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 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 From: apple-crop-boun...@virtualorchard.com [mailto:apple-crop-boun...@virtualorchard.com] On Behalf Of Hugh Thomas Sent: Thursday, July 19, 2018 1:14 AM To: Apple-crop discussion list Subject: Re: [apple-crop-2] What to do when fireblight hits tall spindle Doug, it's sort of complicated. First, you probably know the bacteria travels from the tip downwards. The idea is to cut well below where the infection has traveled. You can cut away some bark and see where the brown area meets green cambium. I cut pass this point - well past it. I'm guessing I would cut about three times the length of the affected area. For example, if the tip has died back 6 inches, I would remove 18 inches of that limb. This is my gut but but this has worked for me in the past. I don't know the extent of your knowledge, but you need to be careful not to spread the bacteria with your tools and hands. Some people dip their tools in alcohol or Clorox between cuts. I use Clorox wipes on my shears, making sure I use a fresh wipe almost every cut, as the wipe ought to be very wet. On small limbs, say a quarter of an inch or less, I rip the limb off. The big thing is, take action now!! With warm weather you can get a lot of damage. If you burn the limbs, don't let the smoke drift into your orchard - something a guy told me.... Sent from my iPhone 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 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://virtualorchard.net/njfruitfocus/index.html http://www.appletesters.net 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
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