Return to the Market Gardener Forum | Post a Follow-Up

 o
Root Knot Nematodes

Posted by eltejano SE Texas (My Page) on
Thu, Jun 17, 10 at 3:52

Nematodes broke-through the m1 gene in our resistant tomatoes this year. Also, soil temps got into the 80's well before harvest, thereby rendering the resistant gene ineffective. The tomato plots, which are drip irrigated and comprise 35 thousand sq ft, are so severely infested that we are either going to have to fumigate this fall or take that area out of production and clean fallow/solarize for several years. (The degree of infestation is beyond crop rotation or trap crop solutions).

Our project technical advisor has limited experience with nematicides like Vydate or Telone and is not comfortable with them. Methyl Bromide is no longer legal and Vapam is very expensive, difficult to obtain, dangerous to apply and often ineffective. The bottom line is that we simply don't have the expertise to safely work with these highly toxic chemicals.

According to the experts at TX A&M. LSU and U of Florida and our own review of the literature, there are no really effective organic nematicides that would work - especially in our coarse, sandy soil which has little organic matter. Solarization and clean fallow for several years appears to be our only solution.

Since nematodes are inactive at soil temps below 70 degrees, we are considering the following strategy as an
alternative and would welcome any comments:

(1) Remove and burn all tomato plants from infected areas when harvest ends in a few weeks. (2) Till deeply and clean fallow with glyphosate and/or solarize under plastic the rest of the summer. (3)When the soil temp drops below 70 in the fall and the nems are inactive, plant our winter greens in those areas and harvest them through spring until soil temps reach 70 again. (4) Till-in the crop residues and again clean fallow the infected plots all summer until fall. (5) Plant our tomatoes elsewhere and repeat this brassica/fallow rotation for several years until soil tests show that the RKN population has declined sufficiently.

We understand that brassica residues also help suppress RKN activity to some extent. If they have nothing to eat during their active months, we should starve them out...???

Thanking you in advance for your comments. We are a church-affiliated grower providing fresh vegetables to the public at no charge. We do accept donations from those who wish to contribute.

Jack Ellis
Gardeners for Jesus Ministry
Woodville, Texas


Follow-Up Postings:

 o
RE: Root Knot Nematodes

  • Posted by budb 8b (My Page) on
    Thu, Jun 17, 10 at 14:33

Jack
Frequent deep tillage can be effective if you have the
equipment and the horsepower. Try plowing under a thick
stand of Florida Broadleaf Mustard, 8 to 10 pounds
per acre, and till in as deep as you can when mustard is
about 6 inches tall. You probably have enough time to do
this two to three times this summer/fall and still get a
fall/winter crop in.
Solarization is a wasted effort. You can't get the soil
hot enough deep enough to have even minimal effect.
Try the mustard and deep tillage route. The worst that can
happen is an increase in your organic matter.

Good Luck!
Bud


 o
RE: Root Knot Nematodes

Hi Bud!

Thanks for the info. Despite spotty nematode damage, we're having a pretty good tomato harvest this year. We picked 600 pounds of Amelias yesterday and it's just getting started. We're running a double shift 6 days a week at the stand right now and we're raising some serious money for the youth mission trip. If we can't fumigate, though, the RKN will be devastating in that area next year.

Finally got the Florida Weave down pat. LOL I don't think I'm doing it like you (I don't carry a box of twine on my belt). You're probably faster, but it works - as you know, Amelia is a big plant with a heavy fruit load, and the three runs of baling twine and 3/8 rebar every two plants are supporting them okay.

We're still trying to get the technical and logistical support we need to fumigate the area - that's the only sure way to deal with it. Yesterday,at long last, we finally established a connection with someone at Dow Agroscience. Hopefully, Telone will be an option for us and, if so, they will provide the tech assistance we need to safely apply it. Bye, bye nematodes! (for a couple years LOL)

Jack


 o
RE: Root Knot Nematodes

consider another possibility. Use a DEEP mulch, 12 inches. This insulates the soil so the temp doesn't get as hot. Be sure to run your drip only when the sun is down, and wait an hour after dark before starting. You don't want the sun making the water hot and thus warming the soil.
I have had very good success with planting of other crops (not tomatoes) and keeping the water cool by running drip only in the cool hours after the sun is down is a big help.
Another benefit of mulch is it will help support other factors, both physical and biological, that work to inhibit nemas. Use a permanent mulch, don't turn it under, and let the soil build a good and proper soil structure of O, A, B, and C horizons.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Market Gardener Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here