Juniper White Needles

My young junipers has some white signs at some branches.

You guys an idea what next?

Thank you!

It looks like residue from a spray that was applied before the new growth came out. Does this sound like it might be an option?

So this is not powdery mildew or something what I need to clean out?

I don’t see an indications that the tree needs treatment. It would be help to see the overall look of the foliage, but since the white is only on the old needles, it looks like residue from a past treatment.