Susan, Thanks for the question. That bark damage does not look good. That white tube should be placed on in late fall and be taken off in April. A tube on in the summer months will often cause fungal growth and decay to the bark. Not a disease per se.

Is that area of damaged bark on the south or southwest side of the trunk? If so, it could be sun scald damage. Here is a link to more info on sun scald: https://extension.umn.edu/planting-and-growing-guides/protecting-trees-and-shrubs-winter

I believe the leaf discoloration is a symptom of environmental stress; likely the damaged bark. With the tube removed, in time, the inner bark should continue to grow to cover the damaged area. No benefit to painting or treating with any tar, etc.

Paul -Tree Care Advisor volunteer

If it has been more than two years since the tree was transplanted, then remove the bag. If less than two years keep filling it. ITT should be removed before winter.

Paul 

Yes, put the tube on for the winter then remove it in April.

Paul