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Training Systems – Maximize Bearing Surface

Training Systems
General.
Goal – Maximize bearing surface per acre, and establish bearing surface in the minimum time
possible. Reach “break even” point of investment earlier.
In conventional, low density orchards, it may take 10-15 years to reach the break even point.
All orchards have:
1. Bearing portion (trees).
2. Support portion (row middles, spaces between trees within row.)
Likewise, each tree has:
Bearing portion, or fruiting “mantle”.
2. Support portion, or trunk and major scaffolds.
“Mantle” – outer 2-3 ft of the canopy, depending on foliage density; 2 ft is more realistic.
* Light penetration beyond 2 ft depth into canopy is insufficient to support fruiting
wood.
* Very few flower buds are initiated on wood receiving < 50% available light, and
virtually none on wood < 30%. Calculations (Big tree vs. little tree)
Assumptions: Tree canopy is a half sphere
Mantle depth is 2 ft.
8 ft row middle must be maintained to maneuver equipment.
Volume of sphere is 4/3 pi r
3
so half is 2/3 pi r
3
Large trec: 16 ft height, diameter, r=8 ft.
2/3 pi (8
3
- 6
3
) = 620 ft
3
per tree.
Total volume = 1072 ft
3
; 58% of volume is bearing surface.
Spacing: 16 ft (within row) x (8 + 16) = 384 ft
2
/tree;
43560 ft
2
/acre = 113 trees/acre x 620 ft
3
/tree = 70,060 ft
3
/acre
384 ft
2
/tree
Small tree: 8 ft high, wide; r = 4
2/3 pi (4
3
- 2
3
) = 117 ft
3
mantle/tree
Total, volume = 134 ft
3
; 87% of tree volume is bearing surface.
Same spacing as large tree – 117 ft
3
x [43560/(8x16)] = 39,817 ft
3
/acre
So, small tree not as efficient as large at equal spacings, but make hedgerow and
utilize gaps between trees within rows. Hedgerow: continuous bearing surface, 8 ft high, skirt at 2 ft.
width is 4 ft since 2 ft is max canopy depth; 100% of
canopy volume (excluding trunk) is capable of bearing
fruit.
Higher density possible; need only 12 ft between rows to leave 8 ft open.
# rows/acre ? (square acre = 209 ft on a side)
209/12 = 17.4 rows 209 ft long.
Mantle per row = [6' high*4' wide*209' long] = 5016 ft
3
x 17.4 rows =
87,278 ft
3
/acre.
With 5% slope on sides, 1/2 b x h = 36 x 4 = 144 in
2
= 1 ft
3
per
linear row ft
So, with sloped sides lose 1 ft
3
per linear foot of row, or 7273 ft
3
lost per acre, new mantle volume = 80,005 ft
3
/acre.
* Still greater than large trees despite only 1/2 the height.
Hedgerow: one of the most efficient systems in terms of bearing
surface/acre.
Orchard of the future?
Hedgerows with very narrow alleys between rows (3-4
ft), allows either a small tractor or a person or over-the-row harvester through.
Height cannot be more than about 1m + row width, or excessive shading will occur, and
no fruiting at bottom of hedge.
Over-the-row operations will replace traditional ground-based operations which require
large equipment between trees.
e.g., spraying, pruning, harvesting all done by same basic machine; different
attachments.
[see Italian literature for pictures, light interception models for diagrams] H. Traditional training systems – free-standing trees.
A. Open center or vase.
1. Head whips at ca. 24 inches, lower if smaller
tree desired.
2. Select 3-4 branches at ca. 120 or 90° spacing around trunk, 5-6 inches apart vertically;
remove other branches. Start with wide-angled crotches to avoid undesirable “bench cuts”
later (see Myer’s work).
3. Head scaffolds to induce branching, more severely on vigorous shoots than weaker ones
to make tree symmetrical.
4. Allow branching to form inverted, hollow cone shape to canopy; mantle is a “fruiting
doughnut”.
* Often used with peach, plum, apricot, and other trees with a natural tendency to stay relatively
small and bushy (poor apical control).
Characteristics:
Good light penetration, high fruit coloration and quality.
Yields are low if tree pruned severely (Georgia).
Variation is the within-row V-shaped tree; basically an open center tree in 2 dimensions,
only 2 scaffolds extending into row middles allowed to develop, trees spaced closely within
rows.
B. Central leader, modified leader.
1. Head whip at desired height ( <1 m), allow uppermost upright shoot to continue to grow
vertically (the leader).
