Hey guys, my japanese white pine has been healthy in the last years but approximately 3 weeks ago started to develop yellow needles on one single branch…!
Overwatering, underwatering, fungus, insects, when was it wired?
From the picture it looks like there is some more needles turning yellow at the base of the bundle.
Also let me correct you, This tree has 2 needles per bundle, where a Japanese White Pine has 5 needles per bundle. Looks like a Japanese Black Pine.
Thoughts anyone 
Most pines will drop old needles in the autumn, but this looks like a dead branch. Up to you to look for clues. Not JWP
All above plus think when was the last time you re-potted it. It might be part of the root ball lacking oxygen…? Seems like anything underground to me.
How’s your percolation? Probably a root issue since it’s not all the needles. The Sheen (the part directly under the trunk) isn’t getting enough water and oxygen. If you don’t want to repott it now, scrape the surface off, rinse off the loose dirt while holding it at an angle so it washes off. Then put a tape barrier a couple inches high all the way around and add some substrate to the top. Within a few weeks you should see a difference.
Any time I have root problem now, that’s the first step.
Ryan has a good video on this with precise directions. Can’t loose with this method.
Looks like a dead branch to me. Could be a dozen reasons for that. I think your biggest problem is that’s not a Japanese White Pine. If you’ve been caring for that tree as if it were, I’d start there with why you could be losing branches.
Thx buddy! Great and very constructive advice 
Sorry to all: JBP !!!
