A possible example of Phytophthora infection in Mendocino County?



The suspect location is about four miles from the nearest confirmed infection.

As of February 2003, none of the tests performed on any of the suspect trees have come back positive.


Overall view of suspect
Overall view of suspect tanoak. It is about 30' from my house, with a liveoak to the right, another tanoak and a madrone (see below) to the left, and a water tank and outbuilding encroaching on its root space.


Sagging new growth
Sagging new growth. The tree is thick with these pale, comparably stunted sprouts, making it look brown instead of green.


Healthy new growth on neighbor
Healthy new growth on a tanoak about 50' away. The blossom parts and acorns are much larger, the sprouts not as numerous.


Sprouts around base
Sprouts ringing the base of the trunk. The trunk has been split here for a long time. It was obviously bleeding in the split and oozing in several other locations before the recent rainstorm, but that is hard to see now. The spots where the moss is dead are still visible near the top of the photo. The accessible bark seems sound, but I'm not sure how hard one should try to dig under it for beetle signs, so maybe I'm missing something.


Gall on trunk
An odd gall I hadn't noticed on the trunk before, maybe 18" off the ground, 3" across. There appear to be tunnels going under it, but maybe it is just craggy bark.


Lobed-leaf oak overall
An unhealthy madrone, about 20' from the suspect tanoak. All the web links I had found a couple of years ago about madrone afflictions seem to be gone, and most of the search results I find now are about Phytophthora. The damage looks like the descriptions of "madrone canker", except there are no extra growths or sunken areas, it just looks like the bark was burned.


Laurel with dead tips
The nearest Laurel tree, maybe 150' away, has just a few leaves with spots and dead tips. Most of the leaves are perfect.


Lobed-leaf oak overall
I'm not sure what species this is. It has non-spiny, smooth bright green leaves with lobes like eastern oaks. Most years it seems evergreen, but several times lately it has lost all leaves and appeared to be dead even during the summer. Right now it looks better than it has for many years.


Lobed-leaf oak overall
Leaves of the mystery oak.


Lobed-leaf oak overall
The bark of the mystery oak has "rotten" places (this is about 4" wide) which scrape off easily, exposing what look like beetle tunnels, and markings somewhat like the SOD web examples. I hadn't visited this tree before the rainstorm, but there is no obvious bleeding now.


For more information, please contact: loren (symbol) pacific (punctuation) net



Table of Contents - Frames
Table of Contents - Text

Revised 9 April 2003