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Old 12-07-2003, 09:32 PM
Mark. Gooley
 
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Default Hydrogen peroxide for blackspot spores?

I saw some product sold as a sort of horticultural disinfectant,
with a mention that it could be sprayed on roses with black spot
as it would kill any live spores on contact. It turned out that it
was "hydrogen dioxide" at a concentration of 27% or so.

Now, as far as I know, that's a synonym for hydrogen peroxide,
and the drugstore stuff can be as cheap as $1 a quart for the usual
3% solution -- about a tenth as strong. So suppose that one put a
pint or quart of the cheap stuff for each gallon capacity of a sprayer,
and diluted it. Spraying it on any live black spot spores (and one
would hope, various other fungal spores, and perhaps some fungal
infestations) would kill them, presumably. Now, it's not a sure cure,
it's not a long-term preventive, but it's certainly cheap and it's certainly
not toxic. Anyone tried it? Any thoughts?

(After a couple rainy weeks last month, almost every rose I have has
shown SOME black spot, and some have nearly been defoliated. I've
been alternating Daconil and Funginex sprays on a weekly basis. Also,
some of the rugosae have something that looks like rust.)

Mark., north Florida, zone 8b




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Old 12-07-2003, 10:44 PM
Anne Lurie
 
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Default Hydrogen peroxide for blackspot spores?

Whoa, Mark, stop!

To the best of my knowledge, hydrogen peroxide is NOT synonymous with
hydrogen dioxide -- any more than carbon monoxide can be equated with
carbon dioxide!!!

Someone help me here with an explanation, it's been 40 years since I took
chemistry in high school!

Anne Lurie
Raleigh, NC



"Mark. Gooley" wrote in message
...
I saw some product sold as a sort of horticultural disinfectant,
with a mention that it could be sprayed on roses with black spot
as it would kill any live spores on contact. It turned out that it
was "hydrogen dioxide" at a concentration of 27% or so.

Now, as far as I know, that's a synonym for hydrogen peroxide,
and the drugstore stuff can be as cheap as $1 a quart for the usual
3% solution -- about a tenth as strong. So suppose that one put a
pint or quart of the cheap stuff for each gallon capacity of a sprayer,
and diluted it. Spraying it on any live black spot spores (and one
would hope, various other fungal spores, and perhaps some fungal
infestations) would kill them, presumably. Now, it's not a sure cure,
it's not a long-term preventive, but it's certainly cheap and it's

certainly
not toxic. Anyone tried it? Any thoughts?

(After a couple rainy weeks last month, almost every rose I have has
shown SOME black spot, and some have nearly been defoliated. I've
been alternating Daconil and Funginex sprays on a weekly basis. Also,
some of the rugosae have something that looks like rust.)

Mark., north Florida, zone 8b





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Old 12-07-2003, 11:08 PM
Anne Lurie
 
Posts: n/a
Default Hydrogen peroxide for blackspot spores?

Disregard my previous post -- apparently Mark was right, and I was wrong!
According to
http://www.omegachemistries.com/pdf%...20Dioxide.pdf, the two
are the same compound -- and Hydrogen Peroxide is a lot easier on the
skin, etc. if you spill it.

Just don't complain to us when all your roses starting looking like "blonde
floozies"

Anne Lurie
Raleigh, NC





"Mark. Gooley" wrote in message
...
I saw some product sold as a sort of horticultural disinfectant,
with a mention that it could be sprayed on roses with black spot
as it would kill any live spores on contact. It turned out that it
was "hydrogen dioxide" at a concentration of 27% or so.

Now, as far as I know, that's a synonym for hydrogen peroxide,
and the drugstore stuff can be as cheap as $1 a quart for the usual
3% solution -- about a tenth as strong. So suppose that one put a
pint or quart of the cheap stuff for each gallon capacity of a sprayer,
and diluted it. Spraying it on any live black spot spores (and one
would hope, various other fungal spores, and perhaps some fungal
infestations) would kill them, presumably. Now, it's not a sure cure,
it's not a long-term preventive, but it's certainly cheap and it's

certainly
not toxic. Anyone tried it? Any thoughts?