2. Select 2-3 wide-angled limbs below leader as scaffolds, at least 6 inches apart vertically
and spaced equally around the trunk.
3. Select scaffolds as leader grows, with 1-3 ft between scaffolds on same side of tree
vertically (depending on final tree height), and equal spacing around trunk.
4. Mature tree should have “tiers” of scaffolds along a straight central axis.
Modified leader – Same as central leader initially; leader is removed, tied down, or cut to
horizontally growing shoot at desired tree height to reduce shading and loss of production in the
center of the tree.
- Hybrid between open center and central leader. ∗ Used for apple, pear, sweet cherry; all have a strong tendency to grow upright. Any other
system would be in opposition to tree’s natural habit.
∗ Trees will be tall as a result of this system.
C. Slender spindle or spindle bush. Like a diminutive central leader, but involves more
severe pruning. Will delay bearing unless dwarfing stock is used.
1. Head leader at desired height of skirt, allow 3 scaffolds to grow
horizontally below uppermost upright shoot; probably need limb spreaders.
2. Repeat at 16-32 inch intervals each year.
∗ System works best with a dwarfing rootstock and a spur-type scion
(apple/M.9, pear/quince).
∗ Can plant trees at high densities, reduce row width
∗ May need posts for support (if stock poorly anchored), and 1 or more
trellis wires to facilitate training limbs horizontal.
D. Meadow orchard.
Concept – fruit trees grown as annuals or biennials on perennial trunks, at very high
densities (1000 to 25,000 trees/acre).
Apple, biennial cropping:
1. Whip grows straight, growth retardant used to initiate flower buds at base.
2. Following year, basal buds produce 2-4 fruit per tree, leader extends 1-2 m tall to produce
leaves which support fruit.
3. Tree severely pruned to 1 bud above union during winter after cropping, cycle starts again.
Peach, annual cropping:
1. Tree planted, allowed to grow unchecked.
2. First summer, trees produce many shoots with flower buds; second and subsequent years, trees bear
fruit.
3. After harvest (early) trees hacked to knee-high; vigorous regrowth occurs by late summer (2 m+) on
which flower buds develop for next season’s crop. ∗ Must have long growing season (N. Fla., S. Ga., Israel).
∗ In cooler climates, biennial system is used where 1/2 tree fruits one year, alternate 1/2 tree fruits
the next.
Meadow orchard problems:
1. Cost of trees and planting is high.
Rooted cuttings and tissue culture may decrease cost of plants and allow
system to work.
2. Growth regulator may have long term ill side effects on
trees and/or environment (Alar on apple).
3. Requires long growing season for best results.
4. Cultural practices must be altered radically.
III. Training systems – trellised (supported) trees; high density hedgerows.
A. Palmette – Most common hedgerow system.
Developed in Italy after farm labor became scarce; permits more rapid pruning and
harvesting, easier for unskilled labor and women.
Types: Horizontal (most water sprouts), oblique, and delayed oblique.
∗ Basically a central leader with scaffolds in the plane of the row only; Scaffolds tied to wires to
reduce vigor and promote spurring (fruiting).
∗ Height and vigor controlled by dwarfing rootstock, and by tying central leader to top wire or
allow it to droop under weight of fruit.
B. Bandera or marchand (flag).
Trees planted at a 60° from horizontal to reduce vigor, apical dominance; lateral branches on
upper side of leader form scaffolds.
Leader usually points north so at low solar angles, sunlight penetrates within canopy. C. Tatura trellis.
Developed in Australia for peaches; obtain very high
yields there.
Trees trained along a V-shaped trellis with closely
spaced wires; no limbs in center.
∗ Expensive to install, difficult to prune.
∗ Not for United States, especially S.E. because of PTSL; can’t recover expense of trellis. Better to
do a within-row V or Y-shaped tree w/o trellis.
IV. Training systems for grapevines.
A. Head vs. Cordon training.
Head – Permanent part of vine consists of trunk and 4-5 small
stubs at top called arms.
Cordon – Permanent part of vine consists of trunk and 1-4 long,
straight shoots trained along a wire (cordons).
Spurs or canes developed at regular intervals along cordons.
Regardless of head or cordon training, same general care 1st 3 yr.
First year – plant vine in dormant season, head severely to 2-3 buds above union; allow to
grow unchecked.
Second year – Head to 2-3 buds again during winter, vine looks the same as first year, but
root system is developed. Provide a stake prior to spring growth.
