Friday, April 1, 2011

Target Canker on Pecan

    The tree, pictured at right, stands in a native pecan grove just  down the road from the Pecan Experiment Field. I've always marveled at the numerous cankers that cover this tree's trunk. So, with the sun finally popping out this afternoon,  I thought it a good time to take some photos.
    The canker disease pictured here is commonly called target canker., The target-like concentric rings of callus tissue form as the tree responds to the attacking fungus. The disease is caused by the fungus, Nectria galligena, which seems to infect trees at the site of branch stubs. A large number of cankers weakens the health of a tree and can lead to poor growth and low nut yield. If this tree was in my native grove, it would have been cut down years ago.
    This tree must have read my mind about getting out the chainsaw.  I think it put on this monstrous face just  to frighten me away. (click photo at left to release the monster)