(After a couple rainy weeks last month, almost every rose I have has
shown SOME black spot, and some have nearly been defoliated. I've
been alternating Daconil and Funginex sprays on a weekly basis. Also,
some of the rugosae have something that looks like rust.)

Mark., north Florida, zone 8b





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Old 12-07-2003, 11:56 PM
Scopata Fuori
 
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Default Hydrogen peroxide for blackspot spores?


You beat me to it, pointing out the nomenclature.

However, the "horticultural disinfectant" is a 27% solution of hydrogen
per/dioxide, and there was no mention of that being diluted. I would be
remiss if I did not point out that diluting a 3% solution is not going to
*increase* the concentration to bring it up to anything near 27%...quite the
contrary. If it takes a 27% solution to kill spores, then 3% is just going
to annoy them.

I had not heard of using hydrogen peroxide as a spore killer, but it's worth
a try on a couple less prized specimens. I use Mancozeb (flowable manzate)
but if there is anything out there effective and less toxic, as well as
cheap, I am all for it.


Scopata Fuori


"Bad Cat!"



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Old 13-07-2003, 12:08 AM
Mark. Gooley
 
Posts: n/a
Default Hydrogen peroxide for blackspot spores?


"Scopata Fuori" wrote in message
...

You beat me to it, pointing out the nomenclature.

However, the "horticultural disinfectant" is a 27% solution of hydrogen
per/dioxide, and there was no mention of that being diluted. I would be
remiss if I did not point out that diluting a 3% solution is not going to
*increase* the concentration to bring it up to anything near 27%...quite

the
contrary. If it takes a 27% solution to kill spores, then 3% is just going
to annoy them.


Well, the instructions resulted in a dilution that would be under 3%
if memory serves. I'll go back and check the pages and see if that's really
so. Again, even if 1% or less suffices, it'd kill only the spores, but
given
the cheapness and low toxicity, spraying with dilute hydrogen peroxide might
be worth the trouble...or not.

I'll have another look.

Mark., zone 8b





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Old 13-07-2003, 12:08 AM
Scopata Fuori
 
Posts: n/a
Default Hydrogen peroxide for blackspot spores?


Well, the instructions resulted in a dilution that would be under 3%
if memory serves. I'll go back and check the pages and see if that's

really
so. Again, even if 1% or less suffices, it'd kill only the spores, but
given
the cheapness and low toxicity, spraying with dilute hydrogen peroxide

might
be worth the trouble...or not.

I'll have another look.


Please do! What was the name of the product? Perhaps there is some online
information. If common hydrogen peroxide is good for sporekilling missions,
I'll try it.


Scopata Fuori


"Bad Cat!"



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Old 13-07-2003, 12:32 AM
elfa
 
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Default Hydrogen peroxide for blackspot spores?

Don't know about your dioxide idea.

I'm in Zone 9, extremely dry summers. Absolutely no rain. We still get
blackspot. A local rose company says the following about blackspot:

"Black spot consists of black/brown spots on the foliage that can defoliate the
plant. Black spot spores over-winter until humid, wet spring/summer conditions
are favorable. In the winter after pruning, when roses are bare, gather up and
dispose of all the foliage from the ground. Spray copper or Neem in the spring
and lime sulfur in the winter. Baking soda works -- somewhat."

I used Need oil until I got Orthenex as a gift several weeks ago. But with Neem
oil, I had control of the disease and stopped it from spreading. You can buy
the concentrate and add several tablespoons per gallon of water for spraying.
That's if you want a non-chemical approach to using a chemical like Orthenex.
Apparently Neem oil is some extract from a tree located in India.

If you're still looking for a simple substitute from your kitchen, this is what
they say about powdery mildew (maybe it works for blackspot too):

"Powdery Mildew looks like a white dusting on rose leaves. It is controlled by
Orthenex. The organic method is 1T baking soda, 1T vinegar, 1 T vegetable oil to
a gallon of water. Other good sprays are neem oil, horticultural oils or ultra
fine oil (spray on cool days). "

elfa



In article , "Mark. says...

