Ok.   I cannot speak officially for Apex, to the best of my knowledge you are out of luck.   The Shapefile import into Apex was designed for bringing in management zones.   I'm not aware that there is any way to export a management zone as a variety layer for variety locator.   This option is avalable in other software available from other vendors, and be aware that my company authors such a software package.  And also be aware that I have very few hours logged onto an Apex box.   Therefore you need to confirm that this functionality does or does exists from a more reliable source.   I would call Stellar Support and ask specifically:

1. Can I import logged as-planted sites from a shapefile into Apex?
2. If so, can I treat this imported layer as a logged field operation?
3. If so, can how can I link a shapefile column to an Apex product?
4. And, can that resultant imported field operation be exported as a variety locator layer?

If the answer to 1 is no, then

1. Can I import a polygon shapefile into Apex and use it as the basis for variety locator?

If you get a yes to any of those questions, post back with any instructions they give you, and I'll help you get your data converted.    The good news is that you are asking this question in June, and not in September.   Thank you for that :)

Please let us know what you find out.