Of All The Gall: Part Three

Abnormal foliage associated with Rose Rossette Disease on Multiflora Rose

We were hiking at a friend’s place this spring when I noticed that, not uncommonly, the Multiflora Rose in their clearings did not look right.

On many but not all bushes, one or more canes bore leaves that were withered-looking, sometimes red-colored, sometimes green, but definitely odd and much like the “witches broom” condition that is sometimes observed as a disease response in other plants.

I had written hopefully about this plant pathogen back in 2007, but only now had I seen Rose Rosette Disease through my camera lens–a potential solution to the rampant spread of Multiflora Rose.

The pathogen (that is being attributed to a virus, but none has been identified) is transmitted by certain wind-borne mites. The mites live inside the galls we see mostly on elms. We observed these mite galls on my friends property the same day my eyes were opened to the presence of RRD in Floyd County.

And now I am aware of it, I see it everywhere while driving the backroads, some places more than others. Often, once you know to look for it, you’ll see rose bushes that would have been impossible to clear along a fenceline that have totally succumbed, their arching canes brittle and leafless. Makes me giggle.

But this is a mixed blessing: The pathogen also does its work on ornamental roses. So if you’re a rose fancier, you might want to scout your area for the gall mites on your property (or sneak onto your neighbors at night with a flashlight and pair of stout loppers). Truth is, I don’t think there’s much to be done for prevention; destroy diseased roses after the damage is done.

Contrarywise, if MF Rose is a problem on your property, I wonder if “transplanting” gall mite-infested elm branches at just the right point of maturity of the mites could intentionally infect an otherwise uninfected pasture rose plant or group of plants.

So that’s the end of the story–for now–and one in which a problem-invasive at last meets with a natural control to keep it in check. But you know how these “solutions” sometimes turn into problems. So stay tuned!

 

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Published by fred

Fred First holds masters degrees in Vertebrate Zoology and physical therapy, and has been a biology teacher and physical therapist by profession. He moved to southwest Virginia in 1975 and to Floyd County in 1997. He maintains a daily photo-blog, broadcasts essays on the Roanoke NPR station, and contributes regular columns for the Floyd Press and Roanoke's Star Sentinel. His two non-fiction books, Slow Road Home and his recent What We Hold in Our Hands, celebrate the riches that we possess in our families and communities, our natural bounty, social capital and Appalachian cultures old and new. He has served on the Jacksonville Center Board of Directors and is newly active in the Sustain Floyd organization. He lives in northeastern Floyd County on the headwaters of the Roanoke River.

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1 Comment

  1. Fred – RRD was introduced into Floyd (Poor Mtn, actually) 7 or 8 years ago by an anonymous friend who imported it from Ohio. The mites live in the infected tips. To “move” it, you just need to cut the last foot or so from the plant and just place them on uninfected plants. I’ve eliminated about 20 acres of MF on my farm, but still actively maintain some infected plants just to give tips to friends and ensure the disease retains a presence on the farm.

    You can protect grandma’s tea roses by using a miticide. There’s really no other way that I know of given that RRD is now spreading rapidly to all corners of Floyd (thankfully, in my opinion).

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