The first response sent too quick by mistake, here is the complete email———
Doug-I looked at the photos you attached and the last photo, #22301 (see below) at the base just above the rootstock- has long vertical cankers (sunken areas in the bark) and verticle cracking in the bark. Combined with the tree collapsing it sure appears to be fireblight. Mo Tougas echoed this question. However you also appear to have significant damage to the rootstock just below the graft union when you blow the picture up. Its weedy and from the angle cannot see how much is compromised. This can be caused by herbicide, mechanical injury, winter injury or all the above and could contribute to tree collapse. I had emailed you a list of questions on this list but I didn't get a response. (See list below from July 18 email.) The purpose was to try and narrow down whats going on. You have had much advice, from many on the list. The main question is what rootstock is you're planting on? If is a susceptible stock with a susceptible root then you have double trouble.The fireblight can run right to the root causing tree collapse. With those cankers visible in the lower trunk this looks like what you have. My guidance to growers with this combination, susceptible stock with susceptible root is take the tree(s) out. You also indicated these were in clusters, again sounds like fireblight, the inoculumn moves to the trees next door and take it out. The soil born disease phytophora can cause a similar looking tree collapse, but will not have the cankers in the trunk. Also is born in the soil water and usually runs down a row if there is any slope. There are many good labs, both Univ. and private that can id both fireblight and phytophora if the get live tissue samples. You need to confirm what you have so you can plan control programs. I would remove all infected trees and burn, sample for lab first- Check trees for FB cankers and remove if you find. There are spray programs to harden off fireblight shootblight. Certainly both shootblight and blossom blight programs should be implemented next year beginingbeginning with copper sprays very early, Apogee program beginning at Pink for shoot blight, and blossom blight using Newa or forecasting programs to predict spray applications of antibiotics and SAR products until all bloom is gone, and then post bloom control programs. See also our fact sheet that covers all these pieces for control: An Annual Fire Blight Management Program for Apples https://ag.umass.edu/fruit/fact-sheets/annual-fire-blight-management-program-for-apples If you wish do discuss in detail please contact me. Best, Win Win Cowgill Apple-Crop co-founder Professor Emeritus, Rutgers, the State University Visiting Scholar, UMASS-Amherst CEO- Win Enterprises International, LLC Editor Horticultural News PO Box 143 Baptistown, NJ 08803 Office 908-489-1476 Fax- 908-996-6404 Email: wincowg...@mac.com www.wincowgill.com www.virtualorchard.net/ http://giselacherry.com/ http://virtualorchard.net/njfruitfocus/index.html http://www.appletesters.net http://nc140.org Twitter @mrsuncrisp <https://twitter.com/mrsuncrisp> > On Jul 20, 2018, at 11:16 PM, Doug Nelson <doug.nel...@nelsonmultimedia.com > <mailto:doug.nel...@nelsonmultimedia.com>> wrote: > > hugh makes me think i dont have fire blight given his description. What I > have happening is clusters of trees (about 4 or 5 per cluster in 3 different > clusters) across my 6000 tree orchard. When the tree becomes symptomatic all > the leaves brown and the entire tree seems to dies withing 5 days- all the > leaves become droopy then brown at once. Maybe this is something else > happening? Attached are pictures. > > > > > > On Thu, Jul 19, 2018 at 7:45 AM Kari Peter <ka...@psu.edu > <mailto:ka...