Foliar nematodes - how early can you find them?

[ViolaAnn]

Hi,

I had a couple of plants that were a bit suspicious for foliar nematode, but not confirmed last summer. It's too early to see their damage yet in Ottawa, but I wondered if I could be finding them in those plants at this time of year should they be infected. I bought myself a jeweler's loupe last summer. If I were to put a cut up leaf in water at this time of year would I find the nematodes if they are in the plant even though I'm not yet seeing symptoms?

[Chris_W]

Yes, if the plants have them badly you should be able to start seeing them coming from the leaves under magnification, but they are easy to miss unless you have a really good magnifier. In the north we don't usually see their actual effects until mid to late August or early September, depending on how hot and/or wet it is during the summer. During hotter summers you don't see the symptoms until later. Cooler and wetter summers you can see them earlier.

I've been wondering the same thing actually. We are going to be propagating some really old clumps of various hostas that we moved here from our old place and though they haven't shown any foliar nematode symptoms in the last 6 years we've had them I'm going to have a nematode analysis done on them just to make sure before they go out into our growing stock. They were virus indexed twice during that time, once by electron microscope, but since we just can't get them any longer by TC I'm going to spend the extra to give them a complete checkup. If it is too early to have a nematode analysis done I'll let you know, but I really don't think it is because we've had it done in the past even earlier than this.

Hope that helps.

Chris

[ThisIsMelissa]

Here in MN, I saw them on July 30th last year.

No signs yet this year, but it's been a bit hotter here than last year, but equally as wet.

[ViolaAnn]

When I checked one of the questionable plants yesterday, there WERE signs of nematodes and I found some in water as well. Now I'm keeping a careful watch on all the plants around it - my entire 'Baby Bunting' family. I appear to have another BB in the back yard that seems fine.

Makes me wonder a bit if they aren't inevitable.