Please help identify a "persistant" leaf problem: mineral, roots, fungus?

Would someone help me identify some problems on some new growth and old growth? the problem is mostly my maples, but I seem to have it on a cherry and a pear, and a fringe tree, too. Not all of my maples have "it". My soil mix is approx 80% sifted turface, 10% turkey grit, and 10% sifted pine bark fines. I defoliated a Trident forest and approx 5% of the new leaves have dark brown drying blotches and some of the leaves are curling. I water at least once per day, in the morning; and at dusk when I get home from work if they look dry. I wonder if I am watering too much. My soil mix is very free-draining. I have sprayed neem oil three times (approx two weeks apart) during the past 2 months. Here are the pics:

First is Acer rubrum (Red Maple, first year's leaves)


Trident Maple, new growth


Acer ginnala (Amur Maple)


Prunus (weeping cherry)


Sweetgum (Liquidamber)


Pyrus (pear)


Another Trident Maple


Thank you for any help or advice! Salut, Todd

The Acer rubrum has a common leaf spot/rust. It doesn't seem to be anything other than unsightly on any of mine, but I've found no way to prevent it. I just remove and destroy the leaves.

Most of the other leaf issues (except the sweetgum) look to me to be leaf dessication/burn -- because of the very, very hot days we've had here in the SE. My flowering quince and a couple of tridents have had it off and on this spring/early summer. Again, just remove the leaves; perhaps a bit more shade on the POTS (I have very little shade available where my trees are).

Liquidambar have few health issues. It could also be leaf burn, but it could also be the result of some other physical damage to the leaf.

Anyway, except for the minor probem with the red maple, I don't THINK any of these are disease related.

JimLewis wrote:The Acer rubrum has a common leaf spot/rust. It doesn't seem to be anything other than unsightly on any of mine, but I've found no way to prevent it. I just remove and destroy the leaves.

Most of the other leaf issues (except the sweetgum) look to me to be leaf dessication/burn -- because of the very, very hot days we've had here in the SE. My flowering quince and a couple of tridents have had it off and on this spring/early summer. Again, just remove the leaves; perhaps a bit more shade on the POTS (I have very little shade available where my trees are).

Liquidambar have few health issues. It could also be leaf burn, but it could also be the result of some other physical damage to the leaf.

Anyway, except for the minor probem with the red maple, I don't THINK any of these are disease related.

Thank you, Jim! I feel better and will keep tabs on them. I have to rethink my bench placement to allow for more shade for the sun "intolerants". i appreciate your time and reply. Salut, Todd

I am wondering if Maples particularly may be intolerant of Neem oil. Some other treatments cause distortion and browning of their leaves.

Maples (tridents especially) react badly to soap sprays. I've never used Neem, but if it IS an oil spray, the oil, plus the heat, could easily cause a problem. My only issue with that might be that I don't see that every leaf is involved. The oil heating up should cook every leaf that it touches. That's why you generally don't use oil sprays in summer -- even those whch claim to be OK in the heat. There's heat and then there's heat -- and we've been having the second kind here in the southeast for a couple of weeks now. It was 96 (F) here yesterday while I was mowing the pasture!!!!!!

Hi Todd.
I'm sorry to say I believe this is a fungus. It looks exactly like the problem I had here in Australia last season including the species. When I showed pictures of thios to Matt Ouwinga he recognised it as a fungus that he had seen on occasions before affecting Tridents but it is interesting none the less to see pictures of a disease the same as my trees have here in Australia!.
I had seen this fungus for a number of years but only learnt more about it since it hit bad with the right conditions last season.
Here is all I have learnt about it.
http://www.ausbonsai.com/forum/viewtopic.php?f=19&t=3927&p=44120&hilit

For either fungus or sunburn, I have found Dyna Gro ProTeKt to be very helpful. It is available at large nurseries. It is Potassium silicate & helps strengthen cell walls. If you can get Potassium silicate from a chemical supply company, it is said to be cheaper.
Iris

bonsaisr wrote:For either fungus or sunburn, I have found Dyna Gro ProTeKt to be very helpful. It is available at large nurseries. It is Potassium silicate & helps strengthen cell walls. If you can get Potassium silicate from a chemical supply company, it is said to be cheaper.
Iris

Thank you, Iris.

Thanks everyone for your suggestions! I really appreciate your help!

Wow I just logged on looking for clues to exactly this problem, and I'm not far from you Todd, in Maryland. My acers are the only trees suffering but they have it considerably worse than yours. New growth is especially susceptible on palmatums, but on the trident old growth is slowly dying back as well. All the new shoots are burning out on both types. It has been going on for over a month now, and the new growth the trident is trying to push now is tiny, and somewhat curled under, when it is still green at least.

I've been thinking fungus and alternating spraying with a neem oil and (I think) sulfur based solution. Honestly neither have seemed to help. It has been hot but the trees are in dappled shade, have not been allowed to dry out, and the landscape maples have not suffered from this.

