Saturday, January 14, 2012

Making the Decision to Thin Trees

    Thinning an orchard is usually the toughest job any pecan grower under takes (photo at right). The hard part is not running the chainsaw, but having to watch trees, that you spent years growing, fall to the ground.  At first, a recently thinned orchard looks sparse. But, within a few years the remaining trees grow rapidly to fill the space. A year or two after thinning, you will start wondering how in the world you ever mowed around so many trees (before you thinned).

     Determining when to thin an orchard is often difficult. However, the job is made easier by looking up into the canopies of the trees. To illustrate this point, I've take three photos looking up into the tree canopies of our Kanza block. In the top photo, you can see that branches of adjacent trees have started to touch. Trees in this area of the orchard will be thinned this winter.
     In this second photo the limbs are getting close but we can probably wait another year before thinning. This brings up a point. Portions of our Kanza orchard started to crowd long before other areas. Differences in tree growth rate across the orchard were a result of differences in soil conditions (better internal drainage=faster tree growth). I drew up a thinning plan for the entire orchard but we'll remove trees only in areas where the limbs are touching.
    Ideally the limbs of adjacent trees should be about 10 feet apart. In this third photo, adjacent trees are well spaced and will not need thinning for several years.