Trenched rigid conduit? As in conduit buried in a trench in the ground?

If so, no - I would not use that cable. It isn't DB rated. All too common mistake is buried conduit is not water tight no matter how carefully it is installed. Regular PVC jacket on cables will break down over time because they aren't designed to be sitting in the water, muck, and mire that will accumulate in the conduit within about a week of installation. Only use DB rated cable in conduit.