Nemakill

[Ginger]

It has been interesting reading this thread. Oklahoma Gardening which is a show on PBS, hosted a gardener who had recently purchased fill dirt for his greenhouse garden beds only to find it was full of nematodes. His plan was to plant mustard, once grown to till it in, then to lay plastic over and heat it up. The process would take about a year but he is confident the nem population would be significantly reduced. Have you all heard of this? Does it in fact work to reduce the population in soil? If so, it sounds like a good way to handle them organically.

[Bill Meyer]

Hi Ginger,

Well to simplify, foliar nematodes reproduce in great numbers. A garden could have millions. The only way to get rid of them is to sterilize everything. There are two ways to do that, chemically and with heat. The chemicals that would do it with plants in place have been taken off the market, so forget that. The best no-plant soil fumigant has too. I'm not sure how good the replacement fumigants are.

As for heat, they are heat-sensitive and are killed at fairly low temperatures - maybe 120F or so. I think you could get high enough temps covering with black plastic if you get high temps in the summer where you are. Of course all plants would have to be removed, and if they have nematodes then they will spread them to wherever you move the plants to. Cleaning up a bed would only be effective for that bed. If the nematodes have spread to surrounding areas, though, they'll just move back in.

They come out on the leaves when they are wet and spread through water runoff and between plants whose leaves touch. They can easily be carried to other parts of the garden. You don't need many survivors to start the population up again the next year. Ten survivors overwintering can make millions again the next year, so keeping the numbers down is only a temporary yearly thing. Is it worth the trouble?

........Bill

[Ginger]

Thanks for the response Bill. I was mostly curious about the mustard plant. The gardener on the show said the fumes put off by the mustard plant material decaying in the soil (after the plants were tilled in) along with the heat would kill them. So I guess my question was more about the mustard plants than the heat. Have you heard that mustard plants will help? That was the first time I had heard about it. You are right about whether it is worth it or not though.

[Bill Meyer]

Well, if the heat alone is known to kill them, the question of whether the mustard does too is kinda redundant. I've never heard about mustard carryng any chemical that kills nematodes though. Farming is different from gardening in that you clean out the field each year. Since we're hosta fans nothing like that is useful.

The foliar nematodes we deal with are very good at what they do and very hard to eliminate. Even if you could find a secret underground bunker full of the old chemicals like Nemacur and totally eliminated them from the garden it wouldn't be a permanent answer. They probably are in the neighboring properties, and with so many people having them now, even some nurseries, sooner or later you'd bring them back in on new plants.

The big question this year is how many people have nematodes and how many have the bacteria that has very similar symptoms. Control would be different for each so we need to figure out what we have. I wouldn't recommend wasting a lot of money on nematode cures until you are sure it is nematodes and not bacteria. My feeling at this time is that there's a lot of that bacteria out there pretending to be nematodes.

.........Bill

[Bill Meyer]

I looked into the mustard (brassica) question and did find it mentioned in an article. From a 2012 article about nematodes in turf grass in Australia:

"The demise of many widely used nematicides in the last 20 years has generated interest in the development of less toxic products for nematode control. A plethora of claims about the efficacy of a wide range of "biological", "organic" or "non-toxic" products have been made in recent years, but unfortunately many of these claims are based on preliminary laboratory or glasshouses studies, or are not backed by objective scientific data.

"In some cases, there is evidence to suggest that a product may be useful, but until efficacy is proven on turfgrass, the data are published in peer-reviewed scientific journals and results are substantiated by independent experts, claims of efficacy must be treated with a degree of scepticism. Products in this category include entomogenous nematodes, extracts from plants (e.g. sesame, wintergreen and citrus oils, neem, brassica meal and mustard bran), derivatives from microorganisms (e.g. DiTera), products containing molasses and other organic materials, fungal products such as those based on Trichoderma, Paecilomyces and various nematode-trapping fungi, and chemicals such as furfural and Agri-Terra."

A couple other interesting points from the article:

"(Bayer recently announced it has stopped production of Nemacur, with enough product left in the market to last about a year). Despite many years of research by agrochemical companies, there are no potential replacements on the horizon."

