned annually to
totally remove pendant fruiting laterals and spur-bearing wood over 4 years
old. In addition, unmodified top-dominant trees that were either renewal pruned
or containment pruned (primarily heading cuts) were maintained for comparison
with the restructuring treatments. The restructuring treatments resulted in
improved light penetration to the lower and inner canopy regions, improved spur
quality, and in a greater proportion (50% cf. 30%) of the fruit being borne in
the lower half of the tree. Cumulative yield over the 3 years of study was not
reduced in the restructured trees in comparison with the containment-pruned
top-dominant trees and was reduced by only 20% in comparison with the
renewal-pruned top-dominant trees. Mean fruit size in both the upper and lower
tree regions was not altered by the restructuring treatments. Renewal pruning
alone compared with containment pruning resulted in a total yield gain of 28%
and an 8% increase of mean fruit size in the lower canopy but did not lead to a
redistribution of fruit within the tree. Major upper canopy restructuring
combined with annual renewal pruning, therefore, achieved the greatest gains in
both yield, and fruit size along with improved fruit distribution within the
tree.
Keywords fruit yield; fruit size; light transmission;
Malus domestica; spur quality
New Zealand Journal of Crop and Horticultural Science, 1995, Vol. 23:
315-322
0114-0671/95/2303-0315 $2.50/0 (c) The Royal Society of New Zealand
1995
PDF file of entire paper: medium quality (645K); (scanned from paper original: notes about this process)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
