Tuesday, February 16, 2016

Orchard thinning yields great scionwood.

    February is a good month for thinning pecan orchards. It is also a good month for collecting pecan scionwood. So today, we took advantage of the sunny weather to collect scions from the trees we cut during a orchard thinning operation (photo at right).

   Once a tree is cut down, you can ready see why it is so hard to find good scions from nut bearing trees. On lower and mid-canopy limbs, new shoot growth is limited by nut production. The photo at left shows a typical lower-canopy branch. Last year's growth is highlighted by the yellow line and extends about 5 inches before terminating in a peduncle or the former fruit bearing stalk. Note that last year's shoot growth is lighter in color and displays large, prominent buds. However, this shoot does not make for very good scionwood. The growth is short, the buds are close together, and the stem is crooked. 
    Walking around to the top of the tree, I found really long, healthy shoots that would make great scions (photo at right). What was once 40 feet up at the very top of the tree, was now easily accessible from the ground.

   I cut dozens of one-year-old shoots that measured nearly 3 feet in length (photo at right). This is the perfect type of wood for cutting into scions. 

    Taking the 34 inch shoot pictured above, I cut the wood into pieces. In the photo at left, I've arranged the wood from the lowest portion of the stem to the terminal. In looking over these pieces of wood, notice how bud size increases and buds become closer together as you get closer to the terminal. For great scionwood, you want prominent, healthy buds, but those buds should be widely spaced to make grafting cuts easier.
    I always discard the terminal portion of the shoot when collecting scionwood. The terminal is crooked, has too many buds, and is nearly impossible to carve when grafting.
  On the other end of the shoot, the basal piece of wood has very small buds which are prone to falling off the stem (yellow arrow points to aborted bud scar). I'll save this piece of wood for grafting because the secondary buds can grow into new shoots. However, when I'm out grafting and have a pile of scions to choose from, I'll choose this type of wood only after I've run out of scions with more robust buds.