Gummosis

If you see gummy sap leaking out of your peach, plum, cherry or apricot tree, it is probably gummosis. When jelly-like material oozes out of the trunks of your trees, especially fruit trees, most people first think about insect attack. That may or may not be the cause. This sap leak usually occurs when the tree has a perennial or bacterial canker or is attacked by the peach tree borer. But, it can also be caused by any physical wound including winter damage, damage from gardening tools, etc. 

 

The fix is the Sick Tree Treatment but here is some more information about this common affliction.