John, I posted some pictures from our orchard on our website. The URL is:
www.holmbergorchards.com/basalcankers.htm I put up some pictures typical of what we have been seeing. The worst in the orchard are the macouns, but we have cortland, empire, and red delicious showing varying degrees of injury. We are going to try some inarch grafting this spring to rebound some of the severly girdled trees. Until now, we have simply been removing them. I also put up a picture of a scaffold limb showing what I assume is Botryosphaeria as well. We have seen a lot more of this in recent years as well, perhaps due to the increased inocculm from the basal cankers. Russell Holmberg Holmberg Orchards Gales Ferry, CT www.holmbergorchards.com ---------- Original Message ---------------------------------- From: "John L. Belisle" <[EMAIL PROTECTED]> Reply-To: "Apple-Crop" <[email protected]> Date: Sun, 18 Mar 2007 12:17:28 -0700 >I am wondering what your definition of trunk cankers and basal cankers are. >Are they two different problems? Does anyone have a photo???. Or a web >site showing the affliction. > >Bellewood acres > >JOHN BELISLE > > _____ > >From: [email protected] [mailto:[EMAIL PROTECTED] >On Behalf Of Mark Longstroth >Sent: Thursday, March 15, 2007 11:45 AM >To: Apple-Crop >Subject: RE: Apple-Crop: herbicide strategy > > >Thanks for your response Dave, >I had become convinced that something had changed in the commercial >formulations of glyphosate. >I saw too many trunk canker in orchards where glyphosate alone was used as a >stand alone weed treatment. >Are you using roundup? had become one of the first questions I would ask >when growers called about trunk cankers. >----------------------------------------- >Mark Longstroth >SW Michigan District Fruit Educator >Van Buren County MSU Extension >801 Hazen Street, Suite A >Paw Paw, MI 49079 >Bus (269) 657-7745 >Fax (269) 657-6678 >Email - [EMAIL PROTECTED] >Check Out My Webpages >http://web1.msue.msu.edu/vanburen/disthort.htm >----------------------------------------- > > >-----Original Message----- >From: [email protected] [mailto:[EMAIL PROTECTED] >Behalf Of Dave Rosenberger >Sent: Thursday, March 15, 2007 2:02 PM >To: [email protected] >Cc: Mike Fargione; Deborah Breth; Kevin Iungerman; Kerik Cox; Juliet E. >Carroll >Subject: Re: Apple-Crop: herbicide strategy > > > Here is a long response to Rick Holmgren's question relating to >contact herbicides that might cause basal trunk cankers on apple trees. > Concerns about contact herbicides causing basal cankers on apple >trees emerged in eastern New York beginning in 2001. We continued to >accumulate circumstantial evidence over the next five years that implicated >glyphosate as part of the problem. Mike Fargione and I published an article >(cited and linked below) outlining some of our observations. > >Rosenberger, D. A. and Fargione, M. J. 2004. Apple tree deaths attributable >to herbicides? Scaffolds Fruit Journal 13(13): 3-5. >http://www.nysaes.cornell.edu/ent/scafolds/2004/040615.html#diseases. > >Since that article was published in 2004, I have seen significant acreages >of Macoun apple trees destroyed as these basal trunk cankers completely >girdled some trees and damaged other trees so severely that they were not >longer productive. Other cultivars throughout New York State also showed >superficial bark damage that fit the same patterns, but most cultivars were >not so severely affected as Macoun. > Recently, I've become aware of additional information that may help >to further explain our observations. One agrichemical company rep told me >that from 2001 through 2005, many manufacturers/formulators of glyphosate >modified their original formulations by adding di-ammonium phosphate (or >di-ammonium phosphite?) so that these new formulations would work without >the addition of surfactant/penetrants that were recommended on the labels of >the earlier glyphosate formulations. Apparently the latest glyphosate >formulations that were released starting in 2005 moved away from using the >di-ammonium salt as an activator. > Over the past three months, I have been actively pursuing >information on disease control capabilities of the new phosphite fungicides >which are absorbed through tree bark and become fully systemic within trees >when applied to tree trunks. (This treatment process was developed in >California to treat trees for prevention of sudden oak death cause by >Phytophthora.) One representative of a phophite manufacturing company told >me that these products are highly systemic and will enhance uptake of any >other products that are applied with them. This rep said that his company >had tested various formulations of phosphites as activators for glyphosate. >He said that the phosphites being sold as fungicides are mostly composed of >mono-and dipotassium salts of phosphorous acid because the ammonium salts of >phosphorous acids sometimes caused phytotoxicity, at least in part because >of the ammonium salt's effectiveness as a desiccant. > I'm still not certain that I have the correct information on all of >the details related to changes in glyphosate formulations. However, it >seems possible that the trunk injury that we have observed on Macoun and >other trees over the past five years may be attributable to the ammonium >salts that were included in glyphosate formulations produced between 2001 >and 2005. That would make sense, because I've gone back through my notes for >the past 8 years and found no mention of herbicide-related trunk cankers >prior to 2001 despite the fact that glyphosate was being used in NY apple >orchards for many years before that. Furthermore, if the ammonium salts in >those glyphosate formulations contributed to desiccation of the sprayed >sections of apple trunks, that desiccation factor would fit perfectly with >my earlier hypothesis that something about the glyphosate injury was >enabling invasion by Botryosphaeria dothidea, a pathogen known to attack >drought-stressed woody plants. > The bottom line is that we probably will never be able to prove a >glyphosate/trunk canker association because no one has the time, funding, or >impetus to do the required research. However, IF the ammonium salts in >glyphosate were part of the problem, and IF those salts have now been >removed from newer glyphosate formulations, then the problem with basal >trunk cankers should gradually disappear. Trees damaged (presumptively) by >glyphosate sprays between 2001 and 2005 may take some time to recover, but I >would hope that we will not see new cases appearing in previously unaffected >orchards. > > >Greetings, > >I was wondering about what everyone was planning to do about an herbicide >program in the coming year. We are trying to move away from post-emergence >materials due to the possibility that they are leading to basal cankers in >our orchard. Last year, we switched from a glyphosate/gramoxone program to >a surflan+oryzalin application really early with a gramoxone touch-up in mid >summer. It worked okay, but we had some poison ivy and bittersweet >seedlings show up around september. Any thoughts or other ideas? > >Russell Holmberg >Holmberg Orchards > >Gales Ferry CT > > >-- >************************************************************** >Dave Rosenberger >Professor of Plant Pathology Office: 845-691-7231 >Cornell University's Hudson Valley Lab Fax: 845-691-2719 >P.O. Box 727, Highland, NY 12528 Cell: 845-594-3060 > http://www.nysaes.cornell.edu/pp/faculty/rosenberger/ > > > > ________________________________________________________________ Sent via the WebMail system at holmbergorchards.com --------------------------------------------------------------------------- The 'Apple-Crop' LISTSERV is sponsored by the Virtual Orchard <http://www.virtualorchard.net> and managed by Win Cowgill and Jon Clements <[EMAIL PROTECTED]>. Apple-Crop is not moderated. Therefore, the statements do not represent "official" opinions and the Virtual Orchard takes no responsibility for the content.
