ID this pest please Murraya + Trident Maple curl

[shanemartin]

Just discovered 2 major issues in the past few days. the first is this pest which is attacking leaves on some young healthy Murrayas.

And #2 the frustrating, difficult to diagnose, much debated Trident Maple Leaf distortion and burnt edges. I've had this problem with the Tridents before but thought I'd escaped it this year, as I had been able to give my trees more attention and care than the previous couple of years. This spring, all of them leafed up without a hint of the problem, and were full of hardened healthy perfectly formed leaves. A couple of weeks ago some were pinched, and some were given a light prune. All the new growth is affected badly, so I sprayed with Confidor. Only 2 trees have eluded the problem, and are all getting the same watering, feed, and morning sun til 1.30pm. All are on the same bench, and all are affected except one which I moved away to another area just in case. I read the 6 pages on a thread about this problem from a year ago, but there didn't seem to be anything conclusive or resolved. I'm still confused??
OK>>>> I've just revisited the affected trees and I think this is not one specific problem alone, but a combination of at least 2 things.
Thrips, and wind burn..... For the past 2 weeks we have been hammered by warm northerly winds, and I have noticed 2 very different leaf shapes. One being curled, rounded, and burnt edges. The other being malformed without the burnt bits. This is the one I'm sure is Thrip affected, as in this photo it shows what looks to be thrips. This was found by unfolding some deformed leaves. On others I discovered TINY white things that moved. Here are the pics...... first the Trident samples. then the Murraya leaf. Looks like a tiny caterpillar burrowing under the top surface of the leaf......

[squizzy]

The one on the murraya is leaf miner. Generally not a major issue. Just remove the damaged leaves and put in a sealed plastic bag.

Squizz

[shanemartin]

The one on the murraya is leaf miner. Generally not a major issue. Just remove the damaged leaves and put in a sealed plastic bag.

Squizz

Thanks Squizzy.... That's a relief. I not come across it before.
cheers

[Matthew]

Shane i dont think the tridents have a pest issue. I believe it might be fungal. Have a look at several previous post by Bretts about this issue.

[Paulneill]

I had issues with tridents . First thing to do is submerge the entire root ball in Water for 20 mins to kill anything that maybe in the soil . And also spray Yates anti rot on the foliage . I did this and mine is showing signs of improvement all the damaged leaves are still there but new growth is fine .

[shanemartin]

Shane i dont think the tridents have a pest issue. I believe it might be fungal. Have a look at several previous post by Bretts about this issue.

Matthew what about the tiny white crawlies I found then? I've read everything Bretts and others have written in the 6 pages of discussion on this forum.... Nothing seems conclusive ..... well to me at least.... or am i missing something??
Back to the drawing board I spose.

[Matthew]

The little white pests maybe chewing on something but dosent account for that disorted look. My experiance with tridents in rockhampton qld where i had a condition that looks like yours. I put it down to humidity and lack of winter but who knows? i havent had this issue since i moved south as i got rid of all my tridents up there and aquired new stock. what i see looks differant to what i see in one of your pics. Im no expert on the subject but it seems some areas get this condition more than others . i dont think its a watering, fert or lack off. Sun damage is differant also. I dont think ive answered any questions hopefully they will recover. If it is a fungul problem than it may go away but return down the track.

[63pmp]

I have had similar problems with some maples this year, especially since the hot winds began a few weeks ago I found it to be a combination of things.

First thing is to check the pH of the soil, high pH 7 or greater causes iron deficiency in maples which gives yellowing of leaves and new growth, can also cause burning of edges. Low pH causes growth problems and manganese toxicity, which gives similar symptoms.

Secondly what sort of fertiliser do you use, how much and how often? This is important because maples ar sensitive to ammonium, excessive watering encourages ammonium toxicity, as well as excessive fertiliser use. NH4 toxicity causes black spots, burnt edges and tips of leaves, distortion etc. It will also cause Calcium deficiency which causes the horrible burnt and distorted leaves at the tips of shoots. These symptoms are much worse in trees that are actively growing in the sun.

