Root Knot Nematodes

[Dragunov79]

Hello all, I have a question about Root Knot Nematodes. My garden was going good for about three years straight and then this past year all my tomatoes were doing very poorly. Their growth was stunted and they started wilting and did not produce. I was confused until I pulled one and saw the roots. Yep, Root Knot. UGH!! We have very sandy soil down here and I hear from everyone that Nematodes are really bad down here in South Florida. I was just wondering if anyone has any techniques they have used with success to control Nematodes. I don’t really have the funds to buy as many pots and supply’s that I would need to go the container gardening route. I’ve heard that a lot of compost and “green manure” will help, but only slightly. Has anyone tried any kind of control that has actually worked? Anything?
Also If anyone knows any good tomato varieties that are “resistant” to nematodes and where to get the seeds. I have only grown heirloom tomatoes so far and I’ve heard that these are the most susceptible to these critters. I don't like that I may be limited to only the few hybrid nematode resistant plants out there.

[b54red]

The best you can do is what you mentioned. I had good luck with fresh horse manure tilled in; but it takes large quantities and weeds will also be a problem. The only thing you can do that works fairly well is use good nematode rootstock and graft the heirlooms you want to grow onto those rootstock.

All my tomatoes this year were grafts done for fusarium resistance and I used several varieties that had no nematode resistance and now most of those plants are suffering with nematodes. The ones grafted onto nematode resistant rootstock are doing much better but even some of them are having limited issues with nematodes. The very dry weather we have been having for the past 6 weeks has definitely contributed to the problem lately. Most of the grafted plants I have had to remove had some degree of nematode damage but that is far preferable to dying of fusarium before ever producing any fruit. The rootstock that so far has done the best for me at resisting both nematodes and fusarium has been Multifort available from Paramount Seeds.

Bill

[efisakov]

In NJ we do not have it as bad. The only place I had problem was along the house. The basement walls keep the temperatures wormer and the Root Knot Nematodes were surviving even harsh winter.
I tried boiling water and pouring it over the infected area. The small spot that was infected got better. I used that area to grow herbs (dill, cilantro...), so they get replanted few times. I saw improvement right away.

[Cheryl2017]

I spray with beneficial nematodes every February and does seem to keep it bay, plus add as much compost as I can

[ginger2778]

Dragunov, here is a way to make your own self watering containers using 2 -5gallon buckets, and you can get free food grade buckets from bakeries such as Publix. They get them with their frostings and flours. Then all you need will be a drill to mahe holes, a plastic solo cup or similar, a piece of PVC pipe to get wapter down to the lower bucket, and your potting mix.
http://www.globalbuckets.org

[b54red]

After 40 years of dealing with nematode damage and trying everything, the easiest thing is to learn to graft and that isn't always so easy. Don't do like I did for 35 years, spending inordinate amounts of money and effort in a vain fight. This is nematode country and even if you drive them away somewhat for a short time they will return. Unless you are going to limit yourself to just a few plants then container gardening is also expensive and requires a good deal of effort every year.

Bill

[Barb_FL]

I planted a couple of nematode resistantant tomato plants (Anahu and Kewalo) in the ground and didn't see any difference in their roots when I yanked them up.
(even with the marigolds mentioned below). Maybe the marigolds need to be planted for months before.

I planted one of the resistant tomato plants in a raised bed and I have never seen such bad Nematode roots; they were up to the base of the plant.

No tomatoes on any of them by the time I yanked them.

I tried this too:

http://parkseed.com/golden-guardian-...p/01308-PK-P1/

in a raised bed and just in the ground. They really took off and got huge, dropped some flowers and kept perpetuating themselves. I don't know if they helped at all with the nematodes, but the ones in the raised bed seemed to help a lot with white flies on pepper plants. After awhile they also got huge and I felt like they were competing with the peppers for the nutrients; so I yanked them too.

Back to just containers and mainly earthboxes for me.

[b54red]

Nematodes eventually bother most of my plants, even the resistant ones. I have found that some nematode resistant varieties are much more resistant than others so you have to find the variety that works for you. I could not grow Kewalo here either. I never got a fruit from it though I planted it several times. If you are like me then you probably have the double problem of fusarium along with nematodes. I find the fusarium usually is the early culprit in poor production with nematodes affecting the plants more severely after a couple of months in the ground. Some of the rootstock I used this year have no nematode resistance but they still produced well for a good while because of the strong fusarium resistance before the nematode damage affected them too much.

Bill

[rick9748]

Use same marigolds. Cut back with hedge trimmers, let lay as mulch. Cut with lawn mower then till in. Must go in soil to have any impact.

[pocossin]

I have had some luck controlling nematodes in small raised beds (tires) by mixing wood ashes in the soil. I use a large shovel full per tire, maybe 1/2 square yard, and mixed it in well. I do this several months in advance of planting.

[b54red]

I will reiterate what I said earlier. I used fresh horse manure. I don't know what is in it that makes it so effective but the 3 years that I worked it in a few months before planting gave me nematode free beds. I mucked it straight from the stables and spread it about 2 to 3 inches thick over the entire bed and tilled it in immediately. When I planted my tomatoes in early March I had virtually no nematode problem where before they would infest almost every plant within about 3 months. I lost my supply of horse manure and after a few years the nematodes returned but not as bad. I tried cow manure and it helped a good bit but raised my phosphate levels way too high so I had to quit using it. I now have to depend on my own homemade compost which helps but is not as effective. Anything you can do to reduce the sandiness of your soil will help some because nematodes seem to love sandy soil. I used to be able to tell which plants had nematodes because they would be the first ones to have spider mites each year. In a normal year when spider mites are not terrible they seem to know which plants are weakened by nematodes and attack them first.

Bill

Originally Posted by pocossin

I have had some luck controlling nematodes in small raised beds (tires) by mixing wood ashes in the soil. I use a large shovel full per tire, maybe 1/2 square yard, and mixed it in well. I do this several months in advance of planting.

The potassium (and maybe the calcium, too) in the wood ash should help to make the roots a lot harder and more difficult to penetrate. I haven't dealt with nematodes (so, I don't know it's effectiveness there), but I have noticed how adding potassium sulfate to plants started indoors seriously makes the stems and roots a whole lot firmer/harder/tougher.

@b54red

That shouldn't surprise me about horse manure. I've heard great stuff about it.

[brownrexx]

I have no experience with RNN but I have read that adding a handful of crushed eggshells to the planting hole will help. It works by feeding beneficial, calcium loving nematodes which also feed on the damaging RNN.

I can't tell you if this works but it's easy to save eggshells, crush them up and add to the planting holes. I would try it if I had this problem.

[b54red]

I have pulled quite a few of my earlier tomato plants and all were grafted to one of the three following rootstock varieties RST-04-106-T, Estamino, and Multifort and none of them showed any nematode damage this year. I still have two full beds of tomatoes and it has been terribly dry the last month or so and I may have some damage in those beds but I won't know til I pull the plants in a month or two or if I'm lucky three. Even though grafting is a pain and can be very frustrating til you get the hang of it I highly recommend it for dealing with nematodes and fusarium wilt if you want to grow heirlooms.

Bill

You could always stabilize some hybrids with nematode tolerance and make sure you keep it in successive generations. Then there's always the idea of breeding landraces with nematode tolerance in mind.