Hi All,
  I recently purchased a small Fig tree on ebay and potted it up last night.  It had a fantastic root system, but I noticed just a few nodules on the roots that I suspect are Root Knot Nematode (RKN).  (I wasn't sure, because the few pictures of RKN I had seen before were for severe cases.)

  I'm searching around for possible treatments/cures, and I noticed that there isn't a whole lot on this forum on RKN.  So I figured I'd start a thread while I also looked around...

  I'm interested to hear if people have successfully treated and cured RKN on Figs.  I've seen references to people using Neem oil, Neem Cake, and some kind of heat treatments.  Others suggest making air layers or taking cuttings as the only solution (i.e. the tree is ultimately doomed.)  Others reported success with heavy mulching for in-ground trees.  My figs are in pots.

  Since it seemed to be a mild case, I don't suppose just cutting off the affected roots would work, would it?  (I'm probably bound to miss something, and the soil is probably infected.)

  Any links, references, ideas, anecdotes or thoughts would be appreciated.  We hear so much about FMV but not much about RKN, which somehow seems worse!!!

Jim

I have figs in the ground, we will see how they fare. I back filled about 5% crushed oyster shell in about 8 cubic ft of soil dug out. I also mulched heavily with oyster shell around the fig trees, so you see a nice white mulch around the fig.

Supposedly oyster shell helps at killing nematodes. Having a mostly sandy soil, I assume nematodes are already in it.

Bare-root, cut off infected roots, then soak in a 120F (I wouldn't go far past 125F but try to maintain 120F) bath for at least 10 minutes and up to 30 minutes, then repot.  For a small tree (thin roots) the shorter time should be fine.  For trees with thicker roots cut off thickest roots and/or soak longer.

I kept mine quarantined even though I treated them.  If you notice stunted growth during this growing season, air-layer the top and throw the roots away.  RKN in containers is a death sentence.  In the ground, not necessarily so.

Good luck.

A friend in Louisiana once told me of very good success using chitins.  http://www.agrisk.umn.edu/cache/arl02971.htm#manag

James --- In my brief searches before I posted this topic, I recall seeing you mention this heat treatment in passing...maybe on the GardenWeb forum a few years back.  Thanks for providing more detailed instructions.  Where did you find out about this?
  I just potted up two really nice plants with really great root systems into 3 gallon pots.  (I noticed the RKN on one, but the other likely has some, too. I guess it would be wise to discard all that potting medium after doing the treatment, huh?

Harvey -- That's an interesting link, and it contains info about more than just chitins  I'll need to go back and reread that.  I had also seen old postings about people mixing crab and shrimp shells into their soil...as a source of chitins.

Does anyone have any experience with other treatments...like Neem oil soil drenching, beneficial nematodes or anything else?

Thanks!
Jim

1/2 strength Hydrogen peroxide.

The late Hanc Mathies taught me to use the 3% Hydrogen Peroxide that you can buy over the counter.
Mix equal parts water to Hydrogen Peroxide and drench your potted plant with this. There are several benefits to using the peroxide. It kills the nematodes and other organisms and it provides oxygen to the roots. It will not kill your plant. It has worked for me.

I read an article many years ago about the limited spreading of Meloidogyne incognita (Southern Root Knot Nematodes) in Illinois due to the cold winter.  I had thought that putting bare rooted plants in the freezer might kill off M. incognita.  So I contacted the author of paper who was a professor and researcher at U. of Illinois (I can't remember his name or the which campus he was located).  Surprisingly, he call me back and we had a conversation about killing RKN.  He had indicated there was a better chance of killing M. incognita (as well as other RKN including M. hapla or Northern RKN) with heat rather than cold.  I did some more research and found that most plant material can handle 120F temps.  Also, that temp would be effective (probably at the low end) to kill off RKN and their eggs.  I'm *pretty* sure fig roots can handle hotter temps, but I'm not sure what the upper limit for temp/time is.  RKN's gestational period varies with ambient temps.  The warmer it is outside, the faster they procreate.  I've always heat treated during the winter months when there are fewer nematodes/eggs to contend with.

The soil, your tools, your hands, your clothes, etc. will be a potential carrier for RKN.  I bare-root any suspicious trees over a large burn pile in a ditch on the far side of the property.

Hi Leon,  How often should the hydrogen peroxide mix be applied?  My concern with this method is the uneven moisture levels in containers after watering.

Hanc told me that one application was all that was needed and I have never used it more than one time for the purpose of RKN treatment. I think it depends on the size of your container. I have never used it on anything bigger than a 1 to 2 gallon container. I would imagine you would need a lot of H2O2 if your containers were much larger than that. Perhaps soaking the root ball in a large vat of H2O2 solution rather than pouring it through the pot is also more effective and cheaper.