If you are feedingwith ammonium products and pH is rising it can cause ammonia to form in the plants, whihch is very toxic.

Check the pH first, as it can cause all the symptoms you are experiencing.

Paul

[Bretts]

Shane i dont think the tridents have a pest issue. I believe it might be fungal. Have a look at several previous post by Bretts about this issue.

Matthew what about the tiny white crawlies I found then? I've read everything Bretts and others have written in the 6 pages of discussion on this forum.... Nothing seems conclusive ..... well to me at least.... or am i missing something??
Back to the drawing board I spose.

Pathology test stated fungus, treatment the pathology test recommended (Bravo) showed dramatic results in fixing the problem. Don't know what you expect but that is conclusive enough for me.

See here for a condensed version of what I have found on this.
viewtopic.php?f=19&t=3927&p=101954&hili ... us#p101954

I would guess the white crawlies are something different. I have some tridents with similar looking "eaten foliage" It has not worried me much as it is on stock trees and I was putting it down to thrips or something that the damage is already done.

But pics 3 and 4 look exactly like the fungus to me.

[shanemartin]

Shane i dont think the tridents have a pest issue. I believe it might be fungal. Have a look at several previous post by Bretts about this issue.

Matthew what about the tiny white crawlies I found then? I've read everything Bretts and others have written in the 6 pages of discussion on this forum.... Nothing seems conclusive ..... well to me at least.... or am i missing something??
Back to the drawing board I spose.

Pathology test stated fungus, treatment the pathology test recommended (Bravo) showed dramatic results in fixing the problem. Don't know what you expect but that is conclusive enough for me.

See here for a condensed version of what I have found on this.
viewtopic.php?f=19&t=3927&p=101954&hili ... us#p101954

I would guess the white crawlies are something different. I have some tridents with similar looking "eaten foliage" It has not worried me much as it is on stock trees and I was putting it down to thrips or something that the damage is already done.

But pics 3 and 4 look exactly like the fungus to me.

First of all Bretts let me say my reference to you was in no way meant to infer "your" findings were inconclusive, and if that's how you read it, then i apologise. What I was trying to say was.... there seemed to be so many ideas and causes and possible this and possible that.... it just seemed to go nowhere for me, and as I said in my submission, "Maybe I missed something" which I obviously did, being the "conclusive" pathology testing and recommended Bravo treatment. I will certainly give this a try tomorrow. However the leaves in pics 3 & 4 look very different from each other to my eye at least?? You sure it's the same thing?
Well I hopefully I'll to get to the bottom of this soon and will be able to post some positive results in the coming months. How do you guys know all this stuff!!!!
BTW Bretts, what are your thoughts on the Ammonium toxicity theory in the above post?
cheers mate

[shanemartin]

I have had similar problems with some maples this year, especially since the hot winds began a few weeks ago I found it to be a combination of things.

First thing is to check the pH of the soil, high pH 7 or greater causes iron deficiency in maples which gives yellowing of leaves and new growth, can also cause burning of edges. Low pH causes growth problems and manganese toxicity, which gives similar symptoms.

Secondly what sort of fertiliser do you use, how much and how often? This is important because maples ar sensitive to ammonium, excessive watering encourages ammonium toxicity, as well as excessive fertiliser use. NH4 toxicity causes black spots, burnt edges and tips of leaves, distortion etc. It will also cause Calcium deficiency which causes the horrible burnt and distorted leaves at the tips of shoots. These symptoms are much worse in trees that are actively growing in the sun.

If you are feedingwith ammonium products and pH is rising it can cause ammonia to form in the plants, whihch is very toxic.

Check the pH first, as it can cause all the symptoms you are experiencing.

