Blackberries dying off

This is actually a follow up on another post but this is specifically a blackberry issue so I started another thread. I had some issues early spring where some of the BB’s leaves were yellowing, after awhile the veins stayed green and the yellow got yellower (if thats a word). Now this is not all of the blackberries in the row just a few canes ( Mainly Triple Crown) well now they are dying but the new growth and the lower portions of the affected canes still look fine. any suggestions?

Just a wild guess. Check for cane borers/knots at lower leaf nodes.

Kind of looks like Raspberry Root Rot, which I have had a small outbreak of in the last 2 years on my Caroline plants, I just rip out the cane and roots in one shot. It is slightly depressing to overwinter these canes only to have them die during the spring. I plan to switch to more SWD friendly summer bearing cultivars that fruit earlier. I will be on the look out for root rot resistant varieties in the spring next year and will raise the planting area a few inches with TONS of compost, which can be helpful in preventing future outbreaks or so I’ve read…

In the winter, water/snow sit in the lower raspberry area.

Root Rot