Monday, April 9, 2018

Pecans survive cold snap

    Over the weekend, a cold front swept across the plains and dropped our temperatures down to 22 degrees F (Saturday morning 7 April 2018). At that point in time, the buds on our pecan trees were just starting to swell and the outer scales of many apical buds had fallen off. The photo at right shows a typical pecan terminal.
    The terminal bud at the very top of the shoot has lost it outer bud scale. Likewise the upper bud on the right side of the shoot. The bud immediately to the left of the terminal bud is actually the secondary bud to the terminal bud and is still covered by its outer scale. Further down the shoot on the left side, a bud has split open the outer scale but its has yet to fall off.

    To check for cold injury, I removed the terminal bud for closer inspection (Photo at left). Once the outer scale falls from the tree, you can see that the bud is actually made up of three parts. In the center is a large vegetative bud that produces a new shoot that terminates in a pistillate flower cluster. On either side of the vegetative bud are two lateral buds that will produce only catkins.

     I sliced the bud in half to reveal the health of the bud (Photo at right). Again you can see the large vegetative bud in the middle flanked by the catkin-containing lateral buds. Fortunately all the tissues inside the bud a still green and healthy. A cold injured bud would have appeared black in color, two days after the deep freeze.
   I guess its a good thing pecan trees break bud late in the spring. The freeze on Saturday, did significant damage to my peach crop (trees were in full bloom).  Which is the main reason I have 20 acres of pecan trees and only 2 acres of peaches. Peaches are great when you have them but pecans are far more reliable.