With warm sunshine overhead, today was a good day to cut some pecan trees down (photo at right). We removed six more trees from our Kanza block according to our pre-determined
tree thinning plan.
The trees in this block are growing at an incredible rate. Just look at the cross section of one of the trees we cut down today. Over the past 4 growing seasons, the annual growth rings of this tree averaged more than 1/2 inch per year (photo at left). However, not all trees in this block are growing at the same rate. Generally speaking, the trees on north end of this planting are growing faster than the trees farther south. This variation in tree growth rate is largely due to a gradual change in soil conditions.
Every winter I walk through the planting to measure trunk diameter and look up at tree canopies to see if they are starting to get too close.
Looking up is the best way I know of determining when to thin out trees.
Here's a series of maps that tells the story of our the thinning efforts over the past three years. In looking at these maps, each green circle represents a tree and the relative diameter of each tree is depicted by the size of the circle. The red lines cut through all the trees that will be removed once the entire field is thinned. I placed a black circle over the trees that are to be removed during each particular thinning year. As you look at the maps, you'll note that the trees slated for removal one year disappear off the map of the next year's tree removal plan.
Thinning an orchard over several years has many advantages over thinning the entire block at one time.
1. Trees are removed in time to prevent sections of the block from becoming overcrowded.
2. The number of trees removed per year is minimized allowing yield for the entire block to remain at a high level.
3. The work of thinning a block of trees is spread out over several years.
When established in 1995, there were 144 seedling trees planted in this block. These trees were then grafted to Kanza during 1998-2000. Starting at tree age 17, we began our planned tree thinning operation. We removed 7 trees in 2012, 5 in 2013, and 6 in 2014. At this point, we have removed only one-quarter of the trees that will eventually be cut to complete the thinning plan. I'm sure more trees will need thinning a year from now.
