AusBonsai

Hi all,

After any help in diagnosing this problem which has recently appeared quite extensively over two relatively established JBPs.

First noticed as some needle pairs going brown from half way along, right out to the tips. Didn't appear to be three year old needles, so I don't think it was usual needle attrition.

Upon closer inspection, there are lighter spots along much of the length of needles, relatively all over the trees. At the tips, some die off and blacker looking spots. These are not scale, unable to be scratched off.

Fungal? Apart from a generic fungal spray, any ideas?

Have looked through prior posts, but the consensus seems to be that many things can look the same and diagnosis is only really available with actual pics of the problem in question.

Many thanks!

It is difficult to diagnose these types of things.

A few points to consider..

1/ Hail damage from months ago?

2/ Insect damage while the needles were still very tender? - less likely

3/ A problem with the roots - too wet? Root tips dead or dying or damaged in the past even if ok now?

4/ Some kind of fungal infection during the tender needle stage? - Less likely

5/ Damage from some kind of spray?

6/ Throwing crushed scoria at the tree because you were mad with it?

I'm leaning toward a combination of 1 and 3.

treeman wrote:It is difficult to diagnose these types of things.

A few points to consider..

1/ Hail damage from months ago?

2/ Insect damage while the needles were still very tender? - less likely

3/ A problem with the roots - too wet? Root tips dead or dying or damaged in the past even if ok now?

4/ Some kind of fungal infection during the tender needle stage? - Less likely

5/ Damage from some kind of spray?

6/ Throwing crushed scoria at the tree because you were mad with it?

I'm leaning toward a combination of 1 and 3.

No 6. I just laughed loud enough for my dog Hadley (a black mini-schnauzer) to raise his head as if to say 'Hey, I'm sleeping here and why are you laughing at that screen?'

On No.1 - Hail Damage - it pays to keep a close eye on your plants. I tend a few cymbidium orchids ... a bit like my bonsai, I know most of them very well. It helped me because I was able to immediately see the hail damage. Whilst it was/is ugly - I know it's not a disease. I am not saying yours is hail damage for sure but the last two photos look like orchid leaves in miniature; perhaps hail could be a culprit?

Koside blue,copper based fugiside, don’t get on your soil it will kill the good fungus

I agree with everything Treeman has said, as it could be all of these things, or a combination.

It looks like it might be Dothistroma Needle Blight - a fungal disease.
Peter H is right that Kocide blue would fix this. I have used Mancozeb (NOT Macozeb plus) to successfully treat
this in the past. With either of these fungicides, do as peterH suggests, and cover your soil before spraying to avoid
killing any mycorrhiza in your soil.

Here is a link to an article from Oklahoma State Uni extension service which covers this, although not specifically for
bonsai, and includes more pics to help identify if this is the problem you are experiencing.

http://factsheets.okstate.edu/documents ... t-of-pine/

Leong Kwong's book on Black Pines also shows pics of this disease, and advises the use of fungicide.

Good luck

Initially I thought maybe dothostroma too but that shows up as rings right around the needle (take a close look at Juniper blues photos) None of the spots on Nate's tree have formed rings, just round spots so probably not dothostroma in this case.
Foliar fungicide should not do any harm and may even help if this is some other sort of fungal infection.

Thanks brains trust. Really appreciate your experience.

Will try the recommended fungicide and cover the soil when spraying and until the needles have stopped dripping.

The first two pics were in evidence for a while now. The second two only in the last two weeks. With the latter, it is possible that they just got beaten up during our house move, but they would be pretty weird injuries to be sustained, so I think it is a problem.

Will let you know how I go.


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I go with treemans #1

i had almost an exact looking issue that we talked about in a previous thread with about 4 of 10 of my black pines and after pulling the tree out it was root rot.

3 died, 1 survived. It always for me seems to be either this time of year (Maybe due to not enough air getting into the roots and the wet winter) or 6-8 weeks after candle cutting perhaps as too much water and soil not draining well enough as they require less water after a candle cut.

In 1 of the tree's it had a similar pattern before going like the one in the photo below.

viewtopic.php?f=131&t=23802

hope you win the battle keep us updated.

correction #3 lol