Hello, I'm vinicius from Brazil, I have some maple trees. Right now it is spring here and they are starting to grow but my red maple (Acer rubrum) and trident maple (Acer buergerianum) have been had some issues in some new leaves. Does anyone have any idea if this can be caused by Mites or fungal diseases or something else? Thanks
@Vinícius prado good evening Vinicius and welcome to the maples forum. Looking at you photos I believe your trees are suffering from a problem called Anthracnose, this is a fungal disease that can attack during wet conditions in Spring. Spraying with a copper based fungacide is the best option, plus good plant health care. When the weather warms and is dryer the problem will recede, but leaves that are affected should be removed and destroyed. Do not allow any to lay on the soil as this can cause the return. Do not compost them either. I cannot see any evidence of Aphids or Mites. Hope this points you in the right direction.
Good idea, if it were me I would remove the infected leaves and destroy now. As it is only a few it will not cause any detriment to your maple. Another application of the copper based fungacide early next Spring should sort the problem out. Good luck and please update the forum on your progress.
@Acerholic today some leaves of red maple were like this :/ I removed them, and applied copper three days ago
@Vinícius prado good afternoon, to me that does look like Anthracnose, so the spraying will do the job. Destroy any leaves that appear infected and the second flush should all be fine. This spraying is a preventative not a cure for already infected leaves etc.
I've read some articles about it and most of them say that applying mancozeb fungicide is also a good treatment, what do you think about it?
@Vinícius prado I would stick to what you are using Vinicius, as it is tried and tested. Regarding mancozeb, have a look at this article. I think it will put you off using it. I have never used it so cannot comment. https://academic.oup.com/toxsci/article/120/2/439/1670226
