I started seeing Pine Tip Blight in Marin County about 10 years ago (2001). It is a pathogen that effects the growing shoots on Monterey Pines, Pinus Radiata. It is usually associated with trees found in close proximity with thick foliage and in poor condition. If untreated it puts the infected tree/s on a downward spiral in regards to health and safety often leading to removal.
The best therapy for infected trees is to prune out all dead material and thin the tree's canopy by removing redundant limbs and shortening branches that remain. Thinning allows for better light and air circulation that helps dry the foliage. Shortening limbs allows the tree to use more of it's energy in producing chemical compounds to help it resist pathogens. Thinning also lessens the sail effect on trees by allowing wind to course through the canopy instead of pushing against a wall of foliage, making for a safer tree.
All Pines benefit from a balanced thinning. It strengthens the trees architecture, and increases the ratio of resources available for demand on the storage capacity of the tree's root system. Plus, it makes for a more esthetically pleasing tree.
* Monterey Pines should only be pruned during the wet season to reduce the possibility of Pine Beetle infestation.