名媛直播

Hey guys,
First time posting here, though I've been a long time reader.I have a problem that only seems to effect my mugos.It started late last summer, and keeps on continuing no mater what.Yellowing of current and last year's needles, that eventually leads to major dieback.It's happening really fast when it starts.First I thought I broken a few needles while wiring, after about two weeks it got nasty, yellowing from the tips going down to the base of the needles.Checked the roots, seemed fine, healthy at the time, no pests that I could see, they haven't been repotted for what is now
3 yeas.Figured it has to be fungal, dosed it with copper based fungicide and let them go to dormancy.This year I started spraying every few weeks as buds started moving to keep the new needles safe.It still keeps coming back no matter what I do, still no pests, no black fungal spots that are visible.
Any Ideas are welcome.
Thanks!

Indoor or outdoor? If kept indoor, then this is the result from dry air and being inside.
If outside, this might be the result of inconsistant watering.

If you see no fungal, they why do you spray the tree with copper based fungicide?

I've started that particular pine about 8years ago, and I've been keeping bonsai for more then 13 years so I wouldn't dream of keeping a pine indoors, the only thing I keep indoors is ficus.
Living in the middle of Transylvania, so nights get chilly over here even in summer.
My initial thought was fungus since I have spruce that's affected close by, that's why I kept going with fungicide.