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Posted: Sun Jun 06, 2010 4:04 am
by navajo
The Helpful Gardener wrote:As it really heats up back off of the molasses as well; like half rate. That stuff can really boot the bacterial side up fast...

Will do. Thanks so much for the info and this GREAT site!


Posted: Wed Jun 09, 2010 1:52 pm
by garden5
Thanks HG. I think you're right because it seems to me that earlier in this thread one of the members posted about the plants looking a little sour after they dumped the dregs on the plants.

horticultural myth?

Posted: Wed Jun 09, 2010 5:32 pm
by rainbowgardener
So what do we think? Double Dog Farm recently posted a link to a collection of articles giving scientific consideration to various possible horticultural myths, here:

The terminology is a little misleading because not all of them are determined to be myths once she examines them, or only partly (eg myth: benefits of wood chip mulch, she ends up agreeing with Teaming with Microbes, that green mulches are better for annuals/ veggies but wood chip mulches are very beneficial to perennials, shrubs, trees).

But one of the myths she looks at here:

[url=]compost tea myth[/url]

she basically says there's no scientific evidence for benefits of ACT. HOWEVER, the only research she cites is re the ACT as disease preventative. She doesn't even consider claims for ACT as fertilizer/ nutritional additive, which I would have thought is the main point.

I went looking to see what I could find and immediately found this article on research done by Rodale Institute in conjunction with Penn state U

Summarized it says that ACT was effective treatment against powdery mildew in grapes, but not in pumpkins. In their potato patch there was not enough disease present to be able to show any results.


"The spuds did show a yield response to compost tea applications, however. Plants receiving regular doses of compost tea produced larger, better potatoes than both the nutrient-ingredient-only and the untreated control plants. Marketable yields in the compost tea plots were between 18 and 19 percent higher than in the untreated plots and about 15 percent higher than in the nutrient-only plots. Compost tea-treated plants also produced tubers that tested higher for a range of nutrients, including iron, boron, potassium, and manganese. Iron showed the biggest response, with levels an astonishing 1700 percent higher in plants receiving compost tea than in untreated plants."

To me that sounds HUGE. Especially in comparison to the nutrient only control group, where they worked on giving the plants all the same nutrients that the ACT would provide, without the ACT/compost. And still the ACT treated plants had 15% higher yield. So more, bigger, and more nutrient rich potatoes with ACT!

So what do you all that are using ACT think: are you using it primarily to prevent/treat mildew and other diseases or primarily for fertility/ nutrient benefits? What do you know of scientific evidence for the benefits of how you use ACT?


Posted: Thu Jun 10, 2010 2:21 am
by The Helpful Gardener
Increasing soil biology has been shown to be particularly beneficial to root veggies; no big suprise to me that they got that result for taters...

The Cornell study gets trotted out time and again to discredit ACT as a disease preventitive, but (despite my own opinion that the suppressive side of ACT has been overstated some) I have yet to see any qualitative assay of the tea used in that study. Sure we got a recipe for that one, but no assay.

Dr. Chalker-Scott's bias become obvious when she points to the E.coli contamination of spinach in direct comparison to ACT use (the sourcing of contamination was found not even to have been a component of the spinach production but run-off from an adjacent CAFO operation!).

I am not saying it is impossible that incorrect brewing could produce high coliform counts, but the nature of a biodiverse system is to increase biodiversity, not allow for dominance. And her reference to the EPA scientist decrying an array of "unknown microbes" speaks to the poor understanding of this concept among even seasoned professionals.

It is the very variety of organisms that is the true benefit of tea or compost, and maintaining aeration is all that is necessary to assure coliforms never become dominant. Competition, predation, and lack of ideal habitat make this virtually assured. These Dr.s need to spend some time with Dr. Ingham and get up to speed...

As for ACT as "treatment" I too find it to be mostly uneffective, but even Dr. Chalker-Scott concedes that it has benefit as a preventitive, despite her other objections...
There appears to be a trend for Nonaerated teas to reduce the incidence, but not the severity, of foliar diseases.
As my wise old granny used to say "an ounce of prevention is worth a pound of cure", but when you are focused on drugs, all you see is pills. And if you are supporting chemicals (that simply treat symptoms), why look at things that mean you don't ever have to use them?

I do not know Dr. Chalker-Scott's personal line of studies or opinions on organics but have already noted certain trends that seem biased almost to the point of disinformation. We must always remain cognizant that PhD's are people too, and just as prone to the vagaries of opinion (and tendency to support whoever is signing the checks) as anyone else. I would be very interested to see who is underwriting research this year at Pullyup...


Posted: Thu Jun 10, 2010 12:04 pm
by stella1751
Interesting post, Rainbow! I remember that when I began using compost tea last year, I had two baby squash plants that had stressed out after a hail storm. While their cronies grew and grew, those two babies just sat their and crinkled their leaves. After I used compost tea, they recovered. By the end of the summer, they were every bit as big and every bit as productive as the others.

I always credited TDB's corn meal for their recovery. I think I still will, despite evidence to the contrary :D

Posted: Thu Jun 10, 2010 1:31 pm
by Toil
I really have to agree with HG, but i want to point out that since getting a microscope I realize I have brewed many bad teas. The last batch was made from store-bought, and I saw the same 3-4 organisms over and over in high densities, and that was it.

