Q.
I have a 6-8 yr. old ash that has this white powdery looking substance on the
newer growth. Can you tell me what it is and how to eliminate it.
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| Picture from reader of white growth on ash |
A. I have seen this kind of "growth" on several vegetables and herbs as
well including peppers and basil over the years. I have sent pictures of these
two a good friend of mine, a well-known horticulturist in Arizona asking
him what he thought they were. I could tell he was giving me his best guess as
well but I don't think he was very sure himself.
Here is a post on something
similar I made back in 2012
Although
not exactly the same thing it appears to be more insect related than disease or
physiological in nature. I wish I could give you a better response than just to
keep your eye on it and let me know if things get worse. If things do get
worse, then I would direct you towards a soil applied systemic insecticide for
the tree if it is needed. That is the best I can do for you at this point.
Perhaps some are other readers might hazard a guess?
I have seen those too in Phoenix every year either now or when I am dormant pruning. I have used a 16X hand lens and rubbed them looking for goo or some darned reaction. I too have no idea but also believe they are insect eggs or insects of some kind. I doubt they harm anything. I thought they might be wooly aphids, some sort of scale or eggs. I just cannot tell enough to rule out anything.
ReplyDeleteI'm sorry, I just sent you an email about this, not realizing there was a comments section.
ReplyDeleteAnyway, I always thought this was powdery mildew, no?