Paul

Much food for thought Paul.....
I think I just read your blog on CRF's and the trident maples with the same issues........ yes???
I started the spring with a handful of chook poo per pot.... and have been giving fortnightly doses of Seasol to promote root growth, as the trees were all lifted from the ground end of winter, so this is their first season in training pots. The worst affected tree is in a 400mm nursery pot, and the others are in 120mm deep wooden training boxes. All new growth to date was vigorous and well formed. 2 weeks ago I gave them their first light prune which also coincided with us getting belted with unseasonal warm northerly winds. After reading your blog and the post above, I am getting the feeling that the ammonium and calcium issues may well be bang on the money. I have had quiet concerns about the soil consistency and make up of this commercial grade mix which I have been using for the past couple of years with pretty good results.I buy it by the trailer load... however this batch of trees are only getting a small amount of sun at the moment, as I wanted them to establish a bit longer before they were exposed to full sun. Now I'm starting to think they're staying to wet before the next watering. I have thought about adding some diatomite to the mix to open it some, which would encourage it to free drain more easily. Being that the trees have only been in these pots for 3 months, I'm worried about disturbing the new fragile roots though. Could you step me through how I should proceed which should rectify the Calcium and ammonium issues in the process ..... yes?
Please be gentle Paul, I did poorly in science and chemistry as a kid, and i'm now middle aged and loosing some marbles, but i promise to give it a good crack at understanding.....

[63pmp]

Hi Shane,

I think the first thing to recognise is that we don’t actually have confirmation that the problem is ammonium toxicity or calcium deficiency, or both. It may well be something else. It could be a fungus, who knows? That’s why we have to keep an open mind.

I think these problems are like having a persistent cough. All your friends will diagnose the disease; one will say cold, another flu, another pneumonia, someone will say cancer. You eventually go to the doctor and he’ll ask you about all the symptoms, look down your throat, feel your glands, take your temperature etc. Then he’ll say something like it’s probably a virus, but let’s get these tests done. Your friends are all jumping to conclusions, your doctor is working through a long list of what it might be and then ticking of the improbable as he examines you, the tests knock off or confirm more possibles. We need to be like the doctor.

We have a list of possibilities a few symptoms, but nothing really concrete to go on with. This is why a pH test is very important. Maples are sensitive to ammonia. If your pH has crept up to 7 or higher, than we can pretty much say it’s ammonia toxicity and a pH problem. If we are right, then adjusting the pH should give better growth. A Manutec soil pH test kit from the hardware or plant nursery is sufficient for testing the pH of your potting mixes. This either confirms or knocks off a possibility. If it’s pH related, we have to look at why it’s rising, is it your irrigation water alkalinity, or your fertilisers? Or something else?

Ammonium and plant physiology is rather complicated, and throwing in calcium makes it worse, my head hasn’t quite got around it yet. I’d like to know what the pH is before trying to guess if it’s something else.

Look forward to hearing what the pH is.

Regards

Paul

Some extra stuff I wasn't sure whether to post or not, it might be interesting for some.

Ammonium is a funny nutrient, it pretty much stops calcium from travelling up the xylem, it is absorbed along the entire length of a root, and also exchanges calcium off soil particles, so encourages leaching of calcium from your pots. Just about every commercial fertiliser DOES NOT include calcium in their mix bt they have loadsof Ureaand Ammonium, so your fertiliser may be making your mix Calcium deficient, which becomes evident in rapidly growing plants, not very much in restricted finished bonsais. At temperatures below 16 C bacteria in the soil stop converting ammonium to nitrate, but if it’s cool and wet, causing low oxygen levels in your soil then bacteria will convert nitrate to ammonium, increasing its concentration, which plants than take up. Urea is stil converted to ammonium in cool wet soils, so urea based fertilisers can be a problem as well. High ammonium in the soil prevents Calcium from being taken up, even if there is an adequate supply of calcium in the soil.

Calcium is very immobile in plants, once it is out of the xylem and into leaves it will not move from them, so if calcium is not being taken up by roots almost continuously in actively growing plants then deficiencies will form very quickly. Additionally calcium is only taken up by a very short section of root near the very tip. So anything that stops root growth, or damages the root tip stops calcium from being taken up. This includes low temperatures, low oxygen (water logging) salinity, and ammonium/ammonia toxicity.

At pH >7 ammonium will convert to ammonia. Ammonia is a non-valent dissolved gas, it easily penetrates plants cells and damages internal structures, specifically stopping nitrogen assimilation, and hence cell growth.