"The Australian grains, sugar and horticultural industries have invested millions of dollars over the last 20 years in nematode research...."

http://www.asianturfgrass.com/turfinfo/ ... fgrass.pdf

[Bill Meyer]

Just to keep everybody aware, here's the label for Nemakill:

http://cru66.cahe.wsu.edu/~picol/pdf/WA/62413.pdf

With all the promotion this product is receiving from AHS officers, I see local societies are buying it and carrying the "low toxicity" nonsense along to their members as if they know anything about it. If you intend to mess with this stuff, please pay attention to the label which says:

"Wear safety goggles, mask, gloves, and boots when handling. Do not get in eyes or on clothing. Avoid contact with skin. Do not inhale dust or spray mist. Remove contaminated clothing and wash before reuse."

Very few consumer-oriented products require this kind of full-coverage protection to use, which indicates a fairly high toxicity level. Since this product is unregulated, there is no information on what happens if you get it in your eyes, in your lungs, on your skin, etc. Since the manufacturer volunteers to tell you to be careful, it would not be a good idea to be the guinea pig for researching what it does to the human body.

Ignoring safety warnings is foolish, and those promoting this product to gardeners do not anywhere mention any hazards or safety precautions as if it is as safe to use as Miracle Grow. These are the kind of precautions normally recommended on fairly hazardous and toxic pesticides, and it wouldn't be wise to ignore them.

Meanwhile, the ridiculous claims pile up about Nemakill. Not only is it claimed to also cure HVX, but now in an article by Sue Sickels for the Western New York Hosta Society, it seems it repels slugs and deer. I've never seen anything like this bizarre promotion of a totally unknown product by non-profit educational societies. It's sort of like anti-education.

http://media.wix.com/ugd/47ea61_f646580 ... 8eac9c.pdf

[Tigger]

My chemistry news feed recently had an article about a natural-occurring compound called nootkatone being used to both repel and control deer ticks and mosquitoes (cue scary Zika music). While it can be isolated from cedars (like the Nootka cypress) and from grapefruit skins, it would still be too expensive to produce by extraction, so they're working on fermentation processes to make it in large quantity.
http://www.chem.info/news/2016/04/how-c ... save-world

Anyway, my point here is that if something like nootka/grapefruit extract works against ticks and mosquitoes, it's not so far-fetched to think that the natural compounds in Nemakill can work against foliar nematodes.

(I haven't searched the deep literature—etymology journals?—but at least the wire reports say that nootkatone "appears to have a mode of action distinct from that of currently used pesticides.")

[Bill Meyer]

As you can see in the Australian article above, many things have been shown to have some nematicidal properties in the lab, but until effective products are developed from them they are just interesting curiosities. It will take a decade or more for an actual product to be developed and properly tested for environmental impact, toxicity, and effectiveness in the field. Then after it is used for a few years somebody will invariably start trying to get it banned.

Nemakill is just a concoction put together and sold to anybody who wants it. It seems to be just a collection of oils and fatty acids that just burn anything they come in contact with, including us apparently from the safety recommendations.

There isn't anything new there. Nothing about it suggests it can kill nematodes inside plants or in dormant buds. Apparently it is no different for practical purposes than bleach, and certainly no reason to think it's the "silver bullet" Mortko was describing it as. Any value it has as a contact kill would lie in using it before the nematodes get safely back into the plant. In your area the window for that is closing rapidly.

If there was any useful info from the Grewal study it should be made available now before it is too late to do any good this year. The study was completed a long time ago now. Obviously the big question is whether anything was tested on plants. The presentation at Hosta College from Mortko and Deutekom said it wasn't.

[Tigger]

Bill,
You are misrepresenting what Rob and Cindy presented at the winter forum, based on what Cindy told me.

The latest Hosta Journal, with a summary of the research, is at press if not already in the mail. Yes, we would have liked it sooner, but the lead grad student had a family emergency in China. This stuff happens with academic research.

As to the warning label on the bottle, I have asked Excel Ag for a SDS. To me (a chemist who sees a lot of this stuff), it looks to me like they went for the CYA approach and made the suggestion for the highest PPE (perhaps per their other products). Lazy, it would seem, but gee they don't want you to get strong soap solution in your eyes.

David

[Bill Meyer]

What is it specifically that I have wrong about the Hosta College presentation?

Mortko repeatedly used the term "silver bullet", a standard sales technique, to associate those words with Nemakill. He used the presentation to put in a clear plug for the product, even comparing it economically (but not accurately) to Pylon, after dismissing all the other products.

As to the question of whether the products were tested on plants, did they say it was? To be clear, by "tested on plants", I mean were the products applied to infected plants and those plants checked at intervals to see if the products killed the nematodes in the plants? As was done in the North Carolina study and Grewal's 2002 study. My understanding from what I heard was said is that the answer to that is "no", that they were not tested on plants and that the research is now completed.

