Root knot nematode control

Anybody have any experience? I have some gnarly looking carrots and have seen knots on my tomato roots too.

The sands of North Florida are crazy with root knot nematodes.  There are no rocks, and hard roots are easy to eliminate.  Nonetheless, I cant grow a carrot with a section straight enough to julienne.  Bifurcated is not an adequate description of the things I pull out.

Earthworms in good abundance will do wonders for root knot nematodes.  I've had good results with the soil in one bed at my house in town after a season of promoting earthworms.  Carrots came out a bit straighter, and the turnips dis not have nearly as many blemishes below the soil line.

Part of the reason earthworms help out is the fact the root knot nematodes are tiny by comparison.  Earthworms eat whatever is in front of them, including nematodes, making them predators to some degree, albeit unintentional.  They also compete with foodstuffs within the soil.  It's not a complete solution, but will reduce the nematode population. 

http://idosi.org/aejaes/jaes6(5)/1.pdf

Does this mean massive amounts of chop and drop is the answer.

Ken,

How do I encourage enough earthworms? Are larger worms better?

Thanks!

to promote worms, give them what they need to thrive.  Lots of decomposed organic matter in the soil, leaf litter on the surface, constant water.

I was poking around EDIS, found this: Marigolds (Tagetes spp.) for Nematode Management

Marigold can suppress 14 genera of plant-parasitic nematodes, with lesion nematodes (Pratylenchus spp.) and root-knot nematodes (Meloidogyne spp.) the most affected (Suatmadji 1969).

Marigold roots release the chemical alpha-terthienyl, one of the most toxic naturally occurring compounds found to date (Gommers and Bakker, 1988). This compound is nematicidal, insecticidal, antiviral, and cytotoxic (Arnason et al., 1989; Marles et al., 1992).The presence of alpha-terthienyl inhibits the hatching of nematode eggs (Siddiqui and Alam, 1988).

This is worth a read.

Thanks Ken! It looks like marigold will make it into my spring cover crop mix.

We've had issues with root knot nematodes as well. Crop rotation helps. So do a cover crop of something like mustard (pacific gold). Once grown, work the cover crop into the soil. The chemicals in the mustard leaves will kill off the root knot nematodes. I've also some luck with beneficial nematodes but there's a higher cost associated and a protocol for applying them.

Is this the only thread on root knot nematodes? I really would like to hear more people's experience on this. RKN are said to be one of the worst pests globally causing decreased yields.

Somebody mentioned earthworms, I googled, and according to this new study they actually do not kill nematodes and actually spread them! What!
http://www.ag.auburn.edu/comm/news/2014/Nematodesmoveviaearthworms.php

Hi all's! I was stumped as to what could be preventing my industrial -grade vermiculture tea from getting my plants to fly out of the ground! It turned out the local nursery had a bacterial infection in their tomatoes, but that still did not explain the beets that looked like they were planted from the 6-pack yesterday and not three months ago or the watermelon that was 2 inches long after 3 months or what have you... I thought it could be the Napa Valley pesticide presents delivered at night from across the creek... gotta get on that pony and ride it still, but I pulled up the beets and whadda ya know! Root Knots!
I was searching Soil Ph and Nematodes and found some articles that clarify things this thread would Value.
Nematode Life Cycles
Soil fertility, Texture, and Ph
In a nutshell, potassium , the K of NPK, is the best cell wall strengthener and therefore the critical buffer element for Nematode penetrations. They spread like crazy in sandy soil but overwinter better in fine soil.
Solarisation is just raising temperature, not using wavelengths so it looks like a heat process, cooking soil, is the best method I see besides potassium, water and nutrients to ride the season. Nematodes practically are roots themselves by the adult phase of their life-cycle, since they can literally blow roots up by growing faster than roots can, there may turn out to be some wierd border of absorption that can be exploited to kill them, or, maybe they can be false-triggered into their life-cycle before planting and then starved, they often have 4 metamorphosis states...
I am thinking about using my tumbling composter plus a rocket stove to batch process my soil, I use macrobins that have a yard of soil in them each and I want the Nematode Nemesis done with! Sheez, if I hadda grow things to eat at all, I would have starved!

Peace.

we had a problem with root knot nematodes several years ago and I think the main thing that helped was 'chop and drop' leaving the roots in place and the decomposing matter discourages the nematodes. Not a problem at all since. the one soil test I had done did show we were low in potassium. I also quit bringing in any 'greenhouse' plants....so altogether, I guess, I couldn't say for absolute sure which didthe trick:)

“Insects and disease are the symptoms of a failing crop, not the cause of it. It’s not the overpowering invader we must fear but the weakened condition of the victim.”

-- William Albrecht

Going over the subject of high brix at a 420 grower forum that has many references to all kinds of gardening. When the nutrient content gets high enough, the only thing left
that needs doing is keeping the nutrients going... no pests or disease issues...

"There must be calcium carbonate, and other mineral forms of calcium. If you can find some field stripeing chalk, read the bag carefully. If it says, "Calcium carbonate, 90% (or better)" you're good here. There are rock dust products in your area, just search for them.

