How do I connect underground PVC pipe holding wire to rigid conduit?
First, apologies for leaving this question for so long and thank you for your comments.
In the end, I used flexible PVC conduit. I could have used rigid conduit, which was less expensive, but decided against it as there were too many elbows to glue (and not all the turns were 90 degrees).  With the flexible conduit, there was only one junction to glue in the middle and the elbows at the end.