I saw some product sold as a sort of horticultural disinfectant,
with a mention that it could be sprayed on roses with black spot
as it would kill any live spores on contact. It turned out that it
was "hydrogen dioxide" at a concentration of 27% or so.

Now, as far as I know, that's a synonym for hydrogen peroxide,
and the drugstore stuff can be as cheap as $1 a quart for the usual
3% solution -- about a tenth as strong. So suppose that one put a
pint or quart of the cheap stuff for each gallon capacity of a sprayer,
and diluted it. Spraying it on any live black spot spores (and one
would hope, various other fungal spores, and perhaps some fungal
infestations) would kill them, presumably. Now, it's not a sure cure,
it's not a long-term preventive, but it's certainly cheap and it's certainly
not toxic. Anyone tried it? Any thoughts?

(After a couple rainy weeks last month, almost every rose I have has
shown SOME black spot, and some have nearly been defoliated. I've
been alternating Daconil and Funginex sprays on a weekly basis. Also,
some of the rugosae have something that looks like rust.)

Mark., north Florida, zone 8b




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Old 13-07-2003, 12:32 AM
Mark. Gooley
 
Posts: n/a
Default Hydrogen peroxide for blackspot spores?

I wrote:
I saw some product sold as a sort of horticultural disinfectant,
with a mention that it could be sprayed on roses with black spot
as it would kill any live spores on contact. It turned out that it
was "hydrogen dioxide" at a concentration of 27% or so.


See http://www.biosafesystems.com/labels...ec%20Label.pdf
for information on ZeroTol. It's labeled for black spot, 1:100
concentration for
the initial treatment if I'm reading the label right. Contact fungicide
only, of course.
That'd be more like 1:10 for store-bought cheap 3% peroxide.

I'm going to try it. I'll let you-all know what happens.

Mark., zone 8b



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Old 13-07-2003, 02:44 AM
Daniel Hanna
 
Posts: n/a
Default Hydrogen peroxide for blackspot spores?

In Scopata Fuori wrote:
I use Mancozeb (flowable manzate)
but if there is anything out there effective and less toxic, as well
as cheap, I am all for it.


Mancozeb works well, but my God it smells awful. I bet it works on deer
and Japanese beetles too :-)

The range of black spot remedies is getting pretty wide now, overall.
So far I know or have heard of:

* Triforine (systemic)
* Chlorathonil (contact)
* Myclobutanil (a new systemic, showing a lot of promise in Australian
and New Zealand tests)
* Bitertanol (contact - proprietary to Bayer)
* Baking soda mixtures (contact)
* Various oils (contact - I use Pest Oil but white oil and neem are OK)
* Milk spray (contact, works well at 1:5 parts water)
* Lime Sulphur (contact)
* Wettable sulphur (conntact)
* Mancozeb, Mancozeb Plus, Zineb (contact, sulphur based)

Did I miss any?

My favourites are triforine in wet weather, and milk sprays where it's
likely to be fine for several days. In 2004 Yates will be releasing
myclobutanil as a concentrate, and I plan to use that on my roses for
both BS and mildew.
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Old 13-07-2003, 02:56 AM
Daniel Hanna
 
Posts: n/a
Default Hydrogen peroxide for blackspot spores?

In m Anne Lurie wrote:
To the best of my knowledge, hydrogen peroxide is NOT synonymous with
hydrogen dioxide -- any more than carbon monoxide can be equated
with carbon dioxide!!!


Anne, you're right. Hydrogen dioxide is simply water - H20. Hydrogen
PERoxide is H202, i.e. one hydrogen per each oxygen atom. It
biodegrades to water plus oxygen quite easily.

If you want to know more, follow this boring link :-)
http://www.h2o2.com/intro/overview.html


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Old 13-07-2003, 03:32 AM
JimS.
 
Posts: n/a
Default Hydrogen peroxide for blackspot spores?

Wouldn't Hydrogen Dioxide be HO2, no? Cuz Carbon Dioxide is CO2, oui? So
water would be DiHydrogen Oxide.

JimS.
Seattle
where there's always plenty of H2O.



