Is PT wood a fungicide?

My Foot Smells · July 1, 2015

I've noticed not as many mushrooms pop up in my PT wood beds. Have a variety of natural cedar, stone, and PT wood (CCA). Also have one plant on death bed with blight in cedar, but PT bed seems healthy - maybe coincidence?

Seems like fungicides are now copper based, which I've never used, only squirt with BT once a year if necessary.

I'm pretty much all natural, but do use PT wood to give long life to raised beds. I know there are a lot of purist that do not use PT and question affects; but research has shown very, very, very minimal leaching of the micro-anodized copper treatment with zero harm.

Tip of the day: Place a plastic flamingo in front of west facing tomatoes lower cluster to prevent sunscald.

Gardeneer · July 1, 2015

Bligh is an airborne disease.
What you are saying might be possible if the plants uptake something from that wood that kills blight spores !
But it sounds unlikely, to me.

Gardeneer

My Foot Smells · July 1, 2015

ACQ not the old CCA (which is not available)

I do not have any of the arsenic ones, just got senile.......

excerpt:

The compounds currently being used are alkaline copper quat (ACQ) and copper azole (CA-B). Both contain copper and a fungicide but no arsenic. The copper keeps insects at bay, and the fungicide prevents soil fungus from attacking the wood. In ACQ, the fungicide is quat, which is also used in swimming-pool chemicals and as a disinfectant. One of the brand names using ACQ is Preserve. The other compound, CA-B, uses copper and tebuconazole, a fungicide used on food crops. Brand names of this new pressure-treated wood include NatureWood, Wolmanized Outdoor, and Natural Select.

****

Gardeneer, maybe there is some evidence to suggest that impregnated copper in PT wood does act as a fungicide in some manner. IDK

My Foot Smells · July 1, 2015

Really don't know squat bout quat (which is the fungicide component in PT wood)

Gardeneer · July 1, 2015

MFS, I am not disputing your theory. But even fungicide ,directly applied on leaves, cannot destroy EB fungi completely. Obviously you cannot repel bacterial spores. All you fungicide does is to prevent them from multiplying. JMO

Gardenner

digsdirt · July 1, 2015

I think you answered your own question - "maybe coincidence"?

Sort of like the claim one sees that "putting TUMS in the planting hole cured my BER".

There are far too many variables involved to give the PT wood any credit for the differences. At best, and in theory only, it "might" reduce the soil's fungus growth within an inch or so of the wood itself by leaching. But for the plants themselves, it could also be just the wind direction, or the sun exposure, or the shape and amount of the plant's foliage since it is possible to have one plant with EB right next to another plant without any EB.

Some fungicides are copper based, many are not.

Dave

Mike723 · July 1, 2015

With all the alternatives to PT I personally wouldn't risk it with edibles.. I do use it, but only for my bamboo planters (don't eat the shoots). I would use a softwood like cedar or redwood. IMO things like didecyl dimethyl ammonium carbonate (DDA Carbonate -http://www.epa.gov/opp00001/chem_sea...6-Oct-04_a.pdf ) and monoethanolamine, have no business leaching into soils containing edibles...

While ACQ PT contains copper oxide, it certainly wouldn't do anything for the plants in terms of an external fungicide.. It's effective on the actual product (wood), and maybe an inch or so imparted into the soil via leaching (as Dave mentioned above). To assume the leached copper would be of any benefit to the plants, be it as a fungicide or even micronutrient would be highly speculative and wishful thinking at best. Deliberately applied copper based fungicides have a hard enough time controlling things like Septoria and EB. It would be a wonderful alternative to spray treatments, but as others have said, it just doesn't seem plausible to me.
A little snippet from finegardening.com:
"Even though the new pressure-treated woods are considered safe, Wolmanized Outdoor, according to its Web site, does not recommend using pressure-treated wood where the preservatives may become a component of food. Its recommendation is to use an impervious liner between the wood and the soil.
Consider using alternatives, such as decay-resistant wood like redwood or red cedar. Discuss with your lumber dealer whether its wood is heartwood, which lasts longer then sapwood from the same tree. If you are concerned about sustainable harvesting of wood, contact the Forest Stewardship Council (www.fsc.org). You may also want to consider another point: Pressure-treated wood does, in fact, last longer then untreated wood, so using it might mean fewer trees would be cut."

