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 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 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.
>>>
>>>
>>>
>>&g
