Tuesday, May 22, 2012

Pecan bark flaking off?

Kanza Bark
    The other day a pecan grower expressed his concern about the cultivar, Kanza. "It looks like Kanza is susceptible to sun scald. The bark is flaking off". Well the bark looks like it is flaking off (photo at right) but the sun has nothing to do with it. Kanza, like its Major parent, has bark that exfoliates in blocky patches.
    When trees grow in diameter the older (and outer) bark can not stretch to cover the increased girth. As a consequence the outer bark cracks. The shape and pattern of these cracks are genetically controlled and do not indicate any inherited weakness.
    There is huge variation in bark appearance among pecan trees. Growing behind my office are three seeding trees, all the same age and roughly the same diameter. All three trees are in perfect health. Bark appearance among these trees ranges from furrowed to shaggy (Photos below).