On trees that young, fireblight would have started out as blossom blight, usually on one or two limbs. Infected parts of those limbs usually wither at the tip, sometimes curling downward. Then it can spread to the entire tree. Tree mortality can occur in the same season with young trees, especially with high nitrogen rates, or sometimes early in the following season. There should have been some sign of initial infection. If you missed a strep spray during an infection event this would be a strong possibility. The sudden death of trees is usually indicative of fireblight, but if you had a wet season, root rots such as phytophthora can't be ruled out. You might be able to determine more by looking for yellow tissue on collar of the root when the tree is removed.
Regarding pruning out strikes on trees this young. I've made cuts and the tree lived, I've made cuts and the tree died. Thus the general lack of consensus regarding whether or not to cut. The answers given in previous posts are all relevant. Time of the season, age of trees, extent of damage, growth rate of trees are all factors. It works best if you have a few strikes on otherwise healthy trees and it's early in the season. Prompt removal of trees beyond hope is a good measure. The newest thing is painting cuts with a paste made from Actigard. The old school method for central leader trees involved taking a blow torch and heating the bark at the point of transition from infected to healthy tissue. Haven't tried either of these. Definitely control leaf hoppers as they will spread fireblight very quickly. The clustering of damaged trees may be indicative of this. Lastly, there have been reports of sporadic, sudden collapse of trees (I believe in VA and PA) that remain unexplained. As our industry adapts to increasing bacterial, fungal, and insect pressure, the performance of replant tolerant rootstocks will be critical to our profitability. Brian Heatherington Beech Creek Orchards LLC 2011 Georgia Highway 120 Tallapoosa GA 30176 br...@beechcreekorchards.com > On Jul 22, 2018, at 3:01 PM, John Bruguiere <j...@dickiebros.com> wrote: > > Doug, this damage is similar to what we are seeing in virginia, after 3-4 > years trees suddenly dying off, we had a couple of nights last winter @ -5 > degrees, my guess it's winter kill, look at bark around graft union, if you > see splitting, that may be the answer. > > John > >> On 7/20/2018 11:16 PM, Doug Nelson 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. >> <22297.jpeg> >> <22289.jpeg> >> <22291.jpeg> >> <22301.jpeg> >> >>> On Thu, Jul 19, 2018 at 7:45 AM Kari Peter <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 >>> >>> >>> >>> 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 >>> >>> 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" >>> <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> >>> 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 >>> 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 >>> >>> www.wincowgill.com >>> >>> www.virtualorchard.net/ >>> >>> http://giselacherry.com/ >>> >>> http://virtualorchard.net/njfruitfocus/index.html >>> >>> http://www.appletesters.net >>> >>> http://nc140.org >>> >>> Twitter @mrsuncrisp >>> >>> >>> >>> _______________________________________________ >>> apple-crop mailing list >>> apple-crop@virtualorchard.com >>> http://virtualorchard.net/mailman/listinfo/apple-crop >>> >>> _______________________________________________ >>> apple-crop mailing list >>> apple-crop@virtualorchard.com >>> http://virtualorchard.net/mailman/listinfo/apple-crop >> >> >> -- >> Doug Nelson >> President >> Nelson Multimedia Inc. >> >> >> _______________________________________________ >> apple-crop mailing list >> apple-crop@virtualorchard.com >> http://virtualorchard.net/mailman/listinfo/apple-crop > > _______________________________________________ > apple-crop mailing list > apple-crop@virtualorchard.com > http://virtualorchard.net/mailman/listinfo/apple-crop
_______________________________________________ apple-crop mailing list apple-crop@virtualorchard.com http://virtualorchard.net/mailman/listinfo/apple-crop
