The MGS Forum
Gardening in mediterranean climates => Pests and diseases => Topic started by: MikeHardman on June 25, 2013, 04:00:49 PM
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My lime tree (Citrus, not Tilia) is getting some dieback on small shoots. The dieback sometimes stops where the shoot meets the parent branch, but sometimes it does not - the parent branch gets infected too. I have cut off the infected shoots. I noted there was no discolouration inside - no brown marking.
The other parts of the tree are healthy (apart from some citrus leaf miner), and new shoots are appearing in many places (which are showing no signs of infection).
It suggests a fungal infection to me.
What is the problem?
What should I do about it?
Thanks for your thoughts,
Mike
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Mike, I wonder whether it could simply be cold damage. Limes are susceptible to that, particularly young plants. If the shoots are damaged by cold, a bacterial rot (that wouldn't normally affect healthy shoots) could follow. The leaves don't show any particular signs of rot, so much as the symptoms of weather damage.
The fact that your tree seems to have plenty of healthy new shoots is very reassuring.
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Thanks Alisdair; I'll look into that possibility.
The symptoms are different from those mentioned here
http://www.tropicamango.com/freezedamagecare.html
But that page deals with frost/freezing damage, and mine would barely have suffered that (though we did get just a little snow).
Some fruits from my research in-progress...
There's a good page on citrus problems here
- http://www.ipm.ucdavis.edu/PMG/C107/m107bpleaftwigdis.html
That pointed somewhat towards anthracnose, but some of the symptoms don't match.
Useful list here, too
- http://en.wikipedia.org/wiki/List_of_citrus_diseases
I note that limes suffer from the witches' broom disease of lime (WBDL), caused by Candidatus Phytoplasma aurantifolia; see:
- http://www.ncbi.nlm.nih.gov/pubmed/21534492
- http://www.flickr.com/photos/horticulture/2326582306/
- http://ufdcimages.uflib.ufl.edu/IR/00/00/30/23/00001/PP15000.pdf
At least superficially, that looks like my tree's symptoms, and there are quite a few trees in local citrus groves that have similar patches of dieback. But fortunately I see no signs of the proliferation - no witches brooms as such - and I hope I don't see them; I hope it is not this.
More on phytoplasma in general here - http://en.wikipedia.org/wiki/Phytoplasma
Tristeza disease also seems to be a possibility. Again I hope my tree does not have that.
http://www.ipm.ucdavis.edu/PMG/r107101311.html
So - no answer yet, and all opinions welcome...
Mike
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Your leaves don't show anthracnose symptoms. Tristeza would probably show marked vein clearing and stem pitting on your lime; I can't see that in your photos. So (fingers crossed that it isn't Tristeza, which I know has been a problem in Cyprus in the past!) my money - and hope - would still be on its being cold damage.
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Thank you Alisdair.
I shall keep an eye on it and hopefully post in due course to say 'it is fine now'.
Cheers,
Mike
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Hi Mike
How's your tree doing now?
I think our lime tree suffered dieback from cold while we were away in February, although we don't really get frost down here in southern crete. It is thriving now, but wondered how I should protect it next winter...really want to grow my own limes!
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Kriticat,
Thanks for prompting me to reply.
My lime is fine now. Last year, in fact, the dieback ceased about when I posted. I noticed no other symptoms.
Later, I nipped-off the affected twigs, and it is fine now.
Mike