My initial post was done in haste and was not very tactful.
I have no interest in threatening anyone or in attempting to regulate
pesticide use. I only wanted to be certain that readers recognize
that home made remedies, while they may work, cannot be legally
applied as pesticides in commercial orchards. I'm not certain, but
I believe that EPA labeling is also required for chemical deer
repellents. However, so long as Mo's Guiness Stout is used only to
attract leprichauns and is not used directly as a deer repellent, we
can probably assume that it will be exempt from labeling requirements.
My comment about California in my earlier represented an
unfinished thought: Given the state budget situations and government
gridlock that seems to exist in both California and New York, both
states may soon be expelled from the union and forced to survive as
unstable and bankrupted 3rd world economies. Given that scenario,
pesticide regulations may be the least of our concerns.
Axel,
I didn't read it as Dr. Rosenberger threatening you,
merely explaining things. I learned something from his post.
People are interested in experimental results. But understand, this
list is geared toward commercial producers and researchers. That
means these folks are professionals. Although I'm not a serious
commercial grower myself (I sell a little fruit out my back door) I
can tell you most folks on this list are very experienced, read up
on the literature, and have been experimenting with blocks of
hundreds of apple trees. Researchers on this list many times have
multiple farms to use as an experimental base.. It doesn't mean
your research is irrelevant. Research on one tree may have
anecdotal value, and can lead to testing on a larger scale. But
keep in mind fireblight has been researched for many many decades.
I'm not trying to be unkind, but the truth is, it's likely your
methods have been tried many times before.
Mark Angermayer
KS
----- Original Message -----
From: <mailto:[email protected]>Axel Kratel
To: <mailto:[email protected]>Apple-Crop
Sent: Tuesday, July 14, 2009 1:36 PM
Subject: Re: Apple-Crop: Fireblight Update
Sorry, I meant to say use retromycin sulfate, which is perfectly
legal to use on plants, and even has the right EPA label, I just
used neosporin as a way to keep the powder on the cuts. I thought
neosporin had bactrin in it, apparently it doesn't. It would work
equally well with silicon paste or any other pasty substrate.
But anyway, I am truly sorry I ever even posted this. If someone
isn't even allowed to experiment and have someone on this list
threaten with Federal law, well, then so be it, given that this is
the second nasty E-mail I got, consider this to be my last post on
this list. You people take yourself way too seriously.
Good bye.
From: Dave Rosenberger <[email protected]>
To: [email protected]
Sent: Tuesday, July 14, 2009 10:24:09 AM
Subject: Re: Apple-Crop: Fireblight Update
I've enjoyed reading the postings and opinions concerning how to
manage fire blight in Alex's Ernst Bosch apple tree. Those of us
who have worked with or experienced fire blight know that this
disease is very difficult to understand and manage. What works on
one cultivar, in one year, or in one location may fail to work on
another cultivar/year/location and what is cost-effective for one
apple grower may be totally implausible in other economic models.
Thus, I'm not going to debate Alex's observations.
HOWEVER, I feel obligated to point out that within the boundaries of
the United States (and I believe that still includes California),
application of an antibiotic paste to pruning cuts is a violation of
federal law. Any product used in that manner would require a
federal pesticide label from EPA. That requirement applies to
homeowners and hobby farmers as well as commercial growers. So far
as I know, no antibiotic pastes are labeled for use on tree fruits
to control fire blight. There are good reasons for these
regulations, but I won't take time to discuss them. The bottom line
is that using human or veterinary antibiotics on fruit trees or
other crop plants is both illegal and potentially dangerous.
I posted a while back on an Ernst Bosch Apple tree that came down
with fireblight. I wanted to share with the group what had
happened, although I must say that after reading the latest
Illinois Fruits and Vegetable Crop news, I am grateful not to have
to deal with the fireblight outbreak that the Midwest is
experiencing this year.
We are not in a fireblight prone area due to our cool, dry
conditions, but this year, fireblight has broken out in a number of
local orchards thanks to a warm and humid, rainy and drizzly week
in May. So this has been a learning experience for me.
