Normally when I see black on apple twigs I immediately think fire blight but am not sure on these twigs. It almost looks like a fine black soot on the last six inches (tip end) of 2016 growth.
No other signs of blight: no shepherd’s crook, no wilted leaves, no visible cankers, no leaves or stems remaining attached during winter.
It did occur on varieties not known for blight resistance like Nickajack and Junaluska.
Need your opinions please. The paper behind the twigs is bright white.
I kinda doubt it. That sooty look seems like a mildew to me, and I’m trying to remember where I’ve seen it. And those are nice, stout twigs, whereas I expect FB on brand-new stuff- the current years growth. (They are from the 2016 growing season aren’t they? I can’t even get to my apple and pear trees yet without wading through knee-deep snow.)
I’m not very familiar with mildew except the kind that looks gray- I get it on my lilacs and sometimes on Williams Pride apple that seems prone to it. It feels like early Christmas if this is just a mildew of some kind!!!
I know sooty blotch affects the fruit, don’t know if it turns twigs black-ish.
That stuff appears on very active shoot tips from the previous summer, in mid-winter. I think it has something to do with lots of green fuzz forming on those active growths, and then the fuzz dies back in winter and turns to black fuzz. I don’t think its a problem.
Hambone, I’m really glad you asked that question, I have that black stuff in several of my trees and was convinced it was fireblight. About a month ago I yanked out my Blacktwig apple tree that was pretty covered in the stuff thinking it was FB, oh well, more room for another tree.