Thursday, June 9, 2011

What's this?

This is a very old collected mugo pine, Pinus mugo. It has been a bonsai since more than twenty years, always happy and throwing nice and healthy new needles. This year all of a sudden this. The tree seems healthy otherwise. There are more than 150 other pine trees in my garden. Not a single one has anything like this. What is it? What can I do against it?


Pedro Inacio said...

Hello Walter,

I'm not an expert on mugo pine diceases, but in my opinion probably it can be due to any of the following:

- herbicide damage (symptoms occur a few days to several weeks after herbicide application);

- curly needle syndrome is induced by water stress during needle elongation and suggest that wetting the foliage decreases the strength of the fascicle sheaths;

- Elytroderma deformans, a fungus. Symptoms occur in the spring when groups of year-old needles turn reddish-brown except for the base. Needles usually drop by October.

Hope that helps your investigation.


Pedro Inacio

Walter Pall said...

Thanks Pedro,

herbicide is possible, but I sprayed lots of pines a the same time which don't show any signs. Someone suggests Rhyacionia buoliana. Could well be. I will cut a pice off and see whether there is a worm underneath.

Captain Haddock said...

I have similarly deformed needles on some of my scots pines. in my case it is definately not herbicide related. I was looking at nutrition or maybe water stress. Please do tell if you discover the cause.

Anonymous said...

This look more pathogenic than water stress, best thing to do is contact your local forest Botanist or ask a mugo pine cultivator. they should identify this is no time. dont stress unless its dead!

Anonymous said...

Walter, this is not directly related to your problem, but you should think about buying a used stereomicroscope (Zeiss Stemi).

Anonymous said...

In my experience this (contorted needles on new shoots) can happen if untimely pruning is combined with warm overwintering. Given your experience and reputation, I don't think that's the case, but I just thought I ought to have mentioned it.

Ryan said...

Walter, I have a Japanese black pine that is doing exactly the same thing. It does not appear to have a disease. Most biotic pathogens do not leave uniform symptoms, however abiotic diseases (such as water or salt stress) is more uniform. If this is happening to all the new buds on this tree, I would say it is due to abiotic stress of some sort. However, the needles still appear to look normal(straight) and healthy once they've cleared the fascicle sheaths, much like mine. I am well aware of your watering and fertilizer regimen but it is possible that this tree did not get as much overhead watering this year or late last year?
p.s. I can email you pictures of the buds on my pine that I believe have the same appearance if you would like.

Walter Pall said...


thank yo.
Please send pictures of your JBP.

Walter Pall said...

Ryan sent me his pictures and it looks very similar what I have. Since no other pine out of several hundred has anything like this it must be some individual thing. It is possible that this special tree did not get watered enough for a couple of days in early spring. At the moment the needles are still contorted, but look healthy otherwise. I believe the tree will survive and hopefully throw normal growth next year.