Field’s promoted from an InfoPath form template during publishing to a Microsoft Office SharePoint Server are created multiple times

When publishing an InