Nematocidal Mustard Cover Crop / biofumigant

Discussion in 'Plant Pests, Diseases and Weeds' started by Daniel W, Nov 1, 2022.

  1. Daniel W

    Daniel W In Flower

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    https://spudsmart.com/mustering-mustard-potato-productivity/

    Last year I planted Nemagon mustard in a small area, for a cover crop. The first test was to see if it would grow overwinter, as a green manure cover crop. It did.

    I planted it in mid December. I am zone 8a or 8b.

    By April, it had grown very dense, and was blooming in May. The mustard is most beneficial if you chop it and till it in while blooming. Later, I planted squashes there. I didn't expect a difference, and didn't see any. It's tomatoes, peppers, potatoes that I am most concerned about.

    I think there is good science behind using nematocidal mustards to reduce the nematode pest load. It's recommended as a cover crop on potato farms, to suppress potato early dying complex (PED). PED is mainly caused by the joint effects of Verticillium fungal pathogen species and root-lesion nematode species. (link)

    The whole article is very interesting. Rainy day reading. More from the link...

    "all the plants in the brassica family – such as canola, mustard, broccoli and cabbage – contain chemicals called glucosinolates. When the glucosinolates in the plant tissues break down in the soil, they are converted into gaseous compounds called isothiocyanates. Research has shown isothiocyanates are able to suppress or kill Verticillium fungi and root-lesion nematodes."

    But the Nemagon mustard was developed for higher levels of glucosinolates.

    More...

    "Mustards can also reduce various other soil-borne pathogens and insect pests through their isothiocyanate effect and/or through other brassica mechanisms, such as emitting compounds from their roots that suppress or kill such organisms"

    I figure, since my space is limited, I want to do everything I can to reduce soil-borne diseases and pests. This winter, most of my beds wont be in use for growing a crop. I usually mulch them with leaves. I decided, this year, I'll grow a cover crop of nemagon mustard and then chop it / till it in a week or two or three before planting my Spring crop. That will increase soil organic matter and, who knows? Maybe reduce soil borne diseases and pests? I want to think so, anyway. It's not exactly what the potato farmers are doing, but similar and maybe it will help keep the soil healthier.

    I will plant the mustard where, next year, there will be tomatoes and peppers. Maybe for potatoes too, although potatoes are planted much earlier.

    I wanted to grow nematocidal marigolds, but their prime growing season is the same as most garden crops, so it's more challenging. I still want to grow them separately and at least till them in where the schedule works out. I sort of did that with one bed already, but with French marigolds.

    Info from Canada
    https://www2.gnb.ca/content/dam/gnb/Departments/10/pdf/Agriculture/GrowingMustardBiofumigation.pdf

    Info from Australia.
    https://www.abc.net.au/gardening/how-to/nematodes/9429726

    I ordered a pound of seeds, online. They should be here in a week or two.
     
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  3. Pacnorwest

    Pacnorwest In Flower

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    Daniel very interesting.. I wish there was a plant to help decrease the moles, and voles populations.
    I don’t have nematodes . The moles and voles take care of that issue.
    I have read several articles that there are several veggie and deco plants that are resistant to nematodes.
     
  4. Dirtmechanic

    Dirtmechanic Young Pine

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    Because of the reproductive slowdown in nema due to temperatures falling, I could see planting late in zone 8, or just digging holes and carrying on. That nemagon mustard sounds great for a fallow year, which is hateful but rkn is so hard to be rid of since they are deep too. I have sprayed multiple times with nematicide after tilling and that helps, but its really just creating a window of time in which to bring in a crop. RKN is one reason I want to come out of the ground.
     
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  5. Melody Mc.

    Melody Mc. In Flower

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    This was an good read Daniel. Thanks for sharing that. The time line for full benefit is sure stringent. I had a friend who used to do something similiar with Buckwheat, but I don't think with the knowledge of the possible pest prevention.

    Interestingly enough, Mustard is recommended to be used as a trap crop for one of the pests I really struggled with this spring/early summer. The Lygus Bugs love it apparently, and if planted in a field and then carefully destroyed while full of lygus bugs, it can prevent an infestation in the garden. I was going to try a trap crop, but if I can fit it in my growing window, I may try some mulched in as well with my turnips ( my wire worm smorg)
     
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  6. Sjoerd

    Sjoerd Mighty Oak

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    Daniel, this is a subject of great interest to me. Not because of the effect on potato's per se, but rather my strawberry plants. I do want to read these, but being a technical bit of info, I may need to see this in Dutch, or just think hard about about the words. Some of the terms and abbreviations are not familiar. thanks for posting this.
     