Needless to say I chucked the tea.

So what's my point? I am floating the idea of communal you can use to look at samples and cultures. Seeing is believing. But where to do it? At a business? Library? Extension?

Posted: Thu Jun 10, 2010 3:24 pm
by garden5
Good point HG, it's always good to know who's financially supporting the studies and experimets that are done. That's not to say that all scientists contort data to make it benefit the underwriters, but it is interesting to know.

Posted: Fri Jun 11, 2010 2:39 am
by The Helpful Gardener
I truly don't know if the good doctor fallsinto that category or not; I have had other very good scientists entrench on an opinion without mercenary intent, including a science prof at Wesleyan who just could not see how I was getting nitrogen from bacteria to plants, despite being very smart and very friendly. Sometimes there are none so blind as those who will not see...

Ahh, toil, and there is the reason I question the Cornell findings. What did you brew and spray? Bad tea would make for bad findings... as for the tea, I hoped you chucked it on the compost pile; it all will sort out, and it is a shame to waste even the worst biology...

Stella, we were fooling with corn as I remember to feed Trichoderma fungus with it's notorious hunger for other fungi; who knows? It could well have been the case that it worked. Again, our diversity is our savior overall, but who knows which specific tools our plants will pick to defend themselves? Not us...


Posted: Sat Jun 12, 2010 2:46 pm
by garden5
Diversity really is the key with tea. I think that the more components we can get into our compost, while still keeping it balanced, the better tea we will brew up.

I'm also wondering something, if were better off brewing our teas (when using a fishtank pump) with milk jugs, should we still use the same amount of compost that we would with the 5 gal. (about 2 cups) or should we go with 1/5 of that amount?

Also, should we use just the aerator hose or would it be better to still hook it up to an air-stone.

Posted: Sun Jun 13, 2010 1:55 am
by The Helpful Gardener
It's more a matter of surface area than anything else; as long as you keep it aerated you are keeping it moving. We can blasty a lot of bubbles through something but the gas exchange still happens mostly at the surface.

The question isn't so much how much compost (just our inoculant) or how many airbubbles (just our engine of motivation) but how much surface area and how many times is that water being moved from the bottom to the top. Lots of tiny bubbles doesn't move what less larger bubbles do... still the increased surface area of many tiny bubbles is beneficial as well. This is why I always talk about a good mix of bubble size...


Posted: Sun Jun 13, 2010 4:35 pm
by garden5
OK, so you really can't go wrong as long as you have some good compost and an adequate amount of bubbles.

When you say "surface area," are you referring to the amount of tea that is exposed to air, as in a wide-mouth container versus a small-mouth one.

If that's the case, it sounds like it'd be better to brew 1 gal. of tea in a 5 gal bucket, which an opening diameter of about 18 in. or so rather than in a milk jug, which has a max opening of about 8 in. (if you cut the top off). In other words, a container with a top view of "O" is better than "o". Is this what you mean?

Thanks for the insights.

Posted: Sun Jun 13, 2010 4:47 pm
by The Helpful Gardener





Posted: Mon Jun 14, 2010 2:37 pm
by garden5
The Helpful Gardener wrote:Yes.




3 for 3...Woohoo :D.

Posted: Thu Jun 17, 2010 12:14 pm
by garden5
OK, I'm getting a brand new pump. Should I get the 10-30 gal. aquarium pump rather than the 30-60 gal. pump? They are those "whisper" brand pumps. I wonder if the more powerful one would end up being overkill since I'll only be making 1 gal. worth of tea at a time.

Which one do you think I should go with?

Thanks a lot.

Posted: Fri Jun 18, 2010 1:48 am
by The Helpful Gardener
I'm staying quiet for a bit: I want a groupthink on this one...



Posted: Fri Jun 18, 2010 1:51 pm
by garden5
The Helpful Gardener wrote:I'm staying quiet for a bit: I want a groupthink on this one...


Yeah, sorry, everyone, if I appeared to be excluding you. I'm actually interested in everyone's opinion with this subject.

Posted: Fri Jun 18, 2010 2:35 pm
by rainbowgardener
I think that is the trouble with letting a thread get as huge as this one. Personally I think it should be broken up and then some of the pieces locked. There's a ton of info in here, but it's not very accessible any more.

But there were big discussions of pump size on pages 16, 28, 30. Probably farther back than that too, I didn't keep looking....

Posted: Sat Jun 19, 2010 4:04 pm
by The Helpful Gardener
Good point RBG...

G5, here's my answer to your question you asked back in January...
A nice medium bubble has decent lift (for mixing) and still a nice surface area. The real trick is getting the bottom stuff to the surface; most of the gas exchange in any liquid happens there. Too fine a bubble makes for slow mixing... If you are making 5 gallons, anything that moves your water 3-4 times a minute would be great so think 15 to 20 gpm pump. A six inch airstone should do you; make sure to soak it in hydrogen peroxide with a little white vinegar between uses to keep the build-up and biological contaminants down...
And in February when you asked the same question again, Cynthia chided you to reread; she was right, too...

I know this is a behemoth but that is what the Search bar is for; it finds what you are looking for. It is always preferable to extending massive threads even further

To that end I am locking this thread down in it's current state. I encourage you all to start new threads around specific themes on ACT or direct extracts or whatever else you want to talk about; I look forward to those discussions.