Apple growers and extension specialists in northeastern North America are seeing an alarming increase in the numbers of orchards, mostly young orchards, where trees are declining or dying due to dysfunctional trunks. The phenomenon has been named sudden apple decline (SAD) or rapid apple decline (RAD) because affected trees seem to decline very quickly. The visibly affected areas of the trunks exhibit cankers, cracks, or dead phloem and cambium, but causes and contributing factors are often difficult to determine. In some cases, multiple factors may be contributing to the tree losses.
The SAD phenomenon was discussed in a recent presentation that I made at the Empire State Expo in Syracuse, NY, that was held 17-19 January 2017. An updated version of the proceedings from that talk and of the Power Point used for the presentation ( 25.8 MB) are accessible by the indicated links.
For another perspective on this problem, see the excellent article by Dr. Kari Peter, Plant Pathologist at Penn State’s Biglerville station, that appeared in December 2016 and that can be accessed here.
On another note, I have updated my previous blog post on bitter rot with a link to the Power Point on bitter rot that I used at the Cumberland-Shenandoah Fruit Workers conference last December.
Posted 23 Jan 2017