Pine-pine gall rust on shore pine
Pine-pine gall rust or western gall rust is found throughout North America on two- and three-needle species of pine (Pinus spp.).
Photographed along the boardwalk in Burns Bog on a shore pine (Pinus contorta var. contorta), this image shows a sporulating gall. The swelling of the branch that causes the gall started somewhere 2-4 years prior to this photograph being taken, when a nearby gall at this stage released its spores and one landed here when this branch was young. As the spore divided and grew into a mature rust fungus, it resulted in hormonal responses leading to hyperplasia (or increased cell proliferation), i.e., the formation of the gall.
Unlike many other rusts, western gall rust is autoecious, meaning it does not have an alternate host species (compare with white pine blister rust, which requires gooseberries as alternate hosts). Transmission is directly from pine tree to pine tree. Fortunately for natural stands, it has low lethality on established trees. However, it can be economically damaging in plantations or managed forests by decreasing wood volume through malformation (or in the case of Christmas tree farms, unsightly blemishes). As noted in the High Plains Integrated Pest Management Guide, it has the property of being very difficult to control “due to its high rate of infection and the latency period between infection and expression of the symptoms”, which sounds grimly familiar.
The Plant Disease Diagnostic Clinic of Cornell University has an excellent factsheet on pine-pine gall rust, while Forestryimages.org presently has 63 images of it and its expression in pine trees, including some images of young stems and established trunks with galls and burls.
Lastly, in UBC Botanical Garden news: the staff have collectively been making an effort to share more about plants and the Garden during this time. In addition to Botany Photo of the Day, also check out our gardening and plant help forums, our Instagram feed, or our being-revitalized Youtube channel.
Just released in the past 24 hours on Youtube, we have a previous year’s performance from a former artist-in-residence and a 360-degree virtual tour of the Greenheart Treewalk, both filmed in the David C. Lam Asian Garden. We hope in some small way this helps you to experience the health and wellness benefits of visiting a BC rainforest without leaving your home:
Hi Daniel:
Great to see a photo of a disease as opposed to mostly describing flowers. Please can we have more photos of various diseases on plants/trees and perhaps insects that are attracted to plants/trees, etc?
Thanks,
Anne
Hi Anne,
Thanks for the comment. So much depends on what images I have available to me–I’m presently just sharing mine, but even contributed photographs rarely feature diseases / insects. While I have a large library of images, I have to say I lean strongly toward pretty flowers. But I do have some… I’ll make more of an effort.
Hi Daniel,
I especially appreciated this post as I am now living on acreage where many western white pine and shore pine are growing, and there are a lot of ugly lumps on the branches of the younger shore pines.
I too would appreciate more photos and posts that feature pests and diseases, particularly those that afflict the native trees and shrubs in the Pacific Northwest.
Thank you,
Ann
I’m glad to read that you want to share more about the garden. Could we have photos of the trees in the Peter Wharton Cherry Grove, please? Some of the trees are surely in bloom now. Replies in this thread would be good:
https://forums.botanicalgarden.ubc.ca/threads/ornamental-cherries-at-ubcbg-2020.97128/ (there’s only one posting this year),
and sure, on Instagram. Thank you.
And thank you for continuing these postings.
I should clarify — almost all of us, with the exception of a subset of the horticulturists, are working from home. We are sharing content we already have on hand.
Hi. I am on PEI and have watched the white pine blister rust and the white pine beetle malform many trees over the years. Always plantation trees, planted in full sun.
I have a pest in my garden – horsetail. It came in with some purchased compost and in two years has taken over 1/3 of the garden which is 100 feet by 100 feet, started in 1995. All hand dug raised beds.
Any ideas on eradication? I read last fall, too late to try as snow blanketed the area, to heavily lime the area, then two weeks later heavily fertilize it. Then keep repeating this cycle….until it decides it is not welcome. This will make the garden inhospitable to everything else, and can take five years! According to the source. If I do nothing it will completely take over. I saw another garden last year that was totally taken over. They are not sure how the plant got to them, it is also an old garden.
Any ideas would be appreciated. I dug last year…..for days….two feet deep trenches and sifted out roots. This is not practical, and was ineffective. Thanks for listening!
Hi Ruth,
This has been a much-discussed issue over the years. Have a look at this thread on the forums, started in 2005 with the most recent reply in 2019!