[Tigger]

The correct answer is "Yes, it was tested on infected, overwintered, field-grown plants." And would I be pushing so hard if the answer was "it didn't do a damn bit of good?"

Since they didn't want to reveal the final results of the study at the winter forum before it was published in The Hosta Journal, I think they danced a bit, but if Rob called it a silver bullet, then take that for what it's worth.

[Bill Meyer]

The Hosta College presentation was put forth to those attending as a summary of the finished study, yet it seemed to those attending to have nothing that was not in the earlier summary. Mortko was asked specifically if the products were tested on plants and he gave strange vague answers that amounted to not. Then he launched into a heavy-handed sales pitch for Nemakill, again calling it 100% effective as per the study. He even told those attending how to get it - to go to ExcelAg and say they were AHS members.

Given that Mortko and Deutekom said in the earlier summary that it was tested on plants when it wasn't, and did not retract that, it wasn't surprising that they beat around the bush when asked directly at the presentation. I don't expect a more "accurate" summary this time. Not when they're clearly promoting and endorsing Nemakill in the AHS' name. Any idea when Grewal's report will be published/released? That's where we'll learn what really happened.

[Tigger]

If you can't manage to read between those lines, then you'll have to wait for your copy of The Hosta Journal.

[Bill Meyer]

OK, I get that you're sworn to secrecy. I know how they behave. The idea is lost on them that the study info belongs to those who paid for it, including three societies whose treasuries I did my share to help build. The AHS put up far less than half the funding, but they think they own the results. The Journal will show up here soon enough, with whatever "version" of the study and its results they wrote up this time. Given the last two versions of what was done, I doubt this will be any more accurate. They've certainly demonstrated they don't feel it's important to give an accurate report.

From what I heard of the HC presentation, dancing around is a pretty good description for it. They certainly didn't want to answer questions and weren't prepared to do so.

But if it includes any more nonsense about it "curing" HVX and repelling voles and deer, I reserve the right not to believe anything else in there.

[Chris_W]

I also was at the Hosta College presentation and was really taken aback by, in my opinion, what looked like a blatant sales pitch for Nemakill.

Not once was it stated that hostas known to be infected with nematodes were ever used in the study. Mortko said that dormant, bare root hostas were potted in potting soil and the soil was inoculated with "x" numbers of nematodes, then the different chemicals and household items were applied to the pots while the hostas were still dormant. He didn't start out saying there were hostas used until he was asked, and then said yes, those pots of soil we were talking about had dormant hostas in them. An exact timeframe wasn't mentioned as to how long after the nematodes were added to the pots then the chemicals applied, but the hostas were still dormant when the chemicals were added, so it didn't sound like it was very long and I doubt long enough to let the hostas actually catch those nematodes. Then the mortality rate mentioned seemed to be the mortality of nematodes in the soil, not in the hosta. Then the different items which had no nematodes left were touted as 100% effective and he made specific references to some other chemicals as only being partially effective so those were given a bad rep. I wonder, though, if even systemic insecticides with only partial kill rates would be more effective long term against nematodes than a topical oil??

One lady in attendance said that she used Nemakill last summer on her hostas, repeatedly, and the first time she used it she burned her hands and burned her lungs. She had to get thick gloves and a gas mask to continue using it. But here is the next catch - she said that prior to purchasing nemakill she had a bad nematode problem and destroyed 2200 hostas because of it. So last year she started 1900 new hostas that she regularly (as mentioned above she repeated it through the summer, I believe she said something like every 7 to 10 days) and at the end of the year she only had 10 plants showing nematodes. Cindy Deutkom got excited and asked the lady to send her a record of those results so they could add it to the study. I then spoke up and asked the lady how many of those 1900 hostas were known to have nematodes and she said none that she knew of. If that is a basis for the study then the result to me would seem to be that using nemakill at best did nothing and at worst added nematodes to 10 plants.

Then after the presentation was all done Cindy and Rob started handing out 8oz bottles of Nemakill! Looking around the room I was not the only one who's jaw dropped. This did not seem like a presentation, it was more like a sales pitch. Pylon, Zerotol, and even boiling water showed the same results in the study (one reference point of zerotol had nematodes but it was an aberration that should have been discarded or repeated yet wasn't) however Nemakill kept being touted as that silver bullet. Yes, that word was used a lot, and from what I saw there was nothing specifically mentioned that would show it was ever used on actual hostas known to actually have nematodes. Mortko DID say that those plants which were in those pots were later grown on, but that wouldn't really be part of what was being studied. That would just show that a hosta caught nematodes after the experiment was already done.