What can you do? Don’t feed your plants to heavily during wet weather with anything that contains nitrogen, top dress suspect plants with gypsum and water with magnesium sulphate, this will reduce Ca Mg deficiencies and assist with leaching of ammonium. Improve drainage of boggy pots, tilting them if shallow, sticking a wick up one of the holes can help. Slip potting into a deeper pot may also work, don’t damage roots or remove old soil. Be patient as warm weather is coming and things will improve. Don’t over water them when it does get warm so that the root tips can recover. Keep an eye on soil pH, testing is any sort of leaf symptom occurs.

[Mojo Moyogi]

Some pretty good advice there Paul.

Shane i dont think the tridents have a pest issue. I believe it might be fungal. Have a look at several previous post by Bretts about this issue.

Matthew what about the tiny white crawlies I found then? I've read everything Bretts and others have written in the 6 pages of discussion on this forum.... Nothing seems conclusive ..... well to me at least.... or am i missing something??
Back to the drawing board I spose.

Pathology test stated fungus, treatment the pathology test recommended (Bravo) showed dramatic results in fixing the problem. Don't know what you expect but that is conclusive enough for me.

Hi Brett, Is there any chance we could get some details from the pathology report that you had done?

MSDS for Yates Bravo here: http://msds.orica.com/pdf/shess-en-cds- ... 020761.pdf
Wikipedia info for the active ingredient: http://en.wikipedia.org/wiki/Chlorothalonil

Cheers,
Mojo

[shanemartin]

[quote="63pmp"]Hi Shane,

I think the first thing to recognise is that we don’t actually have confirmation that the problem is ammonium toxicity or calcium deficiency, or both. It may well be something else. It could be a fungus, who knows? That’s why we have to keep an open mind.

We have a list of possibilities a few symptoms, but nothing really concrete to go on with. This is why a pH test is very important. Maples are sensitive to ammonia. If your pH has crept up to 7 or higher, than we can pretty much say it’s ammonia toxicity and a pH problem. If we are right, then adjusting the pH should give better growth. A Manutec soil pH test kit from the hardware or plant nursery is sufficient for testing the pH of your potting mixes. This either confirms or knocks off a possibility. If it’s pH related, we have to look at why it’s rising, is it your irrigation water alkalinity, or your fertilisers? Or something else?

Ammonium and plant physiology is rather complicated, and throwing in calcium makes it worse, my head hasn’t quite got around it yet. I’d like to know what the pH is before trying to guess if it’s something else.

Look forward to hearing what the pH is.
Regards
Paul
Hi Paul... excuse the edit, just conserving space.
A wealth of advice for this mind of mine to digest..... I have the Manutec Soil test kit and will do a few tests tomorrow and will let you know the outcome.
cheers

[shanemartin]

Hi Shane,

I think the first thing to recognise is that we don’t actually have confirmation that the problem is ammonium toxicity or calcium deficiency, or both. It may well be something else. It could be a fungus, who knows? That’s why we have to keep an open mind.

We have a list of possibilities a few symptoms, but nothing really concrete to go on with. This is why a pH test is very important. Maples are sensitive to ammonia. If your pH has crept up to 7 or higher, than we can pretty much say it’s ammonia toxicity and a pH problem. If we are right, then adjusting the pH should give better growth. A Manutec soil pH test kit from the hardware or plant nursery is sufficient for testing the pH of your potting mixes. This either confirms or knocks off a possibility. If it’s pH related, we have to look at why it’s rising, is it your irrigation water alkalinity, or your fertilisers? Or something else?

Ammonium and plant physiology is rather complicated, and throwing in calcium makes it worse, my head hasn’t quite got around it yet. I’d like to know what the pH is before trying to guess if it’s something else.

Look forward to hearing what the pH is.
Regards
Paul
Hi Paul... excuse the edit, just conserving space.
A wealth of advice for this mind of mine to digest..... I have the Manutec Soil test kit and will do a few tests tomorrow and will let you know the outcome.
cheers

Hi Paul,

Did the soil tests today on the affected trees, and all came in with the exact pH of 5.5