Annual pruning of fruit trees is important in maintaining healthy trees and getting good fruit yields. The best time to get this chore done is in February or early March. The main reason for pruning is to allow for better sunlight penetration into the leaf canopy, which is important to good fruit set and development of high quality fruit. Other reasons are to remove broken, dead and diseased branches, create a stronger framework of scaffold branches to support a heavy fruit load, and to control the size of the tree to aid in picking and maintain aisle space between trees for movement of orchard equipment.
Without annual pruning, the leaves on heavily shaded branches will not receive enough light to manufacture enough sugars for normal functioning. The result will be smaller and lower quality fruit, less fruit, and the branches will eventually weaken and die. There will also be less air circulation, which increases the likelihood of foliar diseases such as brown rot and bacterial blight.
Red color development is also dependent on light, so increasing the light exposure of the fruit will increase color development. This is especially critical with red apple cultivars, since most do not color well under the warm Oklahoma conditions.
If pruning is too severe, extremely vigorous, unproductive wood is produced which complicates next year’s pruning even more. For this reason, it is better to remove some wood every year rather than pruning severely every three to four years. It is also important to start training the tree from the very start, selecting branches to become the main scaffold limbs and removing the others before they become large.
When pruning to train young trees, select branches that have a crotch angle of 45 to 60 degrees from the trunk. Narrower crotch angles cause a branch to be weakly attached and subject to splitting away from the trunk during high winds or under a heavy fruit load. A branch that does not have an adequate crotch angle can often be spread mechanically. This is usually only practical on those trees trained to a central leader, such as apple and pear. If scaffold selection is made early, at four to six inches of growth, the shoots can easily be spread to the proper angle with toothpicks or spring-type clothespins. The clothespins are clamped around the main stem just above the shoot to be spread, with the shoot coming up between the ‘handles’ of the clothespin. This is only effective during the spring of the first year planted, and will only affect the part of the branch right near the trunk. The clothespin need only be left on the tree a few months. Once a branch gets three years old, it is difficult if not impossible to spread.
Always cut back a branch to another branch or the trunk. Never leave a stub. Contrary to the former recommended practice, cuts should not be made flush with the trunk. At the base of a branch, there will be a ridge of bark called the collar. The cut should be made just outside this collar. Leaving the collar undamaged promotes healing of the pruning wound. Tree wound dressings have not been found to be necessary.
Peaches are normally trained to an open-center system. In this system, the tree has a relatively short vertical main trunk, with three to five main scaffolds arising from the trunk and distributed equally in all directions. The center of the tree is kept open by pruning, to allow light in from the top into the center of the tree. The height may vary according to the grower’s preference, but the trees may be kept to approximately eight feet tall. At this height no ladder is needed to prune or harvest.
Apples and pears require less pruning than peaches. Don’t remove more than one-third of the wood during any single year. The main job is to thin out damaged wood and suckers that tend to grow straight up parallel to the trunk. Red Delicious apples are notorious for this habit.
As mentioned earlier, the best time for pruning fruit trees is in February or early March. The longer you can hold off, the better, especially with peaches. Pruning slightly reduces the winter hardiness of the trees, so you do not want to prune in early winter while the coldest weather is still to come. It is better to prune during bloom than to prune too early. Delaying pruning also allows you to assess winter damage to the flower buds and to leave more flower buds when pruning, if necessary. Almost all of the pruning in fruit trees can be done with a pair of lopping shears, a pruning saw for the large cuts, and a pair of hand shears for fine cuts.
If you have any questions, or would like further information on this or other related management topics, visit us on the west end of the Clay Jones Community Building at 1901 S. 9th Avenue in Durant, or call (580) 924-5312.
The Oklahoma Cooperative Extension Service offers its programs to all eligible persons regardless of race, color, national origin, religion, sex, age, disability, or status as a veteran, and is an equal opportunity employer.
Bryan County Burn Ban is in effect.
February 23-25, Bryan County Junior Livestock Show, Bryan County Fairgrounds. Premium Sale will be on February 27.
March 7-8, No-Till Conference, Shawnee, OK. For more information look at the following website: http://notill.okstate.edu/2017-no-till-oklahoma-conference/No-till%20Agenda2017.pdf
April 6, 2017 – Eastern Oklahoma Beef Cattle Summit, Southeast Oklahoma Expo Center, McAlester, OK. Pre-registration required by March 30 and cost is $10. A registration form is available at the Extension Office or you can call the Pittsburg Extension Office at 918-423-4120.
Robert Bourne is a Bryan County Extension Educator.