Monday, May 25, 2020

Directive pruning young pecan trees

    In between rain showers, I have been trying to work on pruning all my young pecan trees. Right now, when I look out in the orchard, I see far too many trees that look like lolly-pops; Trees with a long strait stems topped by a profusion of leaves and branches (photo at right). Left to grow unchecked, this tree would develop a terrible crow's foot and no strong central leader. To avoid future problems with tree form, I like to practice what I've termed "Directive Pruning". By selectively pruning at this time of year, I direct the tree's energy into growing a single central leader and strong lateral branches.

     This year, the mass of branches and foliage on top of my young trees seems even denser than in previous years. Just look at the top of my tree (photo at left), there are multiple shoots growing from each node. Out of this mass of foliage I'll need to select a single shoot to become my new central leader.

    The frost injury we sustained back in April is the cause for the massive profusion of shoots near the top of the tree. In the photo at right, note that there are four shoots growing from a single node. The upper bud or primary bud was killed by the frost. This prompted the secondary and tertiary buds to break and to form shoots. Even the quaternary bud has just started to develop into a shoot. By pruning at this time of year, I can direct all the tree's energy into a single shoot to become a dominant central leader. 
    The photo at left shows the top of the tree after I have pruned it. I kept one vigorous shoot to become the central leader. Now that all the competition has been removed around this shoot, the new growth will straighten out in just a few weeks time. I also remove all lateral branches within two feet of the tip of the central leader. This will promote the dominance of the new leader. Below that point I allow the laterals to form but remove any branches that appear to be forming a narrow crotch angle.
     With just a few snips of my pruners, I've eliminated that lolly-pop tree and created a tree with a central leader (photo at right). 

     The photo above is another example of the practice of Directive Pruning. When pruning the tree, I start at the top and select a shoot to become the central leader. Next, I remove all lateral branches within 2 feet of the apex of the central leader. Moving down the tree, I prune off any new shoots that are growing straight upwards from a lateral branch.  At this point in the tree's life, I like to keep all well-formed lateral branches in place as long as they don't interfere with basic orchard maintenance. The additional leaf area provided by low limbs promotes both new shoot and trunk diameter growth. I will remove lower limbs in time, but this tree is about 2 years away from that job.