During winter, dig shallow furrow next to trunk on both sides to expose surface
roots, prevent suckering; remove any suckers.
During summer, select vigorous shoot as trunk, remove others; train shoot along
stake, head shoot when it reaches 1.5 to 2 ft above desired head height, leaving a stub
for tying.
∗ At this point, vine consists of only a single, straight trunk, and head or cordon training is
selected. 1. Head formation. First 2 year’s training same as above.
3rd summer – All new shoots on lower 2/3 of trunk removed (rubbed off); allow shoots on
top 1/3 of trunk to grow out.
Following (4th) winter – select 4 canes, 2 on each side of trunk within plane of row, as
permanent arms, cutting them to spurs, retain some canes for fruiting.
4th and subsequent summers – select renewal spurs for next year’s crop, retain as many
canes (spurs) as vine can support.
2. Cordon formation. Requires more skill than head trained vines.
3rd summer – select 2 vigorous shoots, 6-10 inches below trellis wire on opposite sides of
trunk; remove others.
Tie shoots to wire at base, allowing tips to grow upright; tie more toward horizontal
as shoot lengthens, maintaining tips upright.
Following winter – Cut cordons back to 3/8 inch wood, weave around wire ca. 1.5 times
each.
4th summer – Allow shoots on upper side of cordons to grow, spaced 8-12 inches apart;
remove others.
Allow vines to carry fruit.
Tie fruiting canes to upper wire to prevent flopping over.
Subsequent summers – Canes selected in 4th summer become permanent arms; cut back to
spurs yearly.
B. Spur vs. Cane Pruning.
“Balanced pruning” – amount of buds left to produce fruiting shoots is based on pruning weight in
winter (see table 10-11 from G&H).
1. Spur – “short pruning”; leave only a stub with 2-6 buds on each renewal cane.
Short spur pruning: 2-3 buds.
Long spur pruning: 5-6 buds.
For use on:
*Cultivars with fruitful basal buds.
*Cultivars that are excessively vigorous (e.g., French-American hybrids).
*Wine cv’s where high quality juice is more important than high quantity. TABLE 10-11 BALANCED PRUNING FORMULAS FOR MATURE VINES AT
STANDARD SPACINGS
NUMBER OF BUDS
NUMBER OF BUDS
RETAINED FOR EACH MAXIMUM NUMBER OF
RETAINED FOR FIRST ADDITIONAL POUND BUDS FOR PLANTS AT
GRAPE CULTIVAR POUND OF PRUNINGS OF PRUNINGS 8-FT SPACING
Concord 30 plus 10 60
Fredonia 40 plus 10 70
Niagara, Delaware, Catawba 25 plus 10 60
Ives, Elvira, Dutchess 20 plus 10 50
French hybrids: All of these require severe sprouting and suckering” during spring and early summer for satisfactory growth, crop, and
vine maturity with the formulas suggested below.
Small-clustered varieties such as Foch and Leon
Millot, Baco noir
20 plus 10 50
Medium-clustered varieties such as Vidal blanc,
Aurore, Cascade, Chelois 20 plus 10 40
In years of above-average fruit set, these may need cluster thinning; weak vines will need flower-cluster thinning and careful suckering.
Large-clustered Varieties such as Seyval, Verdelet, 20 plus 10 40
Chancellor, Chambourcin, Villard blanc, DeChaunac
These must be supplemented with prebloom thinning to one cluster per shoot and careful
k
Viniferas
20 plus 20
Source: Adapted from Jordan et al. (1981). 2. Cane – “long pruning”; 9-16 buds retained at base of last year’s canes.
For use on:
*Cultivars with unfruitful basal buds (e.g., ‘Thompson seedless’).
*Cultivars which lack vigor or are low yielding.
V. Strawberry planting systems.
A. Annual hill system or “plasticulture

. 2 to 4 row raised beds, planted in fall, cropped following
spring, removed after harvest.
Only “mother” plants grown, cropped.
Most highly productive system, also expensive and labor intensive.
Choice of commercial strawberry producers, California, Florida, N. Carolina. 2.
Matted row system. Perennial (2-3 year).
Plants placed on beds in dormant season, flowers removed 1st year to encourage runner and
“daughter” plant formation in a “mat” along the row.
Cropped the next 1-2 years, removed when vigor declines.
“Mother” and “daughter” plants cropped.
Less productive, also less expensive and labor intensive.
More prone to disease.
For pick-your-own or backyard culture.