Ted: I've never heard of any apple rootstock resistant to nematodes. Commercial growers fumigate before replanting in nematode infested areas. That's probably not a viable option for you. I did it once but cann't remember the name of the material I used right now.

Another pointer is that you should use a more vigorous rootstock than you would in the absence of nematodes. Probably nothing smaller than M7, maybe even seedling.

The Fruitnut

I didn't know apples GOT nematodes. Shame on me, and I'm just about a professional. If you can, anywhere you can plant rye. The nematodes will go into the roots and you and then I turn under. After that you can use 5# sugar or I think 1Qt. heavy molasses in water per 100 sq. ft. I also mulch mine (everything for that matter) with leaves over weed mat. That is another deterrant. You could also plant French marigolds from Park Seeds around the trees. They are not heavy feeders, & attract bees. I have never had any problems with root know varieties.

Yes they do, according to UCD:

http://www.ipm.ucdavis.edu/PMG/r4200111.html

Carla in Sac