Microscopes

[bkay2000]

What power (is that the right term?) of microscope would you need to see nematodes? (I understand I will have to dissect the root carefully.)

There are bunches of them on craig's list (from $50 to $600), but I have no idea what would be required.

bkay

[Tigger]

I don't think it has to be special. With a good eye, you can see them with a jeweler's loupe. 20x, maybe?

[Pieter]

Tigger, bkay is talking about root knot nematodes. I just did a quick google on these nems and found this https://en.wikipedia.org/wiki/Root-knot_nematode and from the first picture you see it would appear as if a much higher magnification is needed. While 500 times magnification is shown, you can probably get away with 100x.

[Chris_W]

Honestly I think you shouldn't worry about it to that extent. Wash your hands and your tools after handling hostas and work to prevent any cross contamination. When repotting loosen the old soil into a trash bin - not into your fresh soil bin - and do one plant at a time, washing your hands in between. There are a lot of different nematodes out there, some good and some bad, and whether or not you can see them won't really make much of a difference in the garden (or pot garden) situation. Prevention and sanitation will be your best defense against these guys. Invest in some lysol concentrate and a spray bottle, and get some disinfecting wipes.

I use Lysol I.C. concentrate and buy it in a gallon jug for about $20.00. This makes 256 gallons of spray and it works as a cleaner and disinfectant. It works as a fungus, bacteria, and nematode killer on surfaces, so this will be your best defense when handling plants. You can also buy the foaming lysol I.C. in a spray can for about $3.00 each. Both of these can be used directly on plants when dividing or repotting (dilute the concentrate first). We use a lot of it on all work surfaces, soaking tubs, to disinfect pots, and even put it directly into the water we use to soak hostas. It could also be a direct contact slug killer, and it has the potential to repel deer and rabbits. Just keep in mind that it can take the blue wax off of blue hostas.

A hosta can carry root knot nematodes and you might not even know it unless the nematode concentration in the roots gets high enough to cause drought stress like you saw. If that happens then pitch it and spend your microscope savings on a new plant.

I hope that helps.

Chris

[bkay2000]

I need some way to figure out when the plants get clean. If I'm going to all the trouble and expense to try to save my hosta, I'd like to know when they are healthy again.

They are still dropping like flies. An Irish Luck that looked fine 2 months ago is almost dead. My beautiful Paul's Glory looks like it has them. My little Bridegroom looks like it has them. It was fine this spring. I talked about putting it in with the new one I got last year. I'm sure glad I didn't. At the rate I'm going, I'm going to be out of the hosta business by fall.

bk

This is one that I lost. You don't just buy another hosta to replace something like this. It took 5 years to get this big. It was over 36" wide in a pot in Texas.

[Chris_W]

What about sending root and soil samples of each of your hostas out for testing? I found that the University of NC only charges $10 for an out of state nematode analysis ($3 in state) where Michigan State charges $25. What did you get charged for your previous samples? If we look around we might find some cheaper options.

And I'm sorry I upset you. I thought it was just a few hostas and didn't know it was a widespread problem.

[bkay2000]

TX A&M charges $35.00 per test. It's a diagnostic test, not just nematodes. They tested for HVX and fungus. They also informed me that my plant had chlorosis.

Sounds like NC has a good deal.

Thanks

bk

[Tigger]

You could try Dr. Grewal at U Tenn. he's doing the research on foliar nematodes in hostas, and might be interested in other nematode afflictions.

[bkay2000]

Thanks, Tigger, I already tried that. He did not respond to my email.

bk

[ycn4chin]

Thanks, Tigger, I already tried that. He did not respond to my email.

bk

I heard that he took a position at another University.

[ViolaAnn]

So sorry to hear of your plight.

I've had increasing numbers of nematodes each year but only a few plants are badly affected. I have a jewelers loupe. It's just 10 x 23mm but is plenty strong to see them swimming in water with a cut-up leaf under a bright light. But, as said above, why? The symptoms are quite clear.

I'd like to know more about using Lysol. Is it a good thing to spray over the cut foliage in the autumn? Or if I give up on a single plant? But mostly when potting up divisions of a plant. Sounds like an easy thing to do if it works. I've been reluctant to share some of my hostas, though it's becoming increasingly obvious that the nematodes are just about everywhere.

[bkay2000]

Thanks, Ann.

My problem is root knot nematodes, not foliar nematodes. Bill Meyer said it was some kind of root rot that was the real problem. He said that they might have nems, but rot was the real problem. (I actually think he was right.) I double checked with A&M, they found no evidence of fungi. I had some other photos that I sent to Bob Solberg (thinking he's in the south and might be familiar with root knot nems). He said it looked like root knot nems to him.

I bought some Nemakill, but ended up heat treating them. I've tossed several. I have a few left. We'll see what we see.

Thanks for your thoughts, though.

bk