Velodog2 wrote:Wow I just logged on looking for clues to exactly this problem, and I'm not far from you Todd, in Maryland. My acers are the only trees suffering but they have it considerably worse than yours. New growth is especially susceptible on palmatums, but on the trident old growth is slowly dying back as well. All the new shoots are burning out on both types. It has been going on for over a month now, and the new growth the trident is trying to push now is tiny, and somewhat curled under, when it is still green at least.

I've been thinking fungus and alternating spraying with a neem oil and (I think) sulfur based solution. Honestly neither have seemed to help. It has been hot but the trees are in dappled shade, have not been allowed to dry out, and the landscape maples have not suffered from this.

Hi Velodog2,
I'm inclined to think it is the heat. My landscape "everything" (including Jap. maples) are doing well. Also, I don't see any of these symptoms on the wild flora. I have two tridents which seem fine. I moved the maples to a more shady spot and hope this will help. My new growth on some of the trees are just as you described: tiny and curled under...and I was thinking "... at last the leaves are reducing... not in the way I intended..." Are you a member of PBA? Salut, Todd

Well I don't really believe that the problem is the heat, but I really don't know what it is which is why I'm here. I actually had it toward the middle of last August for the first time and if I remember right that was right about the start of a cool wet period. It essentially defoliated some of my palmatums by september, and that wasn't a great time of year to be doing that. Some of them struggled a little to come back this spring.

Not a member of any clubs except this one.

Hey Kevin, My red maple FREAKED out on neem oil treatment it seems. I used it lightly as a foliar spray once a week earlier in the spring and when it dawn on me that Neem may be the cause of the lack of vigour and funny looking leaves, i stop the neem treatment. the bugs got bad, but the growth exploded and is LUSH green at this time.

Hey Guys did you read the thread I linked. This is almost definatly the same thing I have been going through. The small leaves is another big telltale. Two trees can be sitting next to each other and one is affected and the other not. It can cause little trouble and go away as the growth picks up or it can stall the tree seriously to the point of death if given the right senario. Do not defoliate the more leaves you have on the tree the better the tree needs constant energy from it's leaves to fight the fungus otherwise the fungus will take the upper hand. Bravo fungucide has been the only thing that helps.
Here is that link agian
http://www.ausbonsai.com/forum/viewtopic.php?f=19&t=3927&p=43946&hilit=fungus+trident#p43946

This continues to come and go. The trident seems to be making some progress toward recovery. However new shoots on all maples are still quite prone to burning out. One palmatum is losing significant foliage, with some of the mature leaves turning fall colors. I don't think it will make it. Given that I don't know what it is I have not been treating them with anything.

Searches on the web make me think again that it is a systemic fungal problem. The closest description I can find of some of the symptoms is for verticillium wilt, although that doesn't seem to be an exact match. As I mentioned, the first time I noticed the issue was during a very damp cool period toward the end of last summer. This is pretty serious stuff, for my few poor maples anyway. I am going to be looking for new hard-core fungicides I think.

It appears Daconil fungicide also contains the active ingredient chlorothalonil mentioned above in Bravo fungicide. An unsavory chemical to be sure, but what else to do? The Wikipedia description of Leaf Curl Fungus as mentioned in Bretts link does not really seem to match my disease symptoms either, as there is no whitish bloom on the leaves at any point in the progression.

I'd wager that it is not a leaf fungus. If it is Verticillum wilt, there is no treatment.

Heat will do amazing things to Japanese maples. It is NOT the heat on the leaves that is the problem. It is heat in and on the pot. Ceramic pots are heat sinks, and if the pot is a darker color they're even worse. Get your trees in the shade. If that's impossible, wrap pots in foil or white material of some sort. This is why plants in the ground are not as badly affected.

With the upper 90s temps we've been having here, some unglazed brown pots are almost too warm to carry comfortably if they've been sitting in the sun.

Water does not cool them down. In fact, water once it is warmed by the sun retains heat for a very long time.

I don't really think it is a leaf fungus either, but rather a systemic one, like verticillium. Again, the weather has been hot, but not so much more than other periods. My maples are in the shade. I brought my more affected palmatums inside the cooler house during the wave of heat last week. They continue to decline. My first encounter was last August when it was cool and damp. I don't know, just saying. Hope to know someday. Keep hoping someone will positively ID it.

Velodog2 wrote:It appears Daconil fungicide also contains the active ingredient chlorothalonil mentioned above in Bravo fungicide. An unsavory chemical to be sure, but what else to do? The Wikipedia description of Leaf Curl Fungus as mentioned in Bretts link does not really seem to match my disease symptoms either, as there is no whitish bloom on the leaves at any point in the progression.

I don't think I added any link for Wiki. Leaf Curl Fungus is simply a name I have given it as I don't know what it actually is but I gave several similar fungus. There is a possibility it is a new fungus as well. I know a pathology test was done and it was identified as a fungus but the name of the fungus was never passed on.
I can only guess you have not registered to see the pictures as you would see what I had looks the same as the pictures shown here. The only thing that could make me more sure that we are dealing with the same thing is a pathology test.
The wetness would be an encouragement for the fungus. Depending on what value you put on the trees affected I would treat with chlorothalonil considering it is a nasty chemical. The long term plan at the moment for me is removing all garden debri from the entire garden over winter good treatment of lime sulfur and probably a dose of Bravo as they leaf out just to make sure they get a good start for this year at least.

