Potato nematodes

[marlingardener]

We plant Red LaSoda and Yukon Gold potatoes in sandy, well drained soil. Last year we had a small (perhaps 10% of the Yukons) problem with nematodes.
Can anyone tell me what to use, and when, to eradicate nematodes? We plant potatoes in mid-March and would like to use the least toxic remedy either before planting or at planting time.

 

[Chuck]

There really isn't anything that will instantly get rid of them. Crop rotation is very important, but the following link may be of help.
http://www.aces.edu/pubs/docs/A/ANR-0856/ANR-0856.pdf

 

[MaryMary]

@Chuck, in another recent thread you said tilling in the heat would kill them eventually, too. If marlingardener were to till and till after she harvests this year's potatoes, wouldn't that help for next year?

After posting on this thread I researched killing nematodes with tilling. Back 40 years ago it was common knowledge to till or plow numerous times during winter. Now the WWW says to till numerous times during the spring and summer when it is hot as heat and dryness kills them. So I guess the moral to this story is to till and till and till and till some more all year long. It did take 4 seasons to finally get rid of them all but the first year of plowing killed the majority of them.

https://www.gardening-forums.com/threads/those-damned-nematodes.13204/

 

[Chuck]

@Chuck, in another recent thread you said tilling in the heat would kill them eventually, too. If marlingardener were to till and till after she harvests this year's potatoes, wouldn't that help for next year?




https://www.gardening-forums.com/threads/those-damned-nematodes.13204/

The way I read marlingardeners post is that she wants something that works quickly and gets rid of them. Tilling does work but it takes a LOT of manual labor and time. Sure, numerous tillings now will help but changing the planting location will be a better result. Once nematodes are there they multiply quickly. She could also plant French Marigolds in a solid mass and then after flowering till the entire plants under, but she will lose at minimum a year, probably two. Then there is the fumigation method using chemicals I can't pronounce. There really is no easy or quick way but tilling many many times works

 

[MaryMary]

The way I read marlingardeners post is that she wants something that works quickly and gets rid of them.

Yes, I read it that way, but in the post, she said "least toxic," and you responded that there was nothing instant. I like to leave chemicals out of my garden, too, so I thought... if it's too late to solve it this year, maybe next year...

It sounded to me as if the soil were amended to be sandy, loose soil specifically for planting potatoes. (I could be wrong...) But I have a small spot I made that way for planting carrots. I understand that crop rotation is best, but that spot is for carrots!!


I like to ask questions. Partly because it might be another option for the OP, but also because the things I learn in this thread will be in my head when I need them!

 

[Chuck]

Yes, I read it that way, but in the post, she said "least toxic," and you responded that there was nothing instant. I like to leave chemicals out of my garden, too, so I thought... if it's too late to solve it this year, maybe next year...

It sounded to me as if the soil were amended to be sandy, loose soil specifically for planting potatoes. (I could be wrong...) But I have a small spot I made that way for planting carrots. I understand that crop rotation is best, but that spot is for carrots!!


I like to ask questions. Partly because it might be another option for the OP, but also because the things I learn in this thread will be in my head when I need them!

IIRC where marlingardener lives is blackland prairie soil. I know of no sandy soil anywhere close so I presume her soil is amended to grow potatoes. And when one grows the same thing in the same spot year after year you will probably end up with nematodes.

 

[DirtMechanic]

This is a contact killer, but nematodes run deep so that makes them hard to kill. And while they are in their egg they are evidently impervious to most chemistry so you end up making sure the chemistry is waiting for them to emerge which they do as temos rise. When it is really warm the hatching life cycle is 20 days, when cold 90 days. This product is mainly Thyme oil, and its recommended with another of there product called Zap, which is an iron + nutrient mix. Lots of humic material in both I believe. Read the kill sheet. Its impressive.

https://humagro.com/promax

 

[Chuck]

This is a contact killer, but nematodes run deep so that makes them hard to kill. And while they are in their egg they are evidently impervious to most chemistry so you end up making sure the chemistry is waiting for them to emerge which they do as temos rise. When it is really warm the hatching life cycle is 20 days, when cold 90 days. This product is mainly Thyme oil, and its recommended with another of there product called Zap, which is an iron + nutrient mix. Lots of humic material in both I believe. Read the kill sheet. Its impressive.

https://humagro.com/promax

I am glad to see this. And its organic too. I would like to learn more

 

[DirtMechanic]

I called them and got 5 gallons of each.

 

[Chuck]

I called them and got 5 gallons of each.

Is it expensive? And how much area will the 10 gallons cover?

 

[DirtMechanic]

1 gallon per acre diluted per spray treatment. I figure the amount I have will last a long time, Maybe 2 seasons. I mixed a cup [8oz] in my 2 gallon sprayer so its a midge strong. Tilling it in requires quite a bit more I expect. When I do that I will use a lot but I really do not have a handle on that amount yet. I am expecting to find a recommendation, but have not as of yet. So I am going to use the equivalent of 3 treatments when the weather warms and I do the first tilling. Then when I till for planting I will repeat. After that it will be top sprayed for the rest of the season as they indicate.

 

[marlingardener]

The soil was amended years ago to accommodate the pigs. It seems that sandy soil makes the pig's legs stronger and more muscular, so you get better hams. The former farmer must have brought in sand by the truck load!
Anyway, root crops grow great there, and it is a fairly large area, so I will rotate. However, I wanted to stop the nematodes before they take over.
We rototill the area twice a year--before planting and after the final harvest. Perhaps that has helped keep the little critters from spreading quickly.
DirtMechanic, I'll look into the solution you suggested. I certainly wouldn't need a gallon of each, but perhaps I can find another gardener to "go halvsies" with. Thank you!

 

[DirtMechanic]

It is sold in smaller containers, but I do not know where so I would just call them and they can direct you to the vendors in your area or supply it directly I bet.

 

[headfullofbees]

You could grow resistant varieties:

http://varieties.ahdb.org.uk/

 

[DirtMechanic]

Better they all die.

 

[headfullofbees]

Better they all die.

Then, for many pests, I roto-till in late autumn, so that many eggs are brought to the surface; the cold getting any that birds miss.
The cold also helps clean the soil and improves its texture.

 

[DirtMechanic]

I see the fumigant training manuals indicate nema lower than the control zone. I found the picture useful since it is not a hard to read chart.

 

[marlingardener]

DirtMechanic, you're so helpful with my problem. Thank you (and the potato patch thanks you, also).

 

[DirtMechanic]

The garden has had 4 treatments of Promax at this point, tilled in. Fingers crossed plants go in this week.