Hello everyone, I have a branch on a Mikawa yatsubusa that is showing signs of dark, the rest of the tree is normal, so I suspect something wrong. It's a tree I'm really attached to, because it took me some years to grow and start looking a bit decent and also because it's one of the most beautiful and stunning cultivar. I saw those black parts after the tree had been fully covered by snow and I thought it was just some dirt. But after a week of rain, they are still there. I replanted it last fall together with 4 other maples that show no sign of disease. I used soil from the compost area behind the vegetable garden. It is planted near a spot where there was a big Buxus that I removed. I don't want to move it because it took me some work to get that area looks good and the tree is very nice where it is. In the case it is verticillium, would it be possible to just remove the soil and replace it with a good one? Also, I'd like to keep the branch if possible as it is a part of the harmony that the tree provides. But if I have to cut it to save the tree I will do it. Here are some pictures, maybe someone could tell me if it is some sort of disease, or give me an advice? Thanks
Good evening, IMO your Mikawa Yatsabusa has all the signs of Pseudomonas syringae, now this cannot be cured, but removing the infected stems and burning and also using a copper based fungacide will help control this. The well known Bordeaux mix is used effectively on the pruned ends by many. Did you prune in the Autumn? This can allow pathogens to take hold. Wet weather is also often a good breeding ground for this. I never prune until late Winter early Spring to stop this happening. Regarding the soil I would consider a bottom drench of whatever copper based fungacide you use. Hope this is of help.
Good morning Acerholic, First, thank you for taking the time to reply. I have never pruned this tree since i have it, but i had to remove all my maples last year in the end of July because I was moving to another house and I had not the choice to wait for autumn. He was sadly poted in the first plastic pot i found and stayed like that till October before beeing replanted so the maple has been definitely stressed. It's been raining a lot (and still) after a lot of snow. Anyway, thank you for pointing out the Pseudomonas syringae and for the advices. I will cut the branche and try to find a fungicide in the next weeks. I will also replace all the soil with a mix of perlite,peat and pouzzolane. I will also check the roots and eventually do some light pruning on them. I hope that will allow the tree to survive and keep growing. I also hope that the other maples in the area will not be infected. I'll post updates of the results in the next months.
Not a problem at all, I hope I have identified the problem for you. With what you have said you are going to do now IMO sounds perfect. Your beautiful Mikawa was indeed suffering from stress hence it being susceptible to attack. Carry out the procedures and I'm certain in a couple of months time your trees will be on the road to recovery. Do update the forum on it's progress, with photos please, as I'm sure everyone will enjoy seeing your trees.
Sorry Acerhotic, i don’t completely agree your diagnosis, signs of Pseudonomas syringae. All brown spots are localised near divisions in branches, it looks bee due from a special appearance of the rings witch separate each branch from an other. Of course, by a so rainy weather, Shin-Deshojo must use a copper fungicide to prevent any infection during this winter. And don’t prune any branch, i don’t think it is necessary. When you transplant a tree once time, it is not a good plan to transplant it again some month after. A third would bee a big risk.
Hello Pierre, That is my thought, but as is always the case, others will have different opinions that I fully accept.
Hi opusoculi, Thank you for input and advices, it's always good to have differents opinions. I will spray a fungicide asap, for the rest i am a little confused as i like the fact that I should not have to cut that branche if i listen to you. But at the same time I still think there's something wrong because the other branches of the tree do not have any brown tips. I understand that the black around each node could be a minor thing, maybe natural. But in the fourth picture (bad one sorry), the brown is extending all long the branche and I can see the difference with all the other branches of the whole tree (they remain green and clean, even at the nodes). So I have to make a choice: -keep that branche that I like so much and time will tell if you were right. -or cut it and get rid of the risk that it could extend to the whole tree and maybe die. About a third replanting, I understand it's a risk, but I still think it would benefit the maple to get a new aerated and clean soil to eliminate a possible root or soil problem as long as I do not disturb the roots too much and plant it in the same place (we are almost at the right moment of the year to replant a maple before they wake up). So I will take the risk. I still don't know what is the best option for that branche... Anyway I'll keep this post updated and I thank again both of you for your time dedicated to my problem.
Whatever you do, please don't drench the ground that the roots sit in with copper. First of all it's a pollutant and should be used with case, but mostly, it is a bactericide and fungicide, and will kill beneficial fungus in in soil (mycorrhizae) that your maple needs to thrive. IMO!
I agree completely with Emery. Don’t make this mistake that would destroy the good bacteria in your soil. Pseudonomas does not affect the roots at all. @Shin-Deshojo . You have moved your tree twice, the roots are disturbed, your tree is not longer feed normally. Maples that lose racines select one or more branches that they no longer feed. At the beginning of this process one observes abnormal brown diffuse colorations that are not true diseases (diffuse is a sign). My opinion about this branch you suspect of disease will evolve into gray or perhaps slowly recover in spring and the year after. If it dies you will say it was pseudonomas; without calling into question the weakness of the roots. If it survives you will see that he did not have it; when a tree is affected by pseudonomas, the brown symptoms do not disappear in the spring; a cooper spray can stop the évolution, but brown spots don’t disappear. If they slowly disappear in spring and next, that would prove it was not Pseudonomas but insuffisant roots . So disturbing your tree again will do more harm than good. @Acerholic . Concerning diagnosis and our different opinions about, i take a stand because that tree is a case that will allow to refine other subsequent diagnosis.
Hi Emery, Thank you for your contribution. I will follow your recommendations by not using copper on the roots. @opusoculi Your detailled explanations about the roots convinced me and as I also practice a little bit bonsai with Japanese maples, I remember now that I observed more than one time the relation between roots cutted or damaged and the lost of a branche. So you may be right on this one. I will apply the fungicide without cutting the branche and see what happens during the season. And about removing the tree from the soil a third time, I am really tempted to do it as I am not confident with the compost soil i used and would feel better renewing that soil with a more aerated and adapted one. But again, your knowledges speak by themself and I will stick with what you recommend. @Acerholic I don't know which of you as reason, and I guess time will tell and it will be a good lesson for me and also for futur similar problems on this forum. I also want to say that I am a long time reader of this forum and I can tell that you are always welcoming new members and trying to help anyone that has a problem. You give a lot of life to this forum with your enthusiasm and kindness. It is clear that your are truly attached to the world of maples and I hope my thread did not bring any animosity between members. This community is awesome and definitely a true gift for the internet and maples lovers. I hope I did not type too many grammatical errors as I am not native english speaker.
Thankyou so much for your very kind words, I hope I can give help to anybody who asks for it on this forum.Members don't always agree with remedies and procedures and often have different experiences with treatments, but it is always friendly disagreements. That is what this forum is all about, finding the best answer to a problem with lots of input. I hope all goes well with your tree.
I remember a discussion about hydrogen peroxide. Here, you get it in pharmacies with the label "Stabilisée à 10 volumes". I used it (roughly a table spoon for 75 cl, about one and a half pint) on a couple of small trees that had symptoms of fungal diseases, and they recovered - rule of the thumb : heard about it from people who grow plants indoors, hydroponics like tomatoes in rockwool, or plants that make you think you're a genius whereas you're not... ;0)
I found the link again : Hydrogen peroxide As it doesn't stay in the soil and isn't harmful for the insects, maybe it's something that should be experimented.
