Wednesday, April 19, 2006

This week is devoted to training and pruning our peach trees. At Royal Oak Farm we have around 1100 peach trees, give or take a few. I say give or take a few because we tend to lose 3 or 4 each year to disease or age. Our oldest trees were planted around 1993-94. In northern Illinois, we are getting about 10-12 years out of our peach trees and have begun to replace those older trees. We began planting the new peach trees in the spring of 2004 with around 600 trees and have added about 400 more over the spring of 2005and 2006. Those trees are now in their 1st and 2nd leaf. We are training the newer peach trees to a modified vertical axis system. It will take approximately 7 days to prune and train the 900 trees which I began doing on April 17. Since I am working with peach trees that tend to lean towards an open center, it takes some additional training to create a central leader. In my next post, I will include some before and after photos for those of you who may be interested. Until then, happy orchard keeping!

Monday, April 17, 2006

In case you've wondered why no posts in the last week, here's why. Over the past 7 days, we have been planting approximately 900 new trees here at Royal Oak Farm Orchard. We had some peach trees to replace that did not survive from our 2005 spring planting. Out of some 400 trees, we lost around 40. Not too bad for peach trees in northern Illinois! We have an area in our North orchard on the west side that is prone to excessive moisture and we did lose several trees to phythopthera. Bacterial canker also took several trees. We included these diseases in our spray program and are also employing cultural practices to control them. I will cover the controls of these diseases in a later post.
We added 2 new varities of apples and expanded our Crispin and Honeycrisp varities. We now have a total of 24 varieties of apples at Royal Oak Farm Orchard.
In planting our new trees, we are shifting over to the new Vertical Axis Planting System. We are also using this same system with our 800 peach trees planted in 2004/2005. I am posting an article from Hoying and Robinson at Cornell University that will explain this system in detail.



The Vertical Axis Apple Planting System

Stephen A. Hoying & Dr. Terence L. Robinson
Cornell Cooperative Extension & Department of Horticultural
Sciences

The vertical axis planting system has recently generated interest in the Northeast because of its high productivity, high fruit quality and ease of management. Production can begin as early as the second leaf with the ability to produce more than 1000 bushels of fruit per acre by the 6th leaf. The fruit produced is of the highest quality with color, soluble solids, and size all because of good light exposure throughout the tree. It is easy and inexpensive to train and prune during the formative years. Our figures show early training and pruning costs are about 25% of that of the Slender Spindle at the same tree density and rootstock. At maturity, pruning is easy and inexpensive, a fraction of the cost of a semi-dwarf Central Leader orchard. Even though a trellis system is required to support the relatively tall narrow tree form, it is easy to erect and of moderate cost.


This system originated in France and is now used throughout the world. It and its variations are also known as the French Axe, Slender Pyramid, Triple Axe, or just plain Axe. We believe that many of the training and pruning principles gleaned from this system will become the important components of all orchards in the future.


The Vertical Axis System is based on three principles...


Principle One


Rapidly grow the tree to approximately 10 feet in height by the end of the third growing season.


This is accomplished by not heading the leader during the development years thereby growing the tree tall very quickly and preventing the development of strong upper tiers of scaffolds. The mature height of the system is determined by the choice of variety, rootstock, support system, and leader management. Mature height will rarely exceed 15 feet. In New York and the Northeast, one of the M.9 clones or B.9 is ideal for most varieties and gives a mature tree height of 10 - 12 feet. Weaker varieties can be grown successfully on Interstem or M.26. When more vigorous stocks are combined with vigorous varieties, trees are more difficult to manage.


It is necessary to install a support system soon after planting. The preferred support system is simple, relatively inexpensive and easy to install. Our recommended support system consists of a trellis with a single high wire at 7.5 ft. The wire is supported by in-lines posts 10 ft. long, 3/4 in. diameter) spaced approximately 50 ft. apart and driven 30 inches into the ground. Anchor assemblies at the ends of each row consist of an anchor post (4 - 5 in. diameter) driven 48 inches into the ground vertically and an angled (60º) inline post (3 - 4 in. diameter) driven 30 inches into the ground between the first and second tree. The wire is attached to the bottom of the anchor post and run over the top of the angled in-line posts and then down the row over the top of the vertical inline posts. It is attached to each post with galvanized 3/4 inch 12 gauge staples. Tension is maintained with wire tensioners in each row. Individual tree support poles (either a 10 ft. 1/2" diameter galvanized metal conduit or 10 ft. bamboo pole) are then placed by each tree and pushed into the ground 6 inches. The pole is attached to the wire and the trees are then attached to the pole with a plastic tree tie.


