Re: [IUFRO RG 7.02 FORPATH] Oozing Black Spots on Limbs of White Oak

Dear Enrico It is very good to hear from you, thanks for sending nice photographs. Is this on Quercus robur? I have seen very similar symptoms in the UK on Q. robur although weeps from the lower region of stem branches. Although these type of symptoms are not typical of AOD (Acute Oak Decline), the cankers and weeps tested positive for the AOD bacteria and so we assign the cause of the cankers to bacteria. Do you know if there is any insect association with the cankers in Ohio? We could send you swabs, you could swab affected trees and post them back to us for RT-PCR assessment for AOD bacteria, if that is of help to you. Additionally, there is an apparent emergence of Drippy blight in Colorado (Lonsdalea quercina). I think it would be useful to test for that in the case you mention in Ohio, it could be important. Rachel Sitz and Ian Pearse are contacts for this expertise (Rachael.Sitz@colostate.edu<mailto:Rachael.Sitz@colostate.edu>; ianspearse@gmail.com<mailto:ianspearse@gmail.com>). I hope this is helpful, Best wishes, Sandra Dr Sandra Denman Principal – Oak Declines: Senior Pathologist Centre for Ecosystems Society and Biosecurity Forest Research Alice Holt Lodge Gravel Hill Road Farnham GU10 4LH Tel: 0300 067 5640 Email:sandra.denman@forestry.gsi.gov.uk https://www.forestry.gov.uk/fr/INFD-84RB3W From: rg70300-forent [mailto:rg70300-forent-bounces@lists.iufro.org] On Behalf Of Bonello, Enrico Sent: 17 November 2018 18:49 To: rg70200-forpath(a)lists.iufro.org; IUFRO RG 7.03.00 Subject: [IUFRO RG 7.03 FORENT] Fwd: Oozing Black Spots on Limbs of White Oak Importance: High Hello forpathers and forenters, Below are a couple of pictures sent to me by a local arborist, wondering what’s going on on the main limbs of a white oak. I am contacting you because I find that this kind of very localized bark discoloration/staining is quite common in oaks. I’ve always suspected these were very small, localized infections by some species of Phytophthora, like citricola, citrophthora, etc. but I’ve never verified. Whatever it is, it seems to me it never goes anywhere, i.e. the lesions remain very small and do not have any serious impact on the host. Does anyone else actually know what these are? It would be of great interest to me personally, in addition to providing an answer to the arborist. Cheers! Enrico [cid:image001.jpg@01D47FE8.F02D0710] Pierluigi (Enrico) Bonello Professor Department of Plant Pathology 201 Kottman Hall | 2021 Coffey Road Columbus, OH 43210 614-688-5401 Office | 614-292-4455 Fax bonello.2@osu.edu<mailto:bonello.2@osu.edu> | http://plantpath.osu.edu/bonello Center for Applied Plant Sciences | http://caps.osu.edu Translational Plant Sciences Graduate Program | http://tpsgp.osu.edu Environmental Science Graduate Program | http://esgp.osu.edu/ Infectious Diseases Institute | https://idi.osu.edu/ The STEAM Factory | https://steamfactory.osu.edu/ [cid:image002.jpg@01D47FE8.F02D0710][cid:image003.jpg@01D47FE8.F02D0710] ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please visit http://www.symanteccloud.com ______________________________________________________________________ +++++ The Forestry Commission's computer systems may be monitored and communications carried out on them recorded, to secure the effective operation of the system and for other lawful purposes. +++++ The original of this email was scanned for viruses by the Government Secure Intranet (GSi) virus scanning service supplied exclusively by Cable & Wireless in partnership with MessageLabs. On leaving the GSi this email was certified virus-free