My young Zestar apple tree has developed many brown leaves
This Zestar tree was acquired from a local nursery in April or May of 2016. It was then planted in my mostly sunny frontyard. Many blossoms from the beginning and had a good winter. Again, during spring 2017 there were many blossoms, plus I had several apples start to develop. In general a very healthy looking 6-1/2 foot tree. I have not pruned anything yet. I did recently add some loose ties to the slender branches to prevent any potential apples from bending them beyond their strength. About early to mid June 2017, the leaves on the 2 lowest branches began to turn brown. This has progressed to the point where one of the lowest branches is over 80% brown leaf, and it appears to be a goner. This at first only appeared to be affecting the 2 lowest branches, but now is seeming to move throughout the tree. Also, the small fruit that remains has pinhead sized marks (pest?) that may not be related at all to the brown leaves. Note: There was some Scot's weed/feed applied to the surrounding yard about a week before I noticed the leaf browning. Can my Zestar tree be salvaged?
It's difficult to make a certain diagnosis based on photos, but what we can see suggests that the tree may be severely affected by fire blight. If fire blight is present, the prognosis would not be dire if only a branch or two were damaged. However, the damage shown in the photos appears to be scattered throughout the tree. Was the tree hit by hail this summer? Wounds caused by hail make apple trees particularly susceptible to this disease.
We don't see evidence of herbicide damage.
Compare the twigs and leaves of your tree with this example:
Reading this bulletin may also help you determine whether fire blight is present.
Thanks for the information. It is possible that we had some hail during the time before I noticed the leaves. I can't find any evidence of the canker or ooze that is mentioned in the articles which you directed me. But the rest of the symptoms sure seem to be spot on.