Apple tree pest or virus?
I have 4 espaliered apple trees (3-4 yrs old). Recently, I noticed these marks that first looked like burn marks. Upon further inspection, I see that the bark is being eaten away and perhaps there is some type of borer pest. It is at the grafted joints. What can I do to prevent further damage and save my trees?
Multnomah County Oregon
I read about the bullseye rot and looked at additional pictures online. I am not sure if this is the issue. I am seeing evidence of what I believe to be a pest - possibly a borer as there are holes inside the cankers and sawdust left behind. This also is very new as I pruned last year and tied every branch down to wire and never noticed one injury or damage. This seems very sudden and significant. It looks like burn and then further damage.
I found this site that discussed weakening of plants due to sunburn and I believe that could be very possible. The berries I have in the same sun direction experience sunburn and I was thinking of how to protect them this next season. A couple of the pictures look very similar. This post is from a desert area, but as we are experiencing more drought and higher temps each summer, do you think this pest is a possibility? The flat head apple tree borer or the Pacific flat head borer. If so, how can I treat in these winter, rainy months?https://xtremehorticulture.blogspot.com/2015/08/identifying-their-damage-and.html?m=1
Thank you for your time.