Welcome to the forums, hope to see more of ya! =)

July 1, 2015	#1
My Foot Smells Tomatovillian™ Join Date: Jun 2015 Location: Pulaski County, Arkansas Posts: 1,239	Is PT wood a fungicide? I've noticed not as many mushrooms pop up in my PT wood beds. Have a variety of natural cedar, stone, and PT wood (CCA). Also have one plant on death bed with blight in cedar, but PT bed seems healthy - maybe coincidence? Seems like fungicides are now copper based, which I've never used, only squirt with BT once a year if necessary. I'm pretty much all natural, but do use PT wood to give long life to raised beds. I know there are a lot of purist that do not use PT and question affects; but research has shown very, very, very minimal leaching of the micro-anodized copper treatment with zero harm. Tip of the day: Place a plastic flamingo in front of west facing tomatoes lower cluster to prevent sunscald.

July 1, 2015	#6
digsdirt Tomatovillian™ Join Date: Jun 2015 Location: No.Central Arkansas - 6b/7a Posts: 179	I think you answered your own question - "maybe coincidence"? Sort of like the claim one sees that "putting TUMS in the planting hole cured my BER". There are far too many variables involved to give the PT wood any credit for the differences. At best, and in theory only, it "might" reduce the soil's fungus growth within an inch or so of the wood itself by leaching. But for the plants themselves, it could also be just the wind direction, or the sun exposure, or the shape and amount of the plant's foliage since it is possible to have one plant with EB right next to another plant without any EB. Some fungicides are copper based, many are not. Dave __________________ Dave

July 1, 2015	#2
Gardeneer Tomatovillian™ Join Date: Feb 2015 Location: NC - zone 8a - heat zone 7 Posts: 4,916	Bligh is an airborne disease. What you are saying might be possible if the plants uptake something from that wood that kills blight spores ! But it sounds unlikely, to me. Gardeneer

July 1, 2015	#7
Mike723 Tomatovillian™ Join Date: Sep 2014 Location: CT Posts: 290	With all the alternatives to PT I personally wouldn't risk it with edibles.. I do use it, but only for my bamboo planters (don't eat the shoots). I would use a softwood like cedar or redwood. IMO things like didecyl dimethyl ammonium carbonate (DDA Carbonate -http://www.epa.gov/opp00001/chem_sea...6-Oct-04_a.pdf ) and monoethanolamine, have no business leaching into soils containing edibles... While ACQ PT contains copper oxide, it certainly wouldn't do anything for the plants in terms of an external fungicide.. It's effective on the actual product (wood), and maybe an inch or so imparted into the soil via leaching (as Dave mentioned above). To assume the leached copper would be of any benefit to the plants, be it as a fungicide or even micronutrient would be highly speculative and wishful thinking at best. Deliberately applied copper based fungicides have a hard enough time controlling things like Septoria and EB. It would be a wonderful alternative to spray treatments, but as others have said, it just doesn't seem plausible to me. A little snippet from finegardening.com: "Even though the new pressure-treated woods are considered safe, Wolmanized Outdoor, according to its Web site, does not recommend using pressure-treated wood where the preservatives may become a component of food. Its recommendation is to use an impervious liner between the wood and the soil. Consider using alternatives, such as decay-resistant wood like redwood or red cedar. Discuss with your lumber dealer whether its wood is heartwood, which lasts longer then sapwood from the same tree. If you are concerned about sustainable harvesting of wood, contact the Forest Stewardship Council (www.fsc.org). You may also want to consider another point: Pressure-treated wood does, in fact, last longer then untreated wood, so using it might mean fewer trees would be cut." Welcome to the forums, hope to see more of ya! =)