Yellowing needles on Japanese Black Pine

Puffermash

Hi All,

My little Japanese Black Pine is developing yellow/brown dots in the middle of some needles. From that yellow/brown dot, the yellowing spreads to the end of the needle so that half the needle is yellow/brown while the first half remains green.

I would like to know what is causing this? Is it dehydration, or heat, or what??

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bwaynef

I've noticed that on a few of my JBPs. It's pretty limited in scope on mine so I'm not worried a whole lot. I thought it was some trauma inflicted on the needle at that point, causing the remaining portion of the needle to die. It'd be interesting to know of any other cause.

<edit> 900th post</edit>

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cray13

I have a couple of JBP as well and have noticed these yellow areas with brown spots.


Does it look like the spots in the image below? If so this is apparently "Brown Spot Needle Blight".

I found this image with some pretty good info at

http://www.ces.ncsu.edu/depts/pp/no...odin19/od19.htm

Go to the link above and about half way down the page you'll find a description of this disease and suggestions on how to treat it.

From the link above:
"Fungicide applications of Bordeaux mixture, maneb or chlorothalonil are effective in preventing infection. These fungicides are registered for use on longleaf, but not on Japanese black."

I'm not sure what they mean by not being "registered" for JBP. Maybe a little more research will reveal an alternative for JBP.

I haven't treated my trees because the affected areas were very small and have disappeared.

Attached Images

brownspot3.jpg (12.8 KB, 30 views)

bwaynef

That isn't what I'm experiencign cray. Working out from the branch, the needle is green. Then, usually about half-way out but not always, theres a small dark line; brownish. On the opposite side of the line, the needle is yellow all the way out to the tip.

I'm assuming thats what the OP sees too. Like I said, I chalked it up to trauma to the needle, as if it were bent sharply at that point.

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Globalist1789

Pine needles don't last for ever. Now that it is fall, the oldest needles might be shedding. I don't recall how many years JBP needles hold on for (2 I think). So if it is the oldest needles then there isn't anything to worry about.

bwaynef

Sorry to take over this thread, but my curiosity is piqued.

I don't think its shedding its needles. The affected needles last for a good long while, though my experience has been that the affected PARTS of the needles generally fall off eventually.

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© 2004 - present bwaynef

Graydon

Congratulations on the 900th post!

It would be interesting to see some photos of you needles, as well as some from puffermash. It's really hard to describe problems let alone diagnose without photos. I too have some needle issues with some of my pines, but it is concentrated on only a few trees and just a couple of branches on those trees. Much like what you describe.

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cray13

I agree with Graydon. We probably need to see some images of Puffermash's needles to really tell. But the quote above sure sounds a lot like what bwaynef has described.

ALDEVAUX

Yes, you are quite right, because it is also sometimes very hard to diagnose a plant disease even when you see the affected plant in front of you, or when you have a specimen of the affected parts in your hands.
A close up pic of the affected parts is also needed for a surer diagnosis.