What do you think of this black pine needle?

bonhe

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I just want to share with you these signs on one of my JBP' s needles. It is only in one small branch on the top and one on the middle of the tree. Any suggestion? Thanks.
IMG_6106.jpg IMG_6109.jpg IMG_6113.jpg IMG_6116.jpg IMG_6117.jpg IMG_6119.jpg IMG_6120.jpg IMG_6104.jpg IMG_6105.jpg
Bonhe
 

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AlainK

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Never seen that before, but to me, it looks like a fungal problem. I'd eliminate the sick needle(s) and spray the tree with some adequate (?) treatment.
 

AlainK

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Thanks for the link - that I hadn't seen before.

Elegant, dynamic but at the same time cautious and down-to-earth, easy to read handwriting.

:cool:

What's more, very good job, the kind of work that deserves to be labelled somewhere on the site as "resources" or something, like documents about soil, treatments, etc.

I'll translate it for the members of my club, and we won't pay anything for that! :p

Mais merci, c'est une contribution très utile (do I need to translate?...)

OK : "très utile" : "very helpful/useful" (Latin: utilis, which gave "tool" in E. and "outil" -tool- and "utile" in F.)
 

0soyoung

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Thanks for the link - that I hadn't seen before.

Elegant, dynamic but at the same time cautious and down-to-earth, easy to read handwriting.

:cool:

What's more, very good job, the kind of work that deserves to be labelled somewhere on the site as "resources" or something, like documents about soil, treatments, etc.

I'll translate it for the members of my club, and we won't pay anything for that! :p

Mais merci, c'est une contribution très utile (do I need to translate?...)

OK : "très utile" : "very helpful/useful" (Latin: utilis, which gave "tool" in E. and "outil" -tool- and "utile" in F.)
It was the most valuable thing when I first saw it in a post maybe 10 years ago now. I had to lean all over prevail upon @bonhe to post it as a Resource (its the 9th in the list presently). It is still the single best resource for any/all pine growers, IMHO.
 

bonhe

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Mais merci, c'est une contribution très utile (do I need to translate?...)

OK : "très utile" : "very helpful/useful" (Latin: utilis, which gave "tool" in E. and "outil" -tool- and "utile" in F.)
Thank you very much for your kind words, AlainK.
I could read some French, but can not speak! :rolleyes:

It was the most valuable thing when I first saw it in a post maybe 10 years ago now. I had to lean all over prevail upon @bonhe to post it as a Resource (its the 9th in the list presently). It is still the single best resource for any/all pine growers, IMHO.
Thanks Osoyoung. I am planning to update this diagram soon.
Bonhe
 

bonhe

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Hi AlainK and Osoyoung,
Both of you are correct about fungal infection here. It is Diplodia tip blight.
Yes, some closed up pictures show the lines of stomata and little black things are fungal fruiting bodies called pycnidia. Pycnidia will rupture into the tiny spores called conidia. With my power magnify glass, I don't think we can see spores.
It is interesting that I can see the 2 fungal fruiting bodies on the surface of resin droplet!. One needle has multiple resin droplets.
If you pay attention to the 7th and 8th pictures, you clearly see the difference of normal (hydrated) and abnormal area (dehydrated)
Management? Primary prevention is much better than treatment. However, I think the practice of primary or secondary prevention will be very difficult for us who do bonsai. The reason? Because the fungus can not only attack to the stressed tree but also can infect wounded tissues. Most of us prune of JBP in late spring or early summer which is also the best season for fungal growth. The fresh wounds from pruning make the tree most susceptible to fungal attack.
Yes, we have to remove the sick needles and apply fungicides to the tree at late winter (budbreak), mid spring and late spring.
Bonhe
 

bonhe

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Because this is the fungal season, I'd like to bring this topic up again for whoever needed info.
Thụ Thoại
 
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