Doing a search on Daconil it is made by the same company that makes the bravo. Although the active ingredient is exactly the same it is registered as a different resistant group and states different fungal use. Have no idea how much difference it makes. Might be worth calling the manufacturer to get some advice on what the difference actually is?
http://www.syngenta.com.au/Start.aspx?PageID=10101&ProductID=786125&menuId=
http://www.syngenta.com.au/Start.aspx?PageID=10101&ProductID=47752&menuId=2053

Jim there has been many suggestions such as yours put to people with this. It makes no sense as collections that have been trained in the same place for years with no trouble are now desiccated by this. I have trees growing in full sun that are fine. Also as stated one tree right next to another with this shows no ill affect.
As stated in the linked thread. Applications of the bravo that where recommended in the results of the pathology test showed undeniable results in correcting the issue. Whether it is a leaf fungus or systemic fungus I would say the later but I kinda thought they where all Systemic. Something I am sure to learn in the future. The bravo is meant to work by suppressing spores so not sure how that fits in with leaf or systemic fungus?

In my experience, there is no fungicide available to the general public that will reliably "cure" a tree with a fungal problem, whether roots, leaves, or otherwise. They're all much better as a preventative. I neither trust nor know much about systemics.

But I've e-mailed Dr. Nina . . .

JimLewis wrote:But I've e-mailed Dr. Nina . . .

Thanks Jim. I was kinda hoping she was watching this thread.

JimLewis wrote:In my experience, there is no fungicide available to the general public that will reliably "cure" a tree with a fungal problem, whether roots, leaves, or otherwise. They're all much better as a preventative. I neither trust nor know much about systemics.

But I've e-mailed Dr. Nina . . .

This fungucide like most others I know of is stated as a preventative measure.

GENERAL INSTRUCTIONS
BRAVO is a protectant fungicide only. BRAVO must be applied before diseases occur/become established to be
highly effective. Use disease warning services or past history to determine timing of first spray. If diseases are
already present, then an eradicant product should be used first and mixed with BRAVO.

I had already seen this work for someone else with the issue so I tried it anyway and you can see from my link that it worked very well some how? I can only guess that as a protectant it prevented the fungus spores from getting to the new growth as it emerged.
I would be intrested to know what an eradicant for fungucide is. An Aussie nurseryman swears by Phosphorous acid or Yates Anti Rot here. The best thing about it is that it is as harmless as a bottle of coke.

Hi guys! Dr. Nina here (for people who don't know me because I'm been so quiet lately, I'm a plant pathologist with the USDA studying tree diseases). I'm based in Maryland, and I can tell you that this heat is injurious to maples. However, the symptoms that the original poster photographed (nice photographs, incidentally) did not especially look like heat damage. Also, the wide range of plants affected did not sound like a fungus. It could be *several* fungi, and if we had been having wet weather, I could see it simply being a "fungus-y" summer; however, it's been very dry. So I'm thinking about abiotic factors. One of the later posters mentioned alternating neem oil and a sulfur spray, and it's a bad idea to alternate oils and sulfur- it can lead to phytotoxicity. It is also a bad idea to spray sulfur in weather over 80 F, and that's what we've been having for weeks now in Maryland. It's also a bad idea to spray certain oils in hot weather, and oils can be phytotoxic to delicate plants (such as maple) no matter what the temperature. The symptoms in the photo are consistent with chemical injury and completely inconsistent with Verticillium.

The trouble with hitting "reply" is that I can now no longer see the original poster's post, so I'm going to hit "send" and then check to see if oil sprays were being used. However, for everyone else out there: you should be very cautious about using ANY kind of spray in hot weather.

I just looked, and yes, the original poster is spraying neem oil. Now, not to be harsh and judgmental, but unless there's a reason to be spraying neem oil, original poster, why are you spraying neem oil? I'm a great believer in only using pesticides when there's a known pest and you know the pesticide will be effective.

Thank you for the advice Nina! However I assure you that I was not spraying anything until the symptoms were quite evident. The last picture posted is most like my acers, with the growth tips looking like a blow torch was put to them - totally blackened. I have now noticed something maybe similar, at least like the op's other photos, on other species, but I would hesitate to conclude it was the same thing. I am however starting to see definitely the same thing on some landscape palmatums now, although less severe. I have gotten hold of some Daconil and am using it judiciously (I hope). The trident is definitely growing through it ok for now, although this started before the Daconil treatment. Another round of growth is beginning on the palmatums and I'm hoping to be able to get them established with some leaves hardened off before and if it hits again (it seems to go in waves, allowing a period of growth and then bam, total dessication with the softer new growth being more quickly affected).

If you are interested in this much Nina I could probably show you a specimen - I'm sure you are not far from me.