NRKN ?

[AlittleSalt]

I have been researching more about Root Knot Nematodes. As many of you know, I'm having to deal with them here in our Texas soil. I have lost count on how many sites I've read. Most of the sites are from places like Texas and especially Florida. So I thought RKN is just a southern states problem for the most part. Until this morning.

I was looking up info about RKN and onions. The second site on the search is this one: http://vegetablemdonline.ppath.corne...otNematode.htm

I had no idea that folks up in New York have RKN problems too. What really caught my attention was this on the above site "it is able to survive the extreme low temperatures during winter." It meaning NRKN.

Well that that messes up my hopes of the RKN not being able to withstand severe cold temperatures. We do have cold winters every once in a while in this part of north central Texas. Single digit lows are far from being unheard of here.

[maxjohnson]

https://www.ncbi.nlm.nih.gov/pubmed/18678924
http://link.springer.com/article/10.1007/BF00382516

I found these studies shows that soil amended with chitin materials reduces the nematodes. This is supposedly because the organisms that feed on the chitin also eat the nematode eggs.

https://microbewiki.kenyon.edu/index...trapping_fungi
This articles talks about fungi trapping nematodes.

https://ediblesanmarcos.wordpress.co...knot-nematode/
According to article, cedar mulch can help because the process that breakdown the mulch brings in organism and fungi that can help control the nematodes. I am going "back to eden" garden method with lots of mulching, so my hope is it will do something to reduce their population over time.

The one heirloom tomato variety I see that produce most prolifically in my garden is Black Cherry, despite being susceptible of RKN. Maybe it doesn't mean anything, but it's the reason why it's my favorite tomato.

[Cole_Robbie]

I don't think egg shells have chitin? You would be better served to look for waste products from the processing of shrimp, crab, or lobster. Some insect husks will also have it, but unless you're sweeping up a massive amount of dead bugs, it would be hard to get much from insects.

[maxjohnson]

Will have to go with crab meal then.

[kurt]

Max Johnson also might be interested in this approach for nematode control.

https://lisalapaso.com/2010/02/25/ne...maceous-earth/

[carolyn137]

Originally Posted by AlittleSalt

I have been researching more about Root Knot Nematodes. As many of you know, I'm having to deal with them here in our Texas soil. I have lost count on how many sites I've read. Most of the sites are from places like Texas and especially Florida. So I thought RKN is just a southern states problem for the most part. Until this morning.

I was looking up info about RKN and onions. The second site on the search is this one: http://vegetablemdonline.ppath.corne...otNematode.htm

I had no idea that folks up in New York have RKN problems too. What really caught my attention was this on the above site "it is able to survive the extreme low temperatures during winter." It meaning NRKN.

Well that that messes up my hopes of the RKN not being able to withstand severe cold temperatures. We do have cold winters every once in a while in this part of north central Texas. Single digit lows are far from being unheard of here.

There are southern AND northern strains of RKN's, they are different species as I recall. Over the years I think I've only seen two instances of the N ones,and not in NYS. That Cornell writes about diseases does not say that they are common here,just b'c Cornell is in NYS, says the Cornell alumnus.

Occasionally the southern ones are here,imported on the roots of transplants sent from the south,but they don't last since they can't take the freezing soil temps.

Lots of suggestions have been made and from dealing with RKN issues with many folks many times,some of what has been suggested just plain do not work, such as specific marigolds to chitin to shrimp shells to ebon rye.,etc.

If you do a search here at Tville,you'll see that everything in this thread has been discussed here before..And that's b/c RKN's are very difficult to deal with as some of you know already .

Carolyn

[Worth1]

We need another ice age bad.
Worth

[4season]

Some mushrooms have chitin as part of the cell walls. http://www.idosi.org/abr/4(1)/2.pdf
Right at the start of the intro it says chitin is present in most fungi as the principal fibrillary polymer of the cell wall. A couple years back we had a damp month in summer and mushrooms were very abundant up in the mountains. I almost picked a bushel or two to run through the shredder to mix into the garden.

[AlittleSalt]

Thank you Carolyn, You give me hope that these southern RKN can freeze.

I wonder if they can live through a week of burning? (Edit, that was meant to be funny.)

I have looked all over this site for help with RKN, and seems like hundreds more. Sometimes, you have to make the answer yourself. - not try to find it.

