Monday, April 8, 2013

Warm night temperatures advance pecan bud break

Greenriver bud elongation 8 Apr 2013
    When it comes to spring-time bud development, warm overnight temperatures are needed to really kick start a pecan tree. For several days now,  we have had overnight low temps in the 50's, so today I went out into the grove to check things out. Our Greenriver trees had passed the inner scale split stage and moved into bud elongation (photo at above). It was only last week when I couldn't find any evidence of bud growth past outer scale split. Wow, things have changed fast.
Chetopa inner scale split 8 Apr 2013
    In walking through our cultivar trials, I found trees in several stages of bud development. I decided to photograph these stages so you can become familiar with the terminology used to describe spring bud growth of pecan trees.
   At this point in time, most of our native trees have entered the the outer scale split or moved into the inner scale split stage. Chetopa, a cultivar that originated as a native seedling at the Pecan Field, exemplifies many of our natives in terms of bud development (photo above).

    When looking at pecan tree bud emergence, you will soon come to realize that the terminal bud on each branch pushes opens first with all the buds below at earlier stages of bud development. A Kanza twig illustrates this normal pattern of variation perfectly (photo at right).  The terminal bud is in the bud elongation stage. The third bud down is in inner scale split, while the outer scale of fourth bud has split and fallen off but the inner scale is still intact.
Osage bud elongation 8 Apr 2013
    Osage is a cultivar that sheds pollen early (protandrous). In the photo at left, take a close look at the terminal bud. What looks like 3 buds developing from a single location is actually three different structures emerging from a single terminal bud. An elongating vegetative bud is located in the center. This bud will grow into a new shoot that will terminate in a pistillate flower cluster. The two lateral buds adjacent to the vegetative bud contain this years crop of male flowers or catkins.