Soft rockphosphate isn't used in the mix for phosphorus....most of the P in SRP isn't available to the plant for months. It's a colloidal clay and has all kinds of calcium and trace minerals. The clay is also fantastic for CEC, which is very important.

Just do the best you can, with what you have, and think CALCIUM all the time. Find someone who grows absolutely mouth watering tomatos and find out what's in their soil. You're on the right track....just think very small rocks and calcium"

That's an example post from this discussion...Doc Buds Hi Brix...

I am not trying to get into hot water mentioning ganja with my first posts, but I, like a lot of other people would rather be working on a hot-rod than a beater, and it seems to me, that most
gardens aren't getting the 420 crowds fanaticism...

OK so 3-4 years ago I discovered I had RKN in a couple of small garden beds. They had been planted in carrots. The crop was a total loss; not only were they ugly they tasted nasty. I pulled up everyone, cut the greens off for the chickens and threw the roots in the trash, along with some weeds that were in there.  That fall I planted them with cilantro and giant red mustard. Both crops were picked, eaten and sold. In spring when they started to bolt I reversed the plantings and again, picked, ate and sold them. The next year I grew potatoes under a thick straw mulch and they were fine.

Unfortunately  before I discovered I had RKN I had put a lot of stuff into the compost piles which at that time were being worked by chickens in a new garden area. I was totally pumped to have 300 sq ft of new bed space to work with. I planted a lot in a rainbow of potatoes with drip irrigation and heavy straw mulch. One bed I planted in cabbage and one in favas. Raging disappointment! the potatoes had odd bumps, tasted nasty and rotted quickly, even in the fridge. Just as the favas bloomed they were totally covered in aphids and died. The cabbages weren't too bad, but small and lightweight.  Succession crops of sunflowers, tomatoes and other veg started off good, then looked like they weren't getting enough water. I was watering all the time (from this thread I've just learned that just grew more RKN!) I pulled up a couple of tomatoes and sunflowers up. Their roots were gnarly!

I pulled up every plant and stuffed it in trash bags, taking as much soil and roots with it as I could. I bought some neem based nematocide. I soaked each  hole where I'd pulled up a plant with it and experimented. One bed got broccoli and cauliflower, winter crops here. (RKN are not active in soil under 60 degrees). They did reasonably well. One bed got a mixed cover crop which included mustard, field peas, radish and other things. It did well until it warmed up in spring when it croaked. Some of the mustard did make seed tho so I knocked it all down to let the seed sprout.

The end of two beds are being overrun with bermuda grass which came in on some manure. The grass is lush and green. Nothing else has done too well this year, although I have had a good number of volunteer sunflowers and so far they look pretty good.

This fall I intend to plant more mustard, broccoli and cauliflower. This year I tried to get marigolds started but even they are not doing so good. Really considering putting chickens back in there for a year or two since they would eat every bit of green, which would hopefully starve out the RKN.

I did buy a micharizal innoculant (however you spell it!) and have been inoculating my seeds and transplants. I have been working to add minerals that my soil test indicates I need, but maybe I haven't put enough down in that garden yet. So that's where I"m at right now. I have lots of earthworms all over.

I have been hesitant to use the nematocide much, as I thought it would possibly kill other things and knock things more out of kilter, even tho it's OMRI certified. However, I do intend to drench any nursery stock I bring in in the future, before planting out. That should prevent getting them again from the outside- they aren't native here and that's the only way to get them. figure if I drench them and then hold them a few days or a week, then innoculate with the fungal innoculant things should go well.

One other garden space was so totally infested with RKN (apparently I was spreading it around in the compost) that I did just put chickens and some ducks in there. They have been on that piece almost a year now. Hopefully by the time I get them moved to a new spot the RKN will have died off for lack of food. That space is totally surrounded by hot dry, cementlike caliche so I don't think they could migrate anywhere else

There are fungi that trap nematodes. From https://microbewiki.kenyon.edu/index.php/Nematode_trapping_fungi#Varieties_of_Nematode_Trapping_Fungi.

Nematode trapping fungi, or “nematophageous fungi,” are carnivorous fungi that have developed methods and structures that enable them to successfully trap and consume nematodes. Nematode trapping fungi are responsible for keeping the nematode population in check and are an important part of the subsoil ecosystem. These fungi prey on nematodes and are in turn consumed by organisms on the next trophic level. Nematophageous fungi use several methods to hunt their prey. These methods include living within the nematode and slowly consuming them as well as spreading diseases through nematode populations. The fungi also live in the soil and set traps for the nematodes to squirm into.

It also has a picture, which is also used in the "Teaming with Microbes" book by Jeff Lowenfels and Wayne Lewis. More pictures can be found by Googling for "nematode trapping fungi".

I don't have a solution, but here's what I do on my own farm.i have root knot nematode in my soil.

..... Use resistant varieties if they are available.
..... Develop my own resistant landrace strains.
..... Till in a generous amount of homemade compost between each crop.
..... Don't let the crops get stressed by drying out.
..... Don't have bare soil surface, although I'm not sure if that makes a big difference with RKN. The idea is to keep the soil very friendly for an abundant growth of soil microbes.
..... Apply additional soil nutrients via manure and compost teas if warranted, to keep the crops growing lushly.