[Gardeneer]

QUESTION :

Is there other plants /vegetables that are affected by RKN ?
I am asking to find out ahead tim if my soil has RKN.

[carolyn137]

Originally Posted by Gardeneer

QUESTION :

Is there other plants /vegetables that are affected by RKN ?
I am asking to find out ahead tim if my soil has RKN.

Robert just answered you but here's a link to a Google search which I think is more comprehensive on RKN's in home gardens as well as commercial fields.

https://www.google.com/search?q=root..._AUIBygA&dpr=1

Carolyn

[b54red]

Even down here very cold weather can help with nematodes; at least for a year or so. Three years ago we had a blisteringly cold winter with a few nights getting down to 12 degrees and the days only getting into the low 20s and this lasted for quite a while. I almost lost my Satsuma tree that was protected on two sides by the house with only southern exposure and under a hoop house. More than half the tree was killed despite my precautions and the next year it had to grow back from just the main trunk so no fruit that year. My raised beds froze solid during the two cold weeks we endured and I lost almost everything that was growing under my hoops but the upside is the nematodes were greatly reduced. The following winter also had extensive cold but not quite as bad nor as long so that last year the nematodes were hardly a problem. Of course then we had last winter where it barely got blow freezing a few nights. The nematodes are still not back to full strength but if we have another mild winter I expect they will be.

The grafting has greatly reduced the RKN problem for me with tomatoes but they can still devastate cucumbers, okra, squash, and beans.

Bill

[AlittleSalt]

Gardeneer this is from http://www.lsuagcenter.com/NR/rdonly...todeLOWRES.pdf

"Although it is possible to starve root-knot

nematode and drastically reduce it after a year or

so, its host range includes most vegetables, grasses

or weeds that are found in the garden. This would

mean that you would have to keep it completely

free of any vegetation for an extended period. A

more practical approach is rotation and the use of

resistant or immune vegetables. Several vegetables

have been developed that have resistance against

the southern root-knot nematode, including tomatoes,

Southern peas, lima beans and hot peppers."

That's really just the tip of the iceberg on info about southern RKN.

[Gardeneer]

Originally Posted by AlittleSalt

Gardeneer this is from http://www.lsuagcenter.com/NR/rdonly...todeLOWRES.pdf

"Although it is possible to starve root-knot

nematode and drastically reduce it after a year or

so, its host range includes most vegetables, grasses

or weeds that are found in the garden. This would

mean that you would have to keep it completely

free of any vegetation for an extended period. A

more practical approach is rotation and the use of

resistant or immune vegetables. Several vegetables

have been developed that have resistance against

the southern root-knot nematode, including tomatoes,

Southern peas, lima beans and hot peppers."

That's really just the tip of the iceberg on info about southern RKN.

Thanks Robert.
At this point I am not trying to combat RKN ( Ihave nothing planted in my garden yet ) but rather to know if it present in my soil. So, for example can I pull a weed and see if it has RKN.

[Rajun Gardener]

Are you chitin me? If that's what works then you need to use worm castings and to make it better go with a no till garden and let the worms live in the beds. Make a worm casting tea and do some test this year. No chitin, I read it here

It seems chitinase will help destroy the eggs so you may need to start using it now to see a reduction by spring.

http://outoftheboxconstruction.com/h...-Repellent.pdf

A study using chitinase,
The number of hatched eggs was significantly decreased by KJA-424(Paenibacillus illinoisensis) inoculation compared to the control (Table 1), indicating the hatching inhibition effect. This might have resulted from the direct damage to the eggshells caused by the bacterial chitinase activity (Fig. 4, T1-T3). Mercer etal. [22] reported that the chitinase interferes with the egg hatching of M. hapla.
https://www.researchgate.net/publica...gyne_incognita


From Wikipedia: More specifically, several Paenibacillus species serve as efficient plant growth-promoting rhizobacteria (PGPR), which competitively colonize plant roots and can simultaneously act as biofertilizers and as antagonists (biopesticides) of recognized root pathogens, such as bacteria, fungi, and nematodes.

I would also try some: Mycorrhizae are symbiotic relationships that form between fungi and plants. The fungi colonize the root system of a host plant, providing increased water and nutrient absorption capabilities while the plant provides the fungus with carbohydrates formed from photosynthesis.