Cedar Apple Rust Gall or PlayDough Hair?


"OK," I began, as I asked my kids an important question. "Who put the orange PlayDough hair on the cedar tree?" "Not me!" all 8 kids said in unison. And I believed them. But there was a gelatinous substance on the red cedar tree branches- and it turned out not to be PlayDough- but the Cedar Apple Rust Gall. (But, heaven help me, it did look like hair made from PlayDough.)

But really, I shouldn't joke about this freaky orange fungus. It is a terrible menace and scourge to apple tree farmers. Yes, I know I said this was a Cedar Rust Gall- but it doesn't harm the Cedar Tree- it harms nearby Apple Trees. How much harm you ask? So much so that the state of Virginia passed the following ordinance commanding the cutting down of any cedar tree found with a Cedar Rust gall that is within 1 mile of an Apple orchard. The law said as follows:

"Be it enacted by the general assembly of Virginia' that it shall hereafter be unlawful within this state for any person, firm or corporation to own, or keep alive and standing upon his or its premises, any red cedar tree, or trees (which are or may be) the source, harbor or host plant for the communicable plant disease commonly known as 'orange' or 'cedar rust', of the apple, and any such cedar trees when growing with a radius of one mile of any apple orchard in this state, are hereby declared a public nuisance and shall be destroyed as hereinafter provided, and it shall be the duty of the owner or owners of any such cedar trees to destroy the same as soon as they are directed to do so by
the state entomologist, as hereinafter provided."


Not impressed yet by this funny fungus? Consider the following quote from the Oklahoma Cooperative Extension Service: The disease cycle of cedar-apple rust is one of the most complex of any plant diseases, and the fungus (Gymnosporangium) that causes cedar-apple rust spends almost two years of its life cycle on the cedar trees (Figure 5). The article and the life cycle diagram of this tree can be seen here: Oklahoma State Extension Office


So, what does this fungus do to the apple trees that would cause such consternation among apple farmers? Well, according to a Mississippi State Extension report- the fungus causes the following damage: While cedar-apple rust doesn't kill trees, the repeated effects of leaf destruction and defoliation eventually leads to weakened trees and poor apple yields. Weak trees are more susceptible to other problems, such as winter injury, which frequently lead to tree death. Hmm, I'm going to guess that apple tree farmers would rather their apple trees not die. The following is 1919 account of a farmer dealing with the Cedar Apple Rust:


Text not available
Transactions of Th Annual Session of the Peninsula Horticultural Society By Peninsula Horticultural Society

9 comments:

...Kat said...

poor poor cedar trees

Lynda Lehmann said...

It's rather a pretty fungus. Too bad it wreaks such destruction on the poor apple trees!

Chris said...

WOW, what neat historical facts. Too bad for both trees! And yes it really looks like playdough, like the kind I use to find embedded in my carpet!

blueblue said...

Ick, it kinda looks like something from the prop department of a B grade science movie.
Sorry about your trees.

Diane said...

Very nice (if creepy crawly) blog! Found you via Blogcatalog and I will be back!

Carolyn Hietala said...

What a super post... I have learned so much. Thanks!

Nature Nut /JJ Loch said...

Daniel,

It's the first time I've seen cedar apple rust and I would have thought it was PlayDough too. Thanks for the great photo and post! I have some apple trees with rust, and Jeff has been trying to spray it away. We'll have to do some research.

JJ :D

Fruit species said...

Those parasites are beautiful but are destructive too. They got to go, they got to go!
Fruity

The Giraffe Head Tree said...

Ah yes, the dreaded cedar apple rust. While the apple farmers understandably hate it it's a part of nature that cannot be denied. But don't you wonder exactly what its function really is? Is it beneficial in some manner? Does it harbor the necessary chemical to cure cancer or MS? Hm. It's too late in the day to get that deep....