Expert: Long Island Gardener - 10/24/2006

Question
Thanks for your quick and chatty answer. Can you give me any clue where to buy those chemicals? And what are the side effects, if any, that I have to worry about?
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The text above is a follow-up to ...

-----Question-----
I would very much like to get your opinion about what to do with red blotch in amaryllis. This has reached epidemic proporations. Practically all of the amaryllis I have and really a lot of different kinds.  Now almost all of them now have gotten red blocth.  I have tried dithane
NT. From what I can read so far, the book about amaryllis by S. Okenga recommends that you throw infected bulbs out.  I have a lot of these.  I hope you will have some good answers.
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Fire Blotch, Red Spot, Scorch, Red Blotch - scientists calls this fungus Stagnospora curtisii.

According to Penn State Cooperative Extension Service (www.cas.psu.edu/docs/CASDEPT/PLANT/EXTENSION/PLANT_DISEASE/narciss.html), best treatment is the finger-cooking Hot Water Bath given bulbs to cure various and sundry illnesses.

Symptoms: "Reddish-brown spots with yellow halos develop on leaf tips as they emerge. The spots enlarge, merge together, and the leaves die. Spots have small brown dots (fruiting structures) within them."  

This bulb disease is most likely spread by mites. Fortunately this is one problem I have only heard about so far.  Readers living in Florida, however, will find it on every corner.

Your question resembles a very similar one I noticed on Red Blotch a few days ago submitted by someone in Europe.  If I recall correctly, one bulb grower suggested she pay close attention to bulb quality and cleanliness to avoid contamination.  Systemic fungicides are never an option for me, but there are several that list Stagnospora as one of several Fungi problems they will cure.

The Starr Okenga volume is definite coffee-table level.  But you may find very useful another reference, "Hippeastrum: The Gardener's Amaryllis" by Veronica Read.

For the hot water bath, soak bulbs in water heated to 104 degrees F for 30 minutes, then dip in a fungicidal dip containing thiabendazole (Mertect-340-F) or thiophanate methyl (Cleary's 336, Fungo 50, Domain or Systex).  Let the bulbs air dry.  Then replant.

I really must find that posting to see who initially raised this question recently.  If I find it, I'll review the answers and send some along.

Answer
Thiabendazole (2-(1,3-thiazol-4-yl)-1H-benzoimidazole) is made by Merck as a fungicide/pesticide called Mintezol.  You can read the lovely side effects of this chemical, used widely in the fruit business including Chiquita bananas here: http://www.cdpr.ca.gov/docs/risk/rcd/thiabend.pdf#search='thiabendazole%20%24'.

Thiophanate-methyl is a strong chemical with side effects you don't want to experience first hand.

both are extensively used in the farming industry.  You would not have any trouble locating them at a farmstand that caters to farmers.

I wish I had an organic solution to this, but so far, there is very little to add in that area.  Good luck and thanks for writing.