Apples Apple scab No Michigan State University
Wine grapes Phomopsis No Cornell University
Downy mildew No
Black rot No
Potato leafhopper No
European red mite No
Wine grapes Powdery mildew Some Penn State
(greenhouse) Botrytis Some
Wine grapes Powdery mildew No Penn State
(field)
Turf grass Brown patch No Rutgers University
(An additional focus of published compost tea resear
ch is the discovery of human pathogens, such as
E.
coli
, in some ACTs. Though discussion of the topi
c is beyond the scope of this column, fecal
contamination of compost teas is a health issue of
serious concern to the EPA and other agencies.)
This represents the current state of university sci
ence behind the efficacy of aerated compost tea in
disease control. Will these results be published in th
e peer-reviewed scientific literature? One hopes so,
but the reality is that many scientists don’t publish “n
egative” results and instead move on to other more
promising areas of research. This is unfortunate
as the science behind compost tea is very young and
requires, as all researchers agree, substantial research
before the hypothesis of disease control can be
supported.
What do compost tea producers say about these negative r
esults? Often, there is criticism of tea microbial
content, the tea brewing process, the applicati
on process, weather conditions, other environmental
stresses, etc. – in other words, the fault is not w
ith the product. However, the overwhelming lack of
positive results in university ACT studies suggests that th
e hypothesis might be in error and need to be
revised. And even if the criticisms were justified,
then how realistic can such a technology be for the
typical home- or business owner who wants to make and apply their own compost tea?
This is the real problem I see in the world of com
post tea, which is the selling of a product whose use is
based on faith rather than science. As one proponent
states, “There is no doubt in my mind that compost
tea has already proven to be beneficial to agriculture.” Individuals with this mind-set are not open to
having their beliefs challenged by scientists or anyone
else. However, buying expensive “tea brewers”,
purchasing ready made “tea” at several dollars a ga
llon, or paying a company to apply ACT in the
absence of objective data sounds like
snake oil rather than science.
There are thousands of web sites with glowing anecdot
al praise for compost tea used as a foliar spray.
What seems to be missing are stories from the other side – from those business and home owners who
haven’t seen differences in disease control or have even
noted increased incidence and severity of disease.
In the interest of a fair and balanced discussion,
I am developing a web page for reporting these anecdotes
as they are submitted to me. Feel free to send them in – you can remain anonymous if you wish.
There is no scientific evidence for ACT di
sease control on turf or landscape materials
. Since ACT is not
registered by the EPA as a pesticide, it is illegal to
recommend its use as one, or to apply it as such to
another person’s landscape. Though some commercial s
ites disclose this regulatory fact, they also coyly
include anecdotal information extolling the disease-suppressing properties of their product. Laundering
product information to get around federal pesticide re
gulations is unethical. Misrepresentation of the
science behind compost tea represents, at best, landscape
management decisions based on faith rather than
science. At worst, it suggests corporate profits at
the expense of well-meaning but gullible consumers.
This bit....Disease suppression is irrelevant.
No one here is pouring up AACTs for disease suppression.
There's Neem amongst other things for that.
I only posted everything to keep the text whole.
Trying not to be subjective and give only parts that support what I'm saying.
But that's really irrelvant.
) but aside from that rare businessman, a farmer who reviews data and cost isn't inclined to run his compost through a spin cycle. He just adds the compost and does other necessary work.
