Compost Teas: 24 hour, EM, IM, BD & fermented plant extracts

["Soil Foodweb, Inc." <info AT soilfoodweb.com>]

Hi Laura -

This happened to us last year in the SARE grant, when we were testing dose 
response.  That means, we were doing treatments that were: 12 gallons per 
acre of an ok
tea (we were getting only half the fungi we wanted), 8 gallons per acre of 
the tea, and 6 gallons per acre of the tea.

In the 6 gallons per acre treatment, about two months after the conventional 
people began having problem, the plot that was treated every 2 weeks came 
down with
serious mildew problems.  And I mean, bad mildew problem.  The mildew moved 
into the treatment that was getting tea once a week as well.

At this point, chemicals were necessary.  On your vines, if the mildew can't 
be controlled with an immediate tea drench of the vines, apply potassium 
bicarbonate
to suck the moisture out of the mildew.

Several companies sell this, Armicarb, for example from Helena Chemical Co, 
but several other compnaies sell their version of this, so ask your local 
Wilbur-Ellis
folks or Farm Services folks for their version - I don't know if one 
company's version is better than others.  Again, testing is needed.

But they all work on the same principle - osmotic shock.  I'm not sure the 
concentration needed, but something like 3% potassium bicarbonate in water 
should
work.  Although, directions on the container of the bicarbonate you buy would 
be more reliable than my memory.

Apply the potassium bicarbonate (carbonate probably would work too, as well 
as sodium bicarbonate except that is sodium you are applying to your vineyard 
then),
and wait three days to let the chemical do it's job of drying up the mildew.

I would apply the chemical out a good 100 feet from the area of infestation 
with mildew just to make sure you got the problem area.  If it's too 
difficult to
limit the application to a limited area, do the whole vineyard.

Three days after the chemical application, do another tea and resume the tea 
applications.  Scout the vineyard to make sure no other areas succumb to the 
disease.

There are two likely reasons for the outbreak.  First, inadequate fungal 
competitors got onto the leaves from the teas.  Most likely the teas you have 
been
applying weren't fungal enough.  Secondly, there may have been residues of 
chemicals (sulfur allowed by organic programs is a pesticide) in the vineyard 
and they
had to be dealt with by the biology you are applying before the biology can 
get established on the leaves.  Checking your leaves right after a spray is a 
good way
to establish that the organisms are surviving on the leaves.

We're doing the same three vineyards with the SARE grant this summer, and all 
three are doing just fine.  No mildew problems in these areas of these 
vineyards
even though the Willamette Valley is having a serious mildew year.  Not as 
bad as last year, understand, but serious.  Because all treatments are at the 
high
fungal dose, no outbreaks this year.  So far.

So, next year you will have an easier time of controlling the mildew, because 
you will start the tea two weeks before bud-break and have the protective 
biology on
the vines BEFORE the mildew spores arrive.

Please keep me posted on how it goes.  We need to have a central clearing 
house of how these things work, and SFI is glad to be that central 
information center.

Elaine Ingham
Soil Foodweb Inc.

>    Subject: [Compostteas] Re: powdery mildew
>
> I have sprayed my vineyard with CT since the beginning of the season. A few
> days ago we noticed some powdery mildew. Not alot but some.
>
> Any suggestions as to whether the tea should be more fungal or bacterial to
> protect the vines against pwodery ?
>
> Should there be a waiting period, and if so how long, prior to applying CT
> after using sulphur or Bordeau ?
>
> Laura Sabourin
> Feast of Fields Inc
> Demeter Certified Vineyard & Farm  http://www.ragdolls.net/vineyard.htm
> Ragenesque Ragdoll Cattery http://www.ragdolls.net/ragenesq.htm
> R R # 1
> St Catharines, Ontario L2R 6P7
>