Yea, at the time we talked about nectria as a possibility... I just found this- I bet that was nectria on black walnut....
http://images.google.com/imgres?imgurl=http://www.apsnet.org/online/Archive/1998/pdcovr15.jpg&imgrefurl=http://www.apsnet.org/online/Archive/1998/pdcvr15.htm&usg=__zAN_TvfMH-y02LdgRTKgwKGuSKs=&h=450&w=300&sz=223&hl=en&start=2&um=1&tbnid=84ffuqG_gNkMWM:&tbnh=127&tbnw=85&prev=/images%3Fq%3Dnectria%2Bcanker%2Bon%2Bblack%2Bwalnut%26hl%3Den%26rls%3Dcom.microsoft:en-us:IE-SearchBox%26rlz%3D1I7GZAZ_en%26sa%3DN%26um%3D1 ryan On Wed, Sep 30, 2009 at 9:31 PM, Jess Riddle <[email protected]> wrote: > > Ryan, > > The scar reminds me of a Nectria infection, but I'm no forest > pathologist. I can't see enough of the bark to be confident abount an > id. > > Jess > > On Wed, Sep 30, 2009 at 1:54 PM, Ryan McEwan <[email protected]> wrote: > > all, > > > > I found this tree in Dysart Woods many years ago. It was winter- no > twigs > > to be had (too tall)- and the bark, as you can see is deformed. > > > > Neither myself, nor a couple of pretty good fellow dendronerds that were > > along with me, could not come up with a positive ID for the tree, much > less > > the canker. > > > > My best guess was a butternut infected with the canker, but I am not > > confident at all about that ID. > > > > Can anyone confirm or reject this hypothesis based on the image? > > > > thanks > > ryan > > > > On Wed, Sep 30, 2009 at 10:09 AM, DON BERTOLETTE <[email protected]> > > wrote: > >> > >> Mike- > >> Regarding the butternut, I encountered them in Kentucky in the 1980s...I > >> suspect there are folks in this forum that can do a better job than I. > I'd > >> think that others might be interested in one that is seemingly vigorous > and > >> reproducing? It's a pretty pretty wood! > >> -Don > >> > >> > Date: Tue, 29 Sep 2009 08:51:08 -0700 > >> > Subject: [ENTS] Re: Marion Brooks Natural Area, Elk County, PA > >> > From: [email protected] > >> > To: [email protected] > >> > > >> > > >> > Don, > >> > It's quite rare around these parts, being pretty much confined to the > >> > lower Saint John river valley, around where I live. I've been trying > >> > to find as many as possible. I came across a nice one about a month > >> > ago growing on a small island in the Saint John river - it was > >> > absolutely loaded with nuts. > >> > What does the blight look like? > >> > > >> > Mike > >> > > >> > > >> > > >> > On Sep 28, 10:11 pm, Lee Frelich <[email protected]> wrote: > >> > > Don: > >> > > > >> > > You mean a positive reinforcement of negative effects. There are > >> > > plenty > >> > > of those involving shade and an allelopathic chemical, or changing > the > >> > > chemistry of the litter layer, say to a lower pH and then throwing > in > >> > > an > >> > > allelopathic chemical and shade (i.e. black walnut). Or making the > >> > > litter layer poor in nitrogen plus an allelopathic chemical and > shade > >> > > (Bracken fern), and all of the above smothering competition with > >> > > litterfall (e.g. sugar maple, the latter reinforces chemical and > >> > > resource changes with a physical effect). Trees keep out their > >> > > competition with multiple strategies. > >> > > > >> > > Lee > >> > > > >> > > DON BERTOLETTE wrote: > >> > > > Lee- > >> > > > Can you suggest an allelopathically positive effect (chemical > >> > > > combinations that turn out to be synergistic come to mind)? > >> > > > -Don > >> > > > >> > > > > Date: Thu, 24 Sep 2009 14:18:13 -0500 > >> > > > > From: [email protected] > >> > > > > To: [email protected] > >> > > > > Subject: [ENTS] Re: Marion Brooks Natural Area, Elk County, PA > >> > > > >> > > > > Don: > >> > > > >> > > > > Most ecologists take allelopathic to mean negative effects on > >> > > > > other > >> > > > > plant species. The plants that benefit could be either directly > >> > > > > and > >> > > > > positively affected by the allelopathic chemical (but this is > >> > > > unlikely), > >> > > > > or benefit indirectly by being insensitive to the allelopathic > >> > > > chemical, > >> > > > > but being freed from competition by removal of other species > >> > > > > sensitive > >> > > > > to the allelopathic chemicals (this is the most likely case, but > >> > > > > no > >> > > > proof). > >> > > > >> > > > > Lee > >> > > > >> > > > > DON BERTOLETTE wrote: > >> > > > > > Lee/Mike- > >> > > > > > In my time wandering through Kentucky woods, black walnut > trees > >> > > > > > were > >> > > > > > the only thing I saw that could alter the advance of a field > of > >> > > > > > poke > >> > > > > > salat! > >> > > > > > My question? What would negative allelopathic refer to? I can > >> > > > > > see > >> > > > > > that it would be positive in this case for black walnut and > >> > > > > > negative > >> > > > > > to most anything else, but I suspect it may refer to something > >> > > > > > else > >> > > > > > entirely? > >> > > > > > -Don > >> > > > >> > > > > > > Date: Thu, 24 Sep 2009 07:50:26 -0500 > >> > > > > > > From: [email protected] > >> > > > > > > To: [email protected] > >> > > > > > > Subject: [ENTS] Re: Marion Brooks Natural Area, Elk County, > PA > >> > > > >> > > > > > > Mike: > >> > > > >> > > > > > > We had a discussion a while ago on this topic, probably > before > >> > > > you were > >> > > > > > > on the list. Black walnut and butternut produce the > >> > > > > > > allelopathic > >> > > > > > > chemical juglone, which can stunt growth or even kill > certain > >> > > > > > > plant > >> > > > > > > species, although I have seen raspberries and a species of > >> > > > coneflower > >> > > > > > > (Rudbeckia triloba, the branched coneflower), growing under > >> > > > > > > black > >> > > > > > walnut > >> > > > > > > trees. > >> > > > >> > > > > > > Sugar maple and bracken fern have also been found to produce > >> > > > > > > allelopathic chemicals that reduce germination and growth of > >> > > > competing > >> > > > > > > plants. There are probably many other examples. > >> > > > >> > > > > > > Lee > >> > > >> -- > >> Ryan McEwan > >> The University of Dayton > >> http://academic.udayton.edu/RyanMcEwan > >> > >> > >> > >> > >> > >> >> > > > > > > -- Ryan McEwan The University of Dayton http://academic.udayton.edu/RyanMcEwan --~--~---------~--~----~------------~-------~--~----~ Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en To unsubscribe send email to [email protected] -~----------~----~----~----~------~----~------~--~---