@psu.edu>> wrote: > Pruning out fire blight this time of year can be tricky depending how much > fire blight you are pruning out. Excessive pruning will encourage more shoot > growth = more shoot growth means susceptible shoots to fire blight right now > especially with conditions favorable for disease. Trees should be hardened > off right now meaning new shoot growth should be finished. When this occurs, > the bacteria stops moving in the trees and new fire blight incidence should > stop. I would highly recommend avoiding doing anything that would encourage > new shoot growth right now. If it were me, I would just wait until the > dormant period to aggressively remove everything. There is much debate about > cleaning pruning shears between cuts. I don’t recommend it because the > bacteria can move 3 feet beyond the site of visible infection, so > disinfesting is a moot point. Here is my latest article (June 26, 2018) in > Penn State Fruit Times about what to do about fire blight now (it’s just > below the info about apple scab): > > > > https://extension.psu.edu/mid-season-tree-fruit-disease-update > <https://extension.psu.edu/mid-season-tree-fruit-disease-update> > > > And a note: do not spray any streptomycin. Streptomycin is for bloom time > only, and after a trauma event, such as hail. Do not spray it beyond these > times. If you are concerned about new shoot growth (if this is a new orchard > pushing right now), I would recommend Cueva to limit spread of shoot blight. > > > > Kari Peter, Ph.D. > Assistant Research Professor - Tree Fruit Pathology > Department of Plant Pathology and Environmental Microbiology > Penn State Fruit Research and Extension Center > 290 University Dr., P.O. Box 330 > Biglerville, PA 17307-0330 > > > Office: 717-677-6116 Ext. 223 > Fax: 717-677-4112 > E-mail: ka...@psu.edu > <https://webmail.psu.edu/webmail/shell.cgi?timestamp=1362517824> > Twitter: https://twitter.com/drtreefruit <https://twitter.com/drtreefruit> > > > On Jul 18, 2018, at 10:24 PM, "wincowg...@centurylink.net > <mailto:wincowg...@centurylink.net>" <wincowg...@centurylink.net > <mailto:wincowg...@centurylink.net>> wrote: > > Doug- where are you located? > > What rootstock(s)? > > What cultivars? > > How old are the trees in your tall spindle? > > What was your fireblight control program at bloom? > > any post bloom program(s) > > > > Win > > > > On Jul 18, 2018, at 9:26 PM, Doug Nelson <doug.nel...@nelsonmultimedia.com > <mailto:doug.nel...@nelsonmultimedia.com>> wrote: > > > > I appear to have fireblight popping up in my orchard. The ipm group tells me > to prune all limbs back to central leader and not to do any spraying. > > > > What do you do? > > _______________________________________________ > apple-crop mailing list > apple-crop@virtualorchard.com <mailto:apple-crop@virtualorchard.com> > http://virtualorchard.net/mailman/listinfo/apple-crop > <http://virtualorchard.net/mailman/listinfo/apple-crop> > > > Win Cowgill > > Apple-Crop Co-Founder > > Professor Emeritus, Rutgers, the State University > > Visiting Scholar, UMASS-Amherst > > CEO- Win Enterprises International, LLC > > Editor Horticultural News > > PO Box 143 > > Baptistown, NJ 08803 > > Office 908-489-1476 > > Fax- 908-996-6404 > > Email: wincowg...@mac.com <mailto:wincowg...@mac.com> > www.wincowgill.com <http://www.wincowgill.com/> > www.virtualorchard.net/ <http://www.virtualorchard.net/> > http://giselacherry.com/ <http://giselacherry.com/> > > http://virtualorchard.net/njfruitfocus/index.html > <http://virtualorchard.net/njfruitfocus/index.html> > http://www.appletesters.net <http://www.appletesters.net/> > http://nc140.org <http://nc140.org/> > Twitter @mrsuncrisp <https://twitter.com/mrsuncrisp> > > > _______________________________________________ > apple-crop mailing list > apple-crop@virtualorchard.com <mailto:apple-crop@virtualorchard.com> > http://virtualorchard.net/mailman/listinfo/apple-crop > <http://virtualorchard.net/mailman/listinfo/apple-crop>_______________________________________________ > apple-crop mailing list > apple-crop@virtualorchard.com <mailto:apple-crop@virtualorchard.com> > http://virtualorchard.net/mailman/listinfo/apple-crop > <http://virtualorchard.net/mailman/listinfo/apple-crop> > > > -- > Doug Nelson > President > Nelson Multimedia Inc. > _______________________________________________ > apple-crop mailing list > apple-crop@virtualorchard.com <mailto:apple-crop@virtualorchard.com> > http://virtualorchard.net/mailman/listinfo/apple-crop
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