Careful leader management in the formative years is the key to making this a successful vertical axis tree. The leader is not headed except at planting when necessary to establish permanent scaffolds or balance the top with the root system. After this initial cut, the leader is NEVER headed. Vertical growth and early fruiting is maximized by not heading. It is important to support the rapidly growing leader by fastening it to the support stake as it grows. Rapid leader development and weak yet fruitful side branches are encouraged along the leader by stunting competitive shoots using a technique known as "Pinching". Pinching is simply the removal of the growing tip and developing leaves of all competitive shoots sprouting within 12 inches of the leader's terminal bud position at the start of the growing season. Pinching starts when competitive shoots reach 4 - 6 inches in length and is repeated as pinched shoots regrow more than 4 inches. Strongly growing varieties such as Crispin or Gala must be pinched 2 or 3 times each year during the second and third growing seasons. Weaker varieties such as Empire may only need to be pinched once each year. Since inching is only done from the ground and by hand, it can cost as little as $10 per acre per trip.


Principle Two


Use a minimum of pruning during the formative years.


Training trees to the vertical axis is based on the principle that no pruning results in greater flower bud formation and subsequent fruiting while pruning stimulates vigor and reduces flowering. Like most other systems, a minimum of four scaffolds is required. However, the more scaffolds the better. Selected scaffolds should have good crotch angles and not be more than 1/2 the diameter of the leader. Starting in the second leaf, shoots that compete with the leader are either removed or suppressed by pinching if they originate within 12 inches of the leader. The lack of heading of the leader allows rapid fruit bud formation along the leader. Vigor levels are easily managed in the tops as long as no pruning cuts are made and early and heavy cropping occur. The occasional strong competitive shoots missed during the pinching process should be completely removed during dormant pruning. Permanent bottom tier scaffold branches are spread or tied down during the second or third growing season to produce calm fruitful scaffolds appropriate for the spacing. During this formative period, it is important to spread and bend all vigorous growth rather than prune. Training rather than pruning encourages rapid filling of productive area and early fruiting. Early fruiting calms tree growth producing a balance between vegetative growth and production.


It is important that the leader be permanently tied at the top of the support stake to support the crop and maximize production. The leader is not pruned during this stage. Tree height is limited by cropping which bends and bows the leader above the support pole.


Principle Three


Renewal pruning of upper branches on mature trees will contain tree size and maintain a conic shape.


As trees mature, lower tier scaffolds are gradually thinned to 4 or 5 with proper vigor and position. Above that tier of scaffolds only smaller caliper fruiting wood is allowed to remain in the tree. When branches exceed 1 inch in diameter they are removed completely using a bevel cut. Latent or adventitious buds from this small stub sprout, producing weaker fruitful wood in its place. The leader is not pruned until fruit bends it over and weakens it. The weight of the crop above the support pole is allowed to bend and in some cases even break the leader before any pruning of the leader is done. This helps manage tree vigor in the tree top. Then the leader is pruned to an appropriate upright replacement. These fruitful branches in the upper half of the tree are only shortened by pruning if it is necessary to remove pendant portions of the branch.


By following these three principles you will be able to produce an orchard with tall narrow pillar-shaped tree with a strong dominant trunk, a permanent lower tier of scaffold branches and only weak fruiting branches arising from the trunk. The upper half of the tree will have virtually no permanent wood. In contrast to the central leader tree training system it has no permanent upper tiers of branches. These very narrow trees intercept nearly all the light available to them yet their narrow conic shape allows good light exposure even in the center of the canopy. The abundance of light ensures the production of healthy fruit buds, excellent fruit set, and near perfect fruit quality, particularly color


Simplified Training Recipe for the Vertical Axis Apple Planting System


First Leaf


At Planting...


