Not for sure it is a virus. You can start a new patch somewhere else to rule it out. If there is no virus you are going to enjoy plenty of raspberry.

thx. for reply.

is there a recommended distance from the existing patch to minimize the potential for transmission? (I already know not to use any planting from the existing patches.)

I don't think that there is a hard and fast answer.

The articles I've seen say to separate black raspberries from red and wild raspberries by anywhere from 150 to 1000 feet to prevent the spread of virus (black raspberries are much more susceptible, so the reds can be carriers). They also suggest planting the "clean" berries upwind to make it less likely the aphids will be blown in. Here and here are two articles which describe this.

I believe I've also had virus problems with my black raspberry (Jewel). Given that there are no points in my yard more than 250 feet apart and wild berries abound, I had the black raspberries near the rest of the berries. For the last two years, they have been discolored (yellowing leaves) and poorly producing. A couple of the plants died out entirely leaving gaps in the row. What little they make gets eaten by the birds, though I got 3-5 (berries, not pints...) this year. It's also possible that the soil is a bit too moist for them, though the nearby triple crown blackberries seem to be fine. Either way, I ripped them out a month ago and am planning on replacing them with blueberries which shouldn't be susceptible to the same virus (if present) and will better tolerate moist ground(sometimes squishy, rarely a small amount of standing water).

Are you raspberries summer (fruit in mid summer on 2nd year canes) or fall (Aug/Sep on 1st year canes, which often also bear the next year on 2nd year canes in summer) bearing? If they are summer bearing, when exactly did you cut all the old ones down? If it was fall 2011, which lead to "New canes grew like crazy this year", you may not have a problem, as they will fruit on those canes next year.

Bob; thx for reply. my berries are summer so I did not expect fruit from the older patch I mowed down last year at the end of the season. However, the new patch next to it was on it's 2nd year and should have yielded nicely.

My plan now is to give the existing patches another year while simultaneously starting a 3rd patch with new nursery plants. I will plant them upwind but won't make the 1000' separation. thx for the help and links.

I'm probably not that many miles from you. I had a bumper summer crop with Boyne and a lousy fall crop with Autumn Britten. I didn't water the fall crop at all though. I diverted what little collected water that I had to the blueberry bushes. The Britten did set loads of berries, but they just never ripened.

I have a lot of wild raspberry in my area and I suspected that they are often virus carriers. I went on a campaign before planting, to eradicate all the wild ones that I could within 500 ft. That was the distance that I had read somewhere.