"Daniel Hanna" wrote in message
home.com.au...
In m Anne Lurie wrote:
To the best of my knowledge, hydrogen peroxide is NOT synonymous with
hydrogen dioxide -- any more than carbon monoxide can be equated
with carbon dioxide!!!


Anne, you're right. Hydrogen dioxide is simply water - H20. Hydrogen
PERoxide is H202, i.e. one hydrogen per each oxygen atom. It
biodegrades to water plus oxygen quite easily.

If you want to know more, follow this boring link :-)
http://www.h2o2.com/intro/overview.html



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Old 13-07-2003, 11:32 PM
Unique Too
 
Posts: n/a
Default Hydrogen peroxide for blackspot spores?

Daniel Hanna writes:

Did I miss any?


The *latest and greatest* of the organic ones, corn meal.

See the following links:
http://forums.gardenweb.com/forums/l...483014278.html
http://forums.gardenweb.com/forums/l...654396244.html

In fact, if you do a search for "corn meal" at the Garden Web main page, you'll
find 18 pages of links.

Does it work? I have no idea, but it is certainly less toxic, less damaging to
the plants than many other home brew concotions out there.

Julie
  #13   Report Post  
Old 14-07-2003, 06:32 PM
J. Del Col
 
Posts: n/a
Default Hydrogen peroxide for blackspot spores?

"Mark. Gooley" wrote in message ...
I saw some product sold as a sort of horticultural disinfectant,
with a mention that it could be sprayed on roses with black spot
as it would kill any live spores on contact. It turned out that it
was "hydrogen dioxide" at a concentration of 27% or so.

Now, as far as I know, that's a synonym for hydrogen peroxide,
and the drugstore stuff can be as cheap as $1 a quart for the usual
3% solution -- about a tenth as strong. So suppose that one put a
pint or quart of the cheap stuff for each gallon capacity of a sprayer,
and diluted it. Spraying it on any live black spot spores (and one
would hope, various other fungal spores, and perhaps some fungal
infestations) would kill them, presumably. Now, it's not a sure cure,
it's not a long-term preventive, but it's certainly cheap and it's certainly
not toxic. Anyone tried it? Any thoughts?

.......

Take care handling 27% H2O2; it can cause corneal burns if it
gets in the eyes. I'd use goggles and rubber gloves. It isn't
poisonous, but it -can- burn skin and mucous membranes.

Concentrated H2O2 is nasty stuff--a very strong oxidizer.

During WWII the Germans used 90% H2O2 for rocket fuel.


If the instructions really say to dilute to 1/10 strength, it may be
cheaper to use the drugstore stuff straight out of the bottle.

The breakdown products are water and oxygen, and it decomposes very
rapidly on
contact with organic material and certain metals, such as iron,
copper and silver.



J. Del Col
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Old 14-07-2003, 10:32 PM
Theo Asir
 
Posts: n/a
Default Hydrogen peroxide for blackspot spores?

The breakdown products are water and oxygen, and it decomposes very
rapidly on
contact with organic material and certain metals, such as iron,
copper and silver.


As those poor sods in the Kursk found out.

--
Theo in Zone 5
Kansas City


  #15   Report Post  
Old 14-07-2003, 10:42 PM
Theo Asir
 
Posts: n/a
Default Hydrogen peroxide for blackspot spores?


I second that. H2O2
is a fairly benign chemical but
very corrosive & explosive
in the right concentrations.

I would be real curious as to the
effect it has on foliage.

--
Theo in Zone 5
Kansas City

"Scopata Fuori" wrote in message
. ..

Well, the instructions resulted in a dilution that would be under 3%
if memory serves. I'll go back and check the pages and see if that's

really
so. Again, even if 1% or less suffices, it'd kill only the spores, but
given
the cheapness and low toxicity, spraying with dilute hydrogen peroxide

might
be worth the trouble...or not.

I'll have another look.


Please do! What was the name of the product? Perhaps there is some online
information. If common hydrogen peroxide is good for sporekilling

missions,
I'll try it.


Scopata Fuori


"Bad Cat!"







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