Thinning a pecan orchard in a single year.

      When to thin is one of the most difficult decisions a grower must face during the life of a pecan orchard. Over the past several years, I've documented our gradual approach to thinning a block of Kanza trees. But last week, we completed a more typical "once-over" tree thinning operation in a 4 acre cultivar trail (photo at right).
    This cultivar trial was originally planted at a 30 by 30 foot spacing back in 1991. After 24 years of tree growth the limbs of adjacent trees were getting close to touching and very little sunshine penetrated to the orchard floor in mid-summer. In fact, several portions of the orchard were actually past due for tree thinning. 
    Before cutting a single tree, I mapped out the entire orchard recording the locations of weak trees or trees badly injured by wind or ice storms. I knew I would be cutting down 50% of the trees during this once-over thinning operation. However, with map in hand, I could choose a thinning plan that would maximize the removal of "problem" trees.

    In thinning the grove, we removed odd-numbered trees in the first row. Even-numbered trees were removed from row two. In row three, we were back to removing odd-numbered trees. We continued this pattern across the entire block of trees.
    Once all the trees were cut, I could look across the field at a 45 degrees from the tree rows and see an entire diagonal row of trees had been cut (photo at left).
    After removing felled trees from the field, the orchard looked wide open with plenty of space for the remaining trees to grow wide canopies. The remaining trees are now spaced 42.4 feet apart.