I have a sango kaku about 6 ft tall, noticed some black diebacks at the tip of the new branches so I pruned them off... But there is another blackened spot further down closer to the main branch, not sure If i need to be concerned about it? thanks
Good morning @ronragus and welcome to the maples forum. Re your Sango Kaku, I'm afraid it does not look good. (that branch only). I looked closer and I believe there is a dark streak appearing from further down on that branch, plus some damage. The damage may well have weakened it. Any black on a maple trunk or branch is often a sign of Verticulum, but 'not' always. IMO I would remove that branch and look for any black streaking in the cross cuts. If it does have this, then Verticulum is confirmed. There is no cure for Verticulum, but trees can live with it if strong enough. Stress to a tree can often bring Verticulum to the surface. So a good care and watering regime is important.
I'm not sure this is verticilium (I hope it isn't!). The black spot is just behind a wound where a branch was pruned or ripped of. I think some rot went though the tissues, and probably a little down. So I would get rid of that branch to be on the safe side, pruning it a bit further down. The same for the "black tips". And of course, "apply some copper-based fungicide"... ^^ As you can see, I'm a bit more optimistic than "Acerholic", but all in all, he gave you good advice. ;-)
Sorry my dear, i disagree . Your sentence can conveys misconceptions. -A primary Verticillium attack is not characterized by black spots on woods. Black spots are never a symptomatic of Verticillium. -Secondary: after a Verticillium attack, several weeks or month later, during wood degradation black spots may occur; it’s because the cambium dies, ('après-coup’ we said in french). (Sometimes other secondary disease symptoms may appears and overlap.) @ronragus. Your ’sango kaku’ is only affected by a bacteriosis.
Very well put @opusoculi. I don't think I made myself too clear. I was not referring to spots, but the turning black of a maple trunk that points to Verticillium and as I said it's not 100% but a fairly good sign of this. Thanks for posting
