Two posts ago, I was describing the problem we have with
fungi in our coffee nurseries. We pretty much followed the path I described,
though there was a little more delay in getting the fungicide spray than I
expected. The garlic was crushed and applied the same next day and we figured
out after about two days that we could use a product called Nordox (Copper
Oxide) to try to solve our problem.
Here’s a rundown of how that process works:
Step 1: Check your own expertise for options of controlling
fungi organically. For me, when there is an actual problem, this kind of starts
and stops with stuff like garlic or papaya leaves. To be fair, a well run
healthy farm should be protected from fungi in a more preventative way (good
sun/shade balance, healthy/well-fed crops that can protect themselves, maybe a
compost tea spray, etc.) so when a fungus is obviously out of control as was
the case in our nursery, botanical methods kind of fall short. Philip and I
agreed quickly to reach for something stronger.
Step 2: Check the National Organic Program (the USDA’s list
of practices for organic production) for what synthetics are allowed. And I
quote:
205.601 Synthetic substances allowed for use in organic crop production.In accordance with restrictions specified in this section, the following synthetic substances may be used in organic crop production: Provided, That, use of such substances do not contribute to contamination of crops, soil, or water. Substances allowed by this section, except disinfectants and sanitizers in paragraph (a) and those substances in paragraphs (c), (j), (k), and (l) of this section, may only be used when the provisions set forth in §205.206(a) through (d) prove insufficient to prevent or control the target pest.(i) As plant disease control.(1) Aqueous potassium silicate (CAS #–1312–76–1)—the silica, used in the manufacture of potassium silicate, must be sourced from naturally occurring sand.(2) Coppers, fixed—copper hydroxide, copper oxide, copper oxychloride, includes products exempted from EPA tolerance, Provided, That, copper-based materials must be used in a manner that minimizes accumulation in the soil and shall not be used as herbicides.(3) Copper sulfate—Substance must be used in a manner that minimizes accumulation of copper in the soil.(4) Hydrated lime.(5) Hydrogen peroxide.(6) Lime sulfur.(7) Oils, horticultural, narrow range oils as dormant, suffocating, and summer oils.(8) Peracetic acid—for use to control fire blight bacteria.(9) Potassium bicarbonate.(10) Elemental sulfur.(11) Streptomycin, for fire blight control in apples and pears only.(12) Tetracycline, for fire blight control only and for use only until October 21, 2012.
Quite a list really. For the keen
reader, section 205.206 is basically what I described in Step 1 concerning the
mostly preventative best practices. In this case, myself and Philip are willing
to attest that they were insufficient.
Step 3: Figure out what you can get in
Cameroon. Procuring inputs tends to be a lot trickier here than in the US. I
don’t get a dozen catalogs sent to me each month like I did when I was working
in a greenhouse. For this, I sent an email to our friendly certifier asking if
he could point us in the right direction. He did, giving me the trade names of
available hydrogen peroxide and copper oxide.
Step 4: Apply, following all the same
safety precautions a person working on a conventional farm would. As you can
see in the picture to the left, we did. Now we wait the time prescribed by the
label to apply again (2 weeks).
I’m not happy that we had our nursery attacked by fungus (I
think it is botrytis, but who knows), obviously. At the same time, I am glad we
got the chance to go through this exercise. In the future, the decision to use
copper oxide fungicides will be more streamlined. As an Internal Control
System, we can put copper oxide on our list of allowable synthetic inputs and
permission to use it can come from me or Philip after we assess the situation.
Already, some farmers have asked us to use copper oxide to combat coffee berry
disease and we’ve denied them because it has never been shown to be very
effective and needs to be applied at a volume and frequency we’re not
comfortable with. To me, this means that the system works.
