Friday, July 9, 2010

Three Week Results of Bioassays Performed on Manure Suspected of Damaging Local Gardens


*****BE SURE TO READ THE POST FROM THE FIVE WEEK RESULTS. THEY ARE VERY DIFFERENT FROM THE THREE WEEK RESULTS IN THIS POST*****

Damaged tomato plant in Asheville garden
  
Undamaged pepper plant in Asheville garden
  
Damaged pepper plant (where manure was used) in Asheville garden

In early June, some home gardeners in a neighborhood in Asheville had peppers and tomatoes that were very twisted and odd looking.  It looked very much like herbicide damage.  They asked around their neighborhood and no one reported using any herbicides, such as 2,4-D, so they tried to figure out what they had in common.  The common factor appeared to be manure they purchased from a local farmer.  The previous summer, a local organic farmer suspected he had plant damage from manure obtained from the same farm.  This was in the midst of all the reports of herbicide carryover (mostly aminopyralid and chlorypralid) in manure and compost.  However, when the farmer who supplied the manure grew plants directly in the manure pile (in 2009) they grew fine!  The manure provider, not wanting to cause damage to anyone's plants, made special efforts throughout the year to ensure herbicide-free manure in 2010.  In particular, all hay sources were questioned about herbicide use and bean bioassays were performed on the manure.  So, this farmer was frustrated and discouraged when the manure was again suspected of causing damage this year.

This is where I stepped in.  I asked that farmer to bring me some of the same manure that was being sold and some of the hay that was fed to the animals.  We set up our own bioassays, using small tomato transplants.  Tomatoes seem to be even more sensitive to the herbicides than bean and peas.  We grew plants in our standard potting mix (STD), in a 50:50 mix of manure and potting mix (COMP), in potting mix with hay on top (STRW) and we planned to use a manure tea, too, but we never did apply it.  So the (TEA) treatment in the photos is really just another control with standard potting mix.  Below are pictures of the results after three weeks of growth.

Planting Day
Top is with suspected hay and bottom with suspected manure

Both rows are in standard potting mix (controls)

Three Weeks Later
 
Grown with the suspected hay


Grown with suspected manure

The control, grown in standard potting mix

The manure and hay provided to us did not damage these plants after three weeks.  I assume the samples provided to us are representative of what the gardeners used. 

THIS IS WHAT I WROTE AT THE THREE WEEK TIME PERIOD:

So, if this is the same manure the gardeners used, we still do not know what has damaged the plants in the gardens!  Although some diseases and insect damage can cause distortion, the damage these gardeners experienced really does look like herbicide damage.  But where the herbicide came from is still a mystery.  We do not know if it was air-borne drift or if it is in the soil.  Some of the gardeners were going to do some of their own testing, but I don't have those results back yet. I'll keep you posted!

NOW GO READ THE POST AT FIVE WEEKS AFTER PLANTING. 
THE RESULTS ARE VERY DIFFERENT.

4 comments:

  1. You may want to hold on to these plants for a while. Our plants only exhibited curling of the leaves on new growth, and well after the three week initial period of being in the ground.

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  2. You might want to check the pH and nutritional level of the soil - don't have my text handy at the moment but if memory serves, the pepper sure looks like a nutrient issue. upstate farmer

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  3. I'm relieved that it seems composted alpaca manure is not the problem but hoping that the true issue is found and can be fixed. I'm very sorry some of the people I sold compost to have had problems. Believe me, I don't want any of that herbicide going into - much less coming out of - my alpacas!

    Starr
    Venezia Dream Farm

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  4. having the same problem here in Candler NC. Doesn't seem to affect plants until the get to a certain size though. Tomato plants throughout our property ,intentionally planted in different mediums all get it. With and without straw, in compost, in clay, in my potting medium. I can't help but wonder if its somehow in the rain or air. It has hurt my potatoes, some beans and peppers as well.

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