Honestly, from what I saw, it is my opinion that there is something fishy going on with the study. I don't think I was the only person of that opinion based on the looks on people's faces, or the other non-vocal reactions to the presentation.

Not sure if Bill mentioned this yet or not, but it was also a bit ironic that the only picture of a hosta shown at that talk which was supposedly showing symptoms of nematodes actually looked like a bacterial infection and did not look like a nematode infection...

[Bill Meyer]

The experiment you describe sounds like it was intended to see if using a preventative drench when the plants were dormant would keep the nematodes from getting into the plant. The nematodes have to climb the outside of the petioles to get into the leaves, so they wouldn't enter a dormant plant. If poured onto a potted dormant hosta, I don't know if any would move to the scales on the still-dormant buds. The ones hiding in the dormant buds are the real problem treating dormant plants, so killing ones loose in the potting soil would give a result that is questionable in its value.

So, add nematodes then drench with products. It makes sense to that point, but the whole reason for it would be to see if drenches prevent them getting in after the plant leafs out. If the plants weren't tested later, and only the potting soil was, then something is really wrong there. In Grewal's presentation last spring he said he had previously tested drenches in potting soil in the funnels shown earlier here. Grewal knows what he's doing, so Mortko would have either been confused or he made the whole thing up.

This whole thing has gotten so weird that I wonder what the heck it is. I've never seen anything like this around what is a pretty simple and basic group of experiments that aren't really any different from the ones Grewal has been doing for the last 15 years. Confusion, deception, sales pitches, secrecy - it truly is bizarre.

Science is pretty straightforward. Do the experiments and report the results. What is all this other nonsense? With the AHS officers and the Nemakill people hawking that stuff as a miracle cure-all, this doesn't even vaguely resemble a research project anymore. The study is "interpreted" by the people who are supposed to be reporting on it to fit an agenda to promote a hinky product that has no background of effectiveness in the real world.

Nematodes have been a problem in agriculture forever and research has been ongoing for a century. Hundreds of millions have been spent on finding ways to control them with little to show for it. Some seem to think that this little bunch of simple basic repeat experiments will find the answer that all those hundreds of other researchers overlooked. You're more likely to win the lottery every week for a year.

If Nemakill was a real product that showed such outstanding efficacy toward such a difficult problem, it would be a big deal in agriculture where nematodes do billions in damage worldwide. If it were that good, ExcelAg would be concentrating on marketing to the ag industry where the big money is, not focusing their marketing on little hosta nurseries and gardeners, with dishonest sales pitches like it cures HVX too. Even governments would be knocking at their door as nematode damage to crops impacts global food supply to such an extent that it has an effect on starvation in countries that can't grow enough food to feed their people.

The big question this year will be trying to figure out whether people who think they have nematodes actually have the bacteria that causes similar symptoms. They would require different treatments. I suppose once the AHS officers and the Nemakill people find out about that they'll be saying it cures bacterial problems too.

[Bill Meyer]

Well, the new Hosta Journal has been put up at the AHS website where members can view it now. It contains Mortko and Deutekom's summary of the final results of the big nematode study that they rounded up $50,000 for. Finally after waiting 3 years we get to see what all that money paid for. Finally, all the questions will be answered. Drum roll please.......

I'll spoil the suspense by going right to the big question - were there any tests done on plants to see if anything killed the nematodes in the plants? The answer is clearly "no". No tests were done. They only tested things in water, on pieces of leaves in petri dishes, and in potting soil. No tests on plants. Not one. So we now have an idea how to clean up infested potting soil, but no idea how to kill nematodes in plants. Not much of value in that unless using old potting soil from nematode-infested hostas is important to you.

As for the rest of the study results, which are summed up in slightly more than one page with no charts or other information, there is only the following described as "key findings":

1. Overwintering - Eggs don't overwinter outside plants. Adults and juveniles do in soil, between scales on dormant buds, and in dead leaves. All of this was previously known, so why this is a "key finding" escapes me. Mortko and Deutekom think it's a big deal though.

2. Migration - The nematodes go up the petioles into the leaves in the spring. Late in the season they get washed off by rain or stay in dead leaves. All this was previously known too, at least for those who read Grewal's 2006 study, which may not include Mortko and Deutekom.

