Re: [gardeners] Fungicides

Dan Dixon (gardeners@globalgarden.com)
Sat, 14 Apr 2001 11:53:03 -0500

From: "byron bromley" <byron.bromley@gsd-co.com>

> What I think I am fighting "Looks" like "Fly Spec Disease" on Hibiscus.
> Smaller spots, mostly on the leaf margins.

Hi Byron. I mistakenly assumed you had a fungus on the fruits. Depending on
how severe the fungus is and how big the plants are, you might just try
trimming off infected leaves, increasing air circulation with a fan or
something, spreading plants out, lowering humidity, etc...basically make it
hard on the fungus.

> Peppers are an in the house grown under lights.  On a small Chile group I am
> on, we were having a first ripe pod contest.
> 
> We selected a small fast maturing chile that could be grown in a 3 gal pot.
> var.  Ring of Fire..
> 
> Just something to do to fight Cabin Fever..

Sounds fun. Are you gonna eat the peppers, or just be the first one with
fruit? I'm guessing you want to eat them, but if you just want your plants
to survive and win, use whatever fungicide you want on it. If contest rules
permit, of course. :)

> Fungoil is just a RTU version..
> 
> Here is a little SOHK  label reading
> 
> First  Compare the labels in the disease list of Ortho v Bonide.
> 
> One difference on that label is "late blight"   it's on the Ortho label,
> Not on Bonide..  Why??

Now you've piqued my curiosity. I didn't have any Fungonil, but I found the
label on Bonide's site (http://www.bonideproducts.com/labels/879-881.pdf).
In fact it does list "blights" in general, and about 4 different late
blights in particular. As far as ingredients go, here's what it says:

ACTIVE INGREDIENT:
Chlorothalonil (tetrachloroisophthalonitrile) ... 29.6%
INERT INGREDIENTS: ...............................70.4%

This is identical to what's listed on my bottle of Daconil, so other than
the inert stuff (who knows what that is?), it's the same product.

> Peppers are not on any Daconil label.
> 
> Ortho reps haven't answered.
> 
> The Bonide rep said that I can use Daconil on pepper plants,  but NOT on
> pepper fruits..  Reason was not told..

Peppers aren't listed on Fungonil either. Maybe the pepper fruits absorb and
retain chlorothalonil, or contain a synergistic chemical that affects its
action...dunno. I'd be curious to know why, if you ever get an answer from
anyone. At any rate, if the Bonide rep says it's ok to use it on the
foliage, I personally would not hesitate to use it.

I looked on the web some more and found a Q&A page on Texas A&M's hort site.
(http://aggie-horticulture.tamu.edu/plantanswers/vegetables/pepper.html)
Question #8 reads as follows:

> Q. The foliage on my pepper plants developed spots or lesions and the leaves
> have dropped off.
>
> A. This could be a combination of three foliage diseases: Alternaria leaf
> spot, Cercospora leaf spot and bacterial leaf spot. In most cases, two or more
> of these occur simultaneously on the foliage. They can be controlled with
> foliar sprays using a combination of chlorothalanoil and Kocide or any other
> copper fungicide. Begin at the first sign of the disease and continue at 1- to
> 2- week intervals during the critical disease periods.

So obviously they think foliar use of chlorothalonil on peppers is ok, too.

Good luck with the contest.

Dan Dixon