Blueberry tip die back
I did not receive the photo when I opened the message the first time. Based upon your picture there are a few options.
Based solely on the photograph, I cannot determine the exact cause of the dieback. The following are two diseases that call for the similar cultural controls (non-chemical controls). The PNW Disease Management Handbook does not list any chemical controls that are for home owners for either of these diseases. I have included links to the PNW Disease Management Handbook for you:
Twig Bligh - Cultural control
· Purchase healthy planting material and/or do not use plants with injured branches.
· Prune out, remove, and destroy infected and dead branches.
· Avoid wounding or injuring plants.
· Encourage plants to harden off in winter to avoid frost damage.
· Use plant spacing and canopy management that promotes good air circulation.
Bacterial Canker - Cultural control
· Plant resistant cultivars.
· Prune out all diseased wood as soon as it is noticed and especially before fall rains.
· Avoid late-summer nitrogen fertilizer applications, which can lead to winter injury.
· Prune susceptible cultivars during dry weather if possible.
Another option may be Blueberry Scorch Virus, although I think that it is one of the diseases above. Here is a link to the PNW Disease Management Handbook: http://pnwhandbooks.org/plantdisease/blueberry-vaccinium-corymbosum-scorch
If this is a plant problem that is causing economic losses, you may choose to send a sample to the Oregon State University Plant Pathology Department and they can do more to determine the exact cause; however there is a charge for this service. We can facilitate shipping a sample from the Tillamook County OSU Extension Service office at 2204 Fourth Street in Tillamook.