Re: [tomato] Organic preventative for Late Blight??
Lazaro E. P. Peres (Tomato@GlobalGarden.com)
Tue, 27 Apr 1999 21:41:55 -0300
I think that the ancient mix copper sulfate + calcium hydroxide could be
used. It protect the plant against many pathogens (fungus and bacteria) and
is a source of the macronutrients calcium and sulfur and of the
micronutrient copper. However, it will combat the fungus only if sprayed
before the infestation (its a protective fungicide).
Mix 10 g of CuSO4 (copper sulfate) with 7 g of Ca(OH)2 (calcium hydroxide)
and 1 liter of water. Adjust de pH to 6-7 (use indicator paper). If acid,
you can use more Ca(OH)2; if basic, use more CuSO4.
It has low toxicity and although it is really a mix of inorganic salts, I
think it could be considered a "organic" product.
Lazaro Peres
Sao Paulo - Brazil.
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> From: Greg Park <Park.Steel@worldnet.att.net>
> To: tomato newsgroup <tomato@GlobalGarden.com>
> Subject: [tomato] Organic preventative for Late Blight??
> Date: Segunda-feira, 26 de Abril de 1999 16:43
>
> Hi all,
>
> Well late blight struck this past weekend in So California. I had a 18"
> tall champion hybrid tomato plant doing quite nicely until early last
week.
> It had nice foliage and was a lush until I noticed some oily looking dark
> gray spots. I went looking for an organic fungicide and was given a neem
> oil spray by my local nursery. I sprayed the plant as per the
directions.
> Now this plant is planted at my work so I didn't see it over the weekend.
> When I left, the lower leaves were probably half covered by the blight,
but
> the top, newer foliage seemed unaffected. I gave it a nice good deep
> watering before leaving. The weather here during the weekend was
overcast,
> but no rain.
>
> Upon return to work today, most of the plant was burnt up. The main stem
is
> still green and the plant is not wilting.
>
> I'm starting to feel that it's impossible to grow tomatoes here without
the
> use of chemical fungicides...Does anyone know of a good organic fungicide
> that EFFECTIVELY combats early/late blight?
>
> Thanks and best regards,
>
> Greg Park
> Zone 10, Los Angeles, CA
> CEO-in-Training
> Park Steel Company, Inc.
> Park.Steel@worldnet.att.net