Friday, November 8, 2019

Hard freeze will allow full pecan shuck opening

    I woke up this morning and checked my thermometer. At dawn, it was 22 F (-5.5 C), cold enough to freeze both leaf and shuck tissues. By mid-morning I could see pecan leaflets dropping from my trees.  The photo at right shows a Gardner pecan tree still holding on to most of its leaves. However, the leaves have the dull green cast of freeze killed tissue.

    As I stood watching, green leaves were falling off the tree. After several camera shots, I was able to capture a flurry of leaves as they blew off the tree (photo above). Note the litter of green leaves on the ground, while a strong south wind sent several leaflets airborne.

    The hard freeze also impacted the pecan shucks. The photos above show a Kanza nut cluster before and after the 22 F freeze. A few days ago, Kanza shucks appeared to be drying very slowly. Although the shucks had split, the nut was still closely held by the 4 sections of the hull. This morning the shucks looked only slightly different. The outside surface of the shucks appeared wrinkled and the hulls were beginning to pull away from the nut. The freezing temperatures caused the cells of the shuck tissue to rupture allowing water to escape and the hull to start drying more rapidly. In a few days, a lot more of my Kanza pecans will look like the cluster pictured at right.