[Market-farming] Tomato disaster!

Paul Wiediger wiediger at windstream.net
Tue May 22 21:33:40 EDT 2012

Marlin,  Without being on site, it's difficult to make a definitive
analysis.  However, after growing tomatoes in high tunnels since 1995, I'm
going to say that you have some sort of fungal disease issue, whether
Sclerotium or Rhizoctonia, I don't know and both can exhibit the same
symptoms on plants, such as what you are witnessing.

There is no quick organic control.

Certain mustards and brassica cover crops, as well as mustard seed meal,
contain high concentrations of isothiocyanates (ITCs) - derived from the
degradation of glucosinolates (what gives them the pungent taste).  The seed
meal is also a significant source of nitrogen and other nutrients.  When
incorporated into the soil ITCs act as an effective biofumigant, reducing
populations of pathogenic fungal species (Sclerotium, Rhizoctonia, and
Phytium), nematodes, weeds, and certain insect species.  ( UT/TSU 2003)  The
mustards can be macerated and incorporated into the soil to serve as bio
fungicides, but I'm not sure that your forage mustards will have sufficient
isothiocyanates to be an effective.

I would suggest solarizing your high tunnel this summer by laying clear poly
over the soil area, sealing the edges and letting the heat from the sun
destroy the disease organisms.  Leaving the poly in place from July until
Labor day (a minimum of 4 weeks, but 6 weeks is better) will give you pretty
decent disease control (as well as annual weed seed control) down to 4
(research says 6) inches.

Good luck.  We understand what you are going through.

Paul Wiediger
Au Naturel Farm
Rocky Hill, Kentucky

--Original Message-----
From: market-farming-bounces at lists.ibiblio.org
[mailto:market-farming-bounces at lists.ibiblio.org] On Behalf Of Marlin
Sent: Saturday, May 19, 2012 8:23 PM
To: Market Farming
Subject: [Market-farming] Tomato disaster!

I am having what amounts to a major disaster in my high tunnel planted
tomatoes this spring!  I am having die off of plants transplanted three
weeks to a month ago.  Inspection of the roots reveals that about an inch of
stem below the soil line has begun rotting and collapsing causing sudden
death of the plant.  I would estimate that I have lost upwards of 1/3rd of
my plants in one house and it looks like I am going to lose more.  I posted
here one day last week and several responded that it is damping off.  The
damp off I am familiar with happens in the greenhouse soon after young
plants have come up.  I don't think you would see damp off of 18 inch to two
foot tall plants, some of which had tomatoes on approaching the size of golf
balls. I have heard of warnings about putting fertilizer too close to stems
at transplanting.  I had put about two tablespoons of "Plant Tone" (an all
organic product) mixed in the soil around the top of the roots at
transplanting.  I have done this for years and never had trouble.  Once
about 15 years ago I had a similar problem when I transplanted tomatoes
through plastic mulch into ground that had one foot tall red clover plowed
down about a week or two before.  I figured that that was triggered by too
much bacterial activity in the soil breaking down the clover and also
attacking the tomatoes.  The soil in one high tunnel had been amended,
tilled, and plastic mulched last fall and did not have an excess of freshly
decomposing organic matter in the root zone. The other high tunnel had not
been mulched and was planted to over wintered spinach last fall and it had
lettuce plugged into it in very early spring. I had seen about 5% die off of
lettuce soon after transplanting to some similar type of root rot but it was
nothing to be alarmed about. There is some tomato loss in that house but not
nearly as bad as in the plastic mulched one.

Now I am wondering what the heck is going on and what should I do about it!
I'm thinking of buying some replacement plants and soaking the roots in some
sort of fungicide before putting them back in the holes.  I would also spray
fungicide at the base of the plants that are still living.  I would rather
not use something chemical.  We do have an abundance of forage mustard
growing in other areas of the field which was planted for the purpose of
natural soil fumigation. Would it work to make up an infusion of it and
spray it on the soil?  I need to pick some brains here!

Marlin Burkholder
Shenandoah Valley

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