Friday, February 21, 2014

Pecan bark peeling?

'Hark' pecan bark
   I was collecting wood from our scionwood orchard and noticed the unique bark appearance of the Hark pecan cultivar (photo at right). Young trees (roughly 6" in diameter) of this cultivar have very distinctive exfoliating bark. The peeling bark on this tree does not represent some dreaded disease but is simply the natural way this tree's bark reacts to diameter growth. The long strips of curled-up bark reminds me of the bark of a shagbark hickory.
    Bark appearance is controlled both genetically and by the growth rate of the tree. A fast growth rate serves only to exaggerate any form of bark exfoliation. If you look carefully at the bark of different pecan cultivars, you will soon notice distinct patterns of appearance. Let me show you a few examples.

'Major' pecan bark
    Major trees produce a scaly bark that seems flake off in small square patches (photo at left). This distinctive 'Major' bark pattern makes field identification of this cultivar easy at anytime of the year.

'Hirschi' pecan bark

    The bark of Hirschi also appears to crack in square patches (photo at right) but it does not take on the scaly appearance found with Major trees . This bark pattern is not terribly unique among pecan cultivars so it is difficult to identify Hirschi by bark appearance alone.

'Giles' pecan bark 

   Giles trees have a more furrowed bark appearance (Photo at right). The look is mostly non-descript and gives no clue as to the cultivar.  The bark simply looks like bark should look.
     There are many cultivar characteristics that can be used to identify a pecan cultivar. Bark appearance is cultivar specific but only some pecan cultivars produce bark so distinctive that it sets them apart from other cultivars.