GO-MR-2-PRUNINGby Sanne Kure-Jensen
“Forks belong on your dinner table, not in your orchard.” Jon Clements, UMass Extension Educator shared his witty rules for pruning fruit trees, especially apples and peaches. Clements led a hands-on pruning demonstration at Sweet Berry Farm in Middletown, RI.
For a Central Leader style orchard, “select trees with 4 to 5 branches or ‘feathers’ fairly high up the tree,” said Clements. For hi-density plantings on dwarf rootstocks, a sturdy system with four wires will support the trees during their productive years. The Tall Spindle style orchard uses trees planted 3′ apart with 10′ to 12′ between rows. To secure braches to wires, use u-hooks like those from OESCO (www.oesco.com). Using rubber bands or wires, tie young branches aiming slightly down so they do not get too vigorous.
Clements reminded apple growers that apple trees fruit on 2-year old and older wood. He likes to prune apple trees after Jan. 1 to ensure complete dormancy. Clements said, “Growers don’t have to be fussy about sanitizing tools in the winter. If the orchard has a history of Fire Blight, be sure to sanitize tools between cuts when pruning during the growing season.” He recommended starting with your largest trees. Clements made these recommendations for pruning apple trees using the Central Leader style:
1. Remove one or two of the biggest branches using a bevel cut, especially large branches near the top of the tree. Seek a balance – no one branch should be much larger than others .
2. Use diameter- based or ‘2-1 rule’ pruning to remove branches close to or larger than the diameter of the trunk.
3. Avoid heading cuts – like the plague.
4. Singularize branches – remove Y- shaped branches or forks. Cut back the branch aiming down. Cut back near a major branch, leaving one viable bud for renewal branches.
5. Remove Water Sprouts – branches growing straight up from a random spot on a branch without fruiting wood.
6. Remove vertical wood. Remove pendant wood – branches that aim down. (Cut back 1/3 to 1/2).
7. Maintain leader. NEVER use a strong heading cut to control height.
Other general pruning suggestions include:
1. Spur pruning – remove one-third to one-half of the lowest fruiting wood or spurs, especially those aiming down. This helps biennial fruiting trees like Honeycrisp produce a consistent annual harvest.
2. Maintain a tree height of 90 percent of row width.
3. Remove any weak wood or dead branches close to a healthy joint.
4. On all pruning cuts, maintain the Branch Collar to allow proper healing.
5. Remove no more than a quarter of total branches in any given year.
6. Remove crossed or rubbing branches.
7. Maintain space and air between trees in the rows and adequate space between rows for equipment like mowers and sprayers.
Peaches fruit on new wood. Using clean tools, start pruning peach trees during dry spells when trees are blooming. Pruning at temperatures above 50 degrees F will decrease chances of Perennial Canker and speed healing. The later you finish pruning, the smaller the fruit will be as energy went into growing those shoots. Minimize secondary wood and hat racks caused by heading cuts. The results of renewal cuts are unpredictable in peach trees.
“Shade is the enemy for peaches and leads to weak wood,” said Clements. Reduce shade at the top to keep the lower wood strong. Remove all dead wood as it can carry Brown Rot.
Peach diseases limit most northeast growers to 10-15 years from a peach tree. “Once your orchard has Brown Rot, you will always have Brown Rot,” agreed Sandy Barden of Barden Family Orchard, in North Scituate, RI.
“Peaches grow like a weed” said Clements. His guidelines include:
1. Select 4 – 5 main Scaffold branches 2′ or less high. Remove other major branches
2. Simplify branches – remove Y branches. Cut back near a major branch, leaving one viable bud for renewal branches.
3. Remove small, weak, upright wood and pendant shoots  – branches that aim down.
4. Leave 30-75 pencil-thick fruiting shoots per tree
“Do most of your thinning by pruning,” advised Clements.
Fruit pruning helps increase fruit size. Open tree styles allow for machine pruning in winter of spring. Follow-up by hand thinning after fruit set. To reduce the overall vigor and size of trees, close planting makes the most difference. Dr. Jim Schupp, Associate Professor of Pomology at Penn State University removes weak and overly vigorous shoots leaving pencil-thick shoots or fruit sticks with three fruit buds each. Aim for 600 to 620 bushels/acre. If you leave too many fruit in the trees, the trees will yield smaller fruit.
Dr. Schupp described peach training styles: Perpendicular-V has 5′ spacing between trees and Quad-V has 7′ spacing. Hex V has 10′ spacing between trees. Schupp’s research showed the most productive system per acre has been Quad, closely followed by Hex-V. The least productive style is Open Center, at least for the first three years.
Dr. Schupp recommended these varieties: ‘Sweeten Up’ with strong production starting in year 3. ‘Loring’ started more slowly but produced more in subsequent years. The amount of bearing surface (fruit sticks) determines the yield. Peach yields increase with irrigation during the final swell.