1. Adjust graft union to 3" above soil level, tamp soil around roots.


2. Remove all scaffolds below 22" using a flush cut.


3. Trees with less than 3 feathers should be headed at 32" and all feathers removed using a bevel cut.


4. Trees with 3 or more scaffolds (10" long) should be headed 12" above the uppermost scaffold with all scaffolds headed by removing 1/3 their length.


Soon After Planting...


1. Install tree support system that will allow tree to be supported to 10 ft.


2. Attach tree to support system with a permanent tree tie above 1st tier of scaffolds leaving a 2" diameter loop to allow
for trunk growth.


1/4 - 1 inch Growth...


1. Rub off 2nd & 3rd buds below the chosen leader bud to eliminate competitors to the leader shoot.


2. Deflower tree.


2 - 4 inch Growth...


1. Attach clothespins to new side shoots to promote favorable crotch angles.


July...


1. Tie developing leader to support system with Max Tapener.


2. Remove clothespins.


Second Leaf


Dormant...


1. DO NOT HEAD THE LEADER OR PRUNE TREES.


2. If additional scaffolds are needed, score above appropriate trunk buds.


4 - 6 inch Growth...


1. Pinch lateral shoots in top 1/4 portion of last year's leader growth removing the terminal bud and 4–5 expanding leaves of the lateral shoot.


June 15...


1. Re-pinch all lateral shoots in top 1/4 of last year's growth.


2. Tie developing leader to support system with Max Tapener.


3. Remove all fruit on 1 year old wood and hand thin remaining fruits to 6" apart.


Mid July...


1. Re-pinch vigorous lateral shoots in top 1/4 of last year's growth.


2. Tie to leader support system with a permanent tree tie at 6' height and
tie developing leader to support system with Max Tapener.


3. Tie down 4 - 5 permanent lower scaffold branches to the horizontal.


4. Position other vigorous upright shoots below the horizontal.


Third Leaf


Dormant...


1. DO NOT HEAD THE LEADER.


2. Tie down vigorous, upright limbs below the horizontal overlooked during
second summer.


4 - 6 inch Growth...


1. Pinch lateral shoots in top 1/4 portion of last year's leader growth removing the terminal bud and 4 - 5 leaves of the lateral shoot.


June 15...


1. Re-pinch all lateral shoots in top 1/4 of last year's growth.


2. Tie developing leader to support system with Max Tapener.


3. Hand thin to single fruits spaced 4" apart.


Mid July...


1. Re-pinch vigorous lateral shoots in top 1/4 of last year's growth.


2. Tie leader to support system with a permanent tree tie at 8' height and tie developing leader to support system with Max Tapener.


3. Position other vigorous upright shoots below horizontal with elastics, weights, tape, or string.


August...


1. Tie up lower scaffolds not expected to support the crop. Alternatively, do not tie up but prune back scaffolds to prevent limb breakage, and preserve tree structure.


Fourth Leaf


Dormant...


1. DO NOT HEAD THE LEADER.


2. Remove limbs that are overly vigorous.


July...


1. Position vigorous upright limbs below the horizontal with elastics, weights, tape, or string.


2. Tie leader to support system with a permanent tie at the top of the pole.


August...


1. Lightly summer prune to encourage light penetration and maintain pyramidal tree shape.


Fifth & Sixth Leaf


Dormant...


1. DO NOT HEAD THE LEADER.


2. Shorten bottom tier scaffolds where needed back to side branch to facilitate movement of equipment and preserve fruit quality on lower limbs.


3. In each year, remove one of the least desirable lower tier scaffold branches until only 4 remain.


4. Shorten branches that have become pendant back to horizontal portion of the branch.


5. Remove up to one vigorous upper scaffold limb each year to begin renewal of fruiting branches.


August...


1. Summer prune as necessary to maintain pyramidal tree shape.


Seventh Through Twentieth Leaf


Dormant...


1. Shorten bottom tier scaffolds by pruning back to side branch to facilitate
equipment movement and preserve fruit quality on lower limbs.


2. Remove and renew 1 - 2 vigorous upper scaffold limbs each year preserving all weak fruiting wood and permanent lower tier scaffolds.


3. Shorten leader down to desired height by cutting to a fruitful side branch.


August...


1. Summer prune as necessary to maintain pyramidal tree shape and encourage light penetration.


Source: Hoying & Robinson