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  7. Daniel W

    Daniel W In Flower

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    @Dirtmechanic, I don't blame you a bit. I have seen articles where people grew pretty big crops of tomatoes in large containers, on their driveway. I think in your climate, you would need drip irrigation, a reflective wrap, and a cardboard mulch for that. Which is what I do except mine are in raised beds so no reflective wrap. I suppose one could lay down some sheets of plastic and build a raised bed on top of that....

    @Melody Mc., I've used buckwheat as a green manure. I would have used it for chicken food but the deer ate all of it. You are right, I think. I am not aware buckwheat has insecticidal, fungicidal, or nematocidal properties. I'll have to look that up.

    @Sjoerd, I have not read it but possibly this paper is an option for you. You can request a copy from the author. It's 12 years old and no abstract was available, so who knows?

    https://www.researchgate.net/publication/46383441_Evaluation_of_biofumigation_in_the_Netherlands

    I think Chrome might have a translate function via google, where you can just pull up the article and it will translate it. Im not sure, because I haven't had Chrome for years.

    I sort of panicked because I poured used soil mix from a container that had potatoes growing in it, into the bed where I planted garlic. Only potatoes and beans did will in that mix. Then I thought, what if it contains nematodes? So I pulled out some other plants in the same medium and washed off the roots. No root gall that I could see. I hope it's OK. That was not the smartest thing I ever did. I'll be really angry with myself if I ruined that soil and garlic crop.
     
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  8. Daniel W

    Daniel W In Flower

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    That's interesting @Pacnorwest! I have LOTS of moles and voles. In fact, I collect mole hills to use for planting soul - it's finely ground and easy to work with. I didn't know they ate nematodes. Can we train them to eat slugs, too?
     
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  9. Daniel W

    Daniel W In Flower

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    @Dirtmechanic, I'm curious about whether nematode resistant varieties do better for you, or if nematode-resistant rootstocks have been successful. I looked into the rootstocks a little. They are pricey!

    Here, we have garden root destroyers called symphylans.

    https://extension.usu.edu/vegetableguide/leafy-greens/garden-centipede

    I don't know if they are in my soil. I hope that encouraging active soil populations of micro-predators will keep their numbers low.
     
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  10. Dirtmechanic

    Dirtmechanic Young Pine

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    Yes, but the key word is "Resistant".

    The buggers go too deep to dig, but thankfully even if they run their entire lives they only move a short distance. I can kill them left and right to a short depth, but to kill them deep takes time and rainfall and a consistent application of nematicide over winter. The life cycle slows, and they spend time in 3 phases.

    The problem is the in between times when they form about themselves what I consider to be a dragons eggshell. Nothing can get to them then. One has to wait for hatching, or the emergence of adults to have at them with awaiting controls.

    Heat cycles them up to emergence every 20 days in summer and down to once in 90 days across the cold months. Of course it is not a singular wave, so by beginning post season and being consistent across time the initial spring hatching can be greatly reduced.

    It becomes problematic to turn earth or even continue to spray for them once crops are planted though. You can create a window of time and especially for determinate plants this is even more than sufficient. Determinates suffer them again from mid season on into fall.

    It does not come to mind which indeterminates are resistant though I know a great many determinates are denoted as such. I suspect this spring time window has something to do with a resistant variety showing better production than determinates.

    This effort is how I can, without any government assistance, create a 20 dollar tomato. So the last efforts have been toward really large amounts of compost. I would rather have a tree hosted fungus than a soil borne needlenosed worm.
     
    Last edited: Nov 6, 2022
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  11. Daniel W

    Daniel W In Flower

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    :rofl:

    Sometimes I think I passed that price point a while ago. Now I'm trying to roll it back to something more affordable. Or at least avoid new costs, considering what's already spent as investment.

    I was reading about fungi that feast on nematodes, but I couldn't find a garden inoculum for that. My garden gets all sorts of mushrooms, especially in wet weather. Maybe there are nematodivorous fungi in there too.
     
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  12. Dirtmechanic

    Dirtmechanic Young Pine

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    Creatin (sp?) eating biodomes can be supported with compostable materials that themselves have creatin components. Oyster shell for example. Nema make their bodies of the same material. Turns out that shell is not that cheap either, relative to my location. This is the closest I have come to understanding a non seasonal long term bio fight against nema. Live organisms that are purchased are effectively seasonal themselves and that is one more expensive sort of hassle on top of all the usual hassles. I am not getting younger it turns out.
     

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