Here's that 2006 study - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2586432/

3. Chemical Controls - Nothing new here. Just the same results from the earlier summary.

4. Conclusion - Basically the conclusion is "it's time to start the sales pitch for Nemakill". Nearly as much space is taken up by Nemakill promotion as is taken up by the summary of the final results of the hugely expensive study.

So there you have it. No tests were done to see if any products killed nematodes inside hostas. Money spent, study complete, and we know no more about killing nematodes in hostas then we did before. And we certainly don't know that Nemakill can kill nematodes in hostas because it was never tested on hostas. Also, we know that Mortko and Deutekom very much want you to buy Nemakill.

[Bill Meyer]

In a small separate section of the big final summary, Mortko and Deutekom in their sales pitch for Nemakill provide a truly bizarre cost comparison that greatly misrepresents the products. For Pylon, they say that a $450 pint (16oz.) of concentrate will make 12.5 gallons.

The reality is that on the Pylon label, which they apparently didn't bother to read, there are two mixing rates provided for foliar nematode control - for 5.2 and 10 ounces to 100 gallons of water. At the weaker strength, that 16oz bottle of Pylon makes 307.7 gallons. At the stronger strength it makes 160 gallons. Obviously, that's a little different than 12.5 gallons, so the cost per gallon of ready to use mix at the $450 per pint cost is $1.46 for the weaker strength and $2.81 for the stronger.

Pylon label - http://www.cdms.net/ldat/ld3LP018.pdf

For Nemakill, they say that an 8 ounce container at $25 will produce 12.5 gallons of ready to use mix at $2.00 per gallon.

Pylon is very effective at killing nematodes in plants, and Nemakill was never tested on plants. Pylon is meant to be sprayed on leaves, while Nemakill would only be useful as a soil drench, since it has no way to enter the plant. Nemakill was tested at one quart of mix per pot. Obviously a lot more product is used in soil drenches than in spraying leaves, so Pylon is by far the less expensive of the two products. Are Mortko and Deutekom that bad at math? Or is this a deliberate part of their sales pitch for Nemakill?

[Tigger]

Bill, I know for a fact they tested plants that they had infected with nematodes. They then treated with Nemakill in the spring, and at the end of the same season, the plants showed no signs of nematodes. I wouldn't have been trolling you along if I knew otherwise.

I will try to find out why this experiment was not included in the summary report. It may have been a matter of timing in getting the issue to print: as I noted before, the grad student (post-doc?) researcher was out of the country and they wanted to get better details from him rather than publish what was a too-brief summary of the key experiment in the preliminary report used (apparently) to prepare the article for THJ.

My copy of the final report is at home and I will provide details later.

David

[Bill Meyer]

David,

I'm sorry, but WTF?

Mortko is the one who got together with Grewal and put this study together, choosing the experiments back in 2012. This study is Mortko's "baby". The contract was signed before anybody other than a few AHS officers knew what was in there. The proposal described a drench test where products were applied to dormant infected hostas in pots, to try to prevent nematodes from entering the plants. No tests are described involving leafed out plants. Apparently the study which was scheduled to conclude in fall 2014 was extended to fall 2015 for some reason, but it is not clear if this involved extra funding.

Mortko and Deutekom gave three reports - one mid-study written report, one post-study verbal summation, and now this written post-study summary. The last two appeared maybe six months after the completion of the study. The last two post-study summaries of the results described no tests on plants, and did not provide any charts of results of tests on plants.

As one main purpose of the study to quote the proposal was "Develop a comprehensive integrated approach to manage foliar nematodes on hosta and other ornamentals for nurseries and home landscapes", it seems obvious that testing on plants (and not just hostas) would be the centerpiece of the research. We have three official reports from the person who arranged the study with Grewal, and somehow they forgot the most important part?

Obviously these "reports" are really just a thinly disguised sales pitch for Nemakill that don't really have anything to do with what they are supposed to be doing, but if there were tests on plants that made their pet product look good, why would they leave that out? And obviously too, if Nemakill was effective in preventative drench tests on hostas before they emerge, why did they wait until the hostas emerged to release their report/sales pitch? It's too late for pre-emergent treatments now, yet they still are pushing Nemakill, even telling people to spray it on leaves.

Why would they keep secret even now that this product they are so desperate to sell actually worked on plants? Does this make sense somehow? Or is the gag order still in place? This is like the Twilight Zone.