I finally figured out how to deal with the fireblight infection,
here is what I did:
Since only one of my 200 trees (of which 80 are apple trees on
MM111) came down with fireblight, my focus was to eliminate any
further disease vectors, so removal of the tree is the only
solution. However, I am a scientist by training, and my curiosity
got me to play with the tree for a bit to try to understand what is
going on.
Here are some of the observations:
Step one was to cut, but to my dismay, the infection returned,
even after several cuts. Disinfecting the shears seemed irrelevant.
The morning dew collecting on the cuts would often turn orange, and
the drops would carry the infection to lower limbs.
Step two was to try to figure out if the re-infection vector was
external, or the bacteria was already systemic in the cambium. So
for the next sets of cuts, my approach was to coat the cuts with a
oily antibiotic paste with a bactrin base (bactrin is a wide
spectrum antibiotic). The coating would prevent re-infection from
external sources, but not if the bacteria is systemic in the
cambium. Sure enough, another set of cuts lead to more infection,
the ooze coming from under the paste. It only took 24 hours for the
wood to turn orange under the paste, proof that the infection came
from inside the tree, not from external sources or from the pruning
sheers.
Step 3 was to prune back radically, past the node of the infected
branch. Upon close inspection, I discovered that the cambium had a
darker shade, Cutting into the darker shaded areas revealed healthy
wood, but the cut turned orange within 24 hours and would start to
ooze. However, cutting several inches below any slightly darkened
areas did not cause the wood to turn orange, and no re-infection
took place.
Step 4 was to douse the tree with antibiotic to make sure there is
not any residual fireblight bacteria on the tree. I used a
combination of bactrin and retromycin sulfate to treat the tree and
surrounding mulch.
At this point, it's safe to say the fireblight active infection is
gone, although I believe the bacteria is still in the tree, but
dormant for now even though there are no visible cankers. Since the
tree is so young, I plan on removing and replacing it after the
harvest this October. But before I do, I also plan on feeding the
tree some heavy nitrogen to get it to grow and see if the new
growth will show signs of re-infection.
My conclusion for controlling fireblight is the following: the
bacteria travels much, much further than 6-12 inches, and one must
cut past any infected ambium: Chances are trees could carry
fireblight even without showing any active signs of infection.
1) Always coat the cuts with an antibiotic oil-based paste to
prevent re-infection from outside vectors.
2) The wood must be placed into a plastic bag immediately and not
allowed to touch anything else. So it's a good idea to cover any
oozing branch into a plastic bag and break off the branch, then do
the pruning so no ooze droplet hits any other part of the tree.
3) Always disinfect the sheers in case the previous cut was into
still infected wood. Preferred disinfection is a field heat
treatement disinfector, which should be used anyway to prevent any
sort of disease spread. You wouldn't want the doctor not to
disinfect his surgical instruments before treating you, a plant is
no different.
4) Always observe for orange discoloration under the paste for the
next 24 to 72 hours. If the orange discoloration returns, the cut
was made into more infected tissue, and you have to cut further.
>
5) After any infected tissue is removed and discarded, the tree
needs to be treated externally with an antibiotic to remove any
residual bacteria.
I cannot vouch that the above would work outside of Santa Cruz
county; when I see the pictures of fireblight in the midwest, it
makes me wonder how one would even deal with fireblight once it
broke out, the only reasonable approach seems radical removal, and
preventative spraying in the Spring.
-- **************************************************************
Dave Rosenberger
Professor of Plant Pathology Office: 845-691-7231
Cornell University's Hudson Valley Lab Fax: 845-691-2719
P.O. Box 727, Highland, NY 12528 Cell: 845-594-3060
<http://www.nysaes.cornell.edu/pp/faculty/rosenberger/>http://www.nysaes.cornell.edu/pp/faculty/rosenberger/
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**************************************************************
Dave Rosenberger
Professor of Plant Pathology Office: 845-691-7231
Cornell University's Hudson Valley Lab Fax: 845-691-2719
P.O. Box 727, Highland, NY 12528 Cell: 845-594-3060
http://www.nysaes.cornell.edu/pp/faculty/rosenberger/
