- Author: Craig E. Kallsen
Some instances of significant scorch of the leaf canopy in Golden Hills orchards have come to my attention in the past two weeks. We do not understand the causes of scorch, and the most prominent cultivar demonstrating symptoms over the years has been the male cultivar Peters.
Scorch is not a disease but appears to develop, abiotically, later in the season, under hot temperatures. In my breeding work, there appears to be a strong genetic component in whether a given set of progeny will develop leaf scorch and associated early leaf defoliation.
I have also observed that with respect to Peters and other breeding selections in our trials that scorch appears more readily in some years than in others. Water stress later in...