I recently went on a farm visit to a grower that had some plants showing symptoms of dead or damaged stem tips on Premier cultivar blueberries. Once arriving, it was apparent that it was uniform across this particular field. The damaged stem tips were only at the higher positions of the plant. The stems on the lower portions of the plant appeared healthy. 

We broke off some of the damaged tips to analyze the tissue damage. We found that the dead part of the inner tissue of the stem, the pith, had turned brown. This is a tell-tale sign of cold damage. This damage would have occurred the previous fall and the injury showed up when the plants started leafing out. It would have been during a time where we were experiencing moderate temperatures and then had a cold snap while the stems of the plant were still actively growing.  

After finding this injury, the recommendations would be to stay timely with disease management practices and spray timing since the affected areas of the plants could be points of entry for disease. Also,  mowing or pruning the affected stems would prevent issues later on.  Mowing earlier after harvest will also allow time for the new growth to grow out and harden off for dormancy before cold temperatures are more likely.