Hi Tony,
That is a large Abies Koreana.
Usually a yellowing of the needles from the inside out is a sign of lack of moisture. This doesn’t necessarily mean that the ground is too dry, it could be that the moisture just isn’t being taken up by the tree. It could be root rot which will slowly effect a tree, although the use of weed killer sounds a bit ominous to me. Unfortunately there isn’t anything you can do now but wait and see if it recovers. I would advise avoiding any further use of the weed killer in that location as although it didn’t affect the tree straight away it can be a gradual thing. Some trees do recover from root related problems.
Kate
Ornamental Tree Nurseries
Replied: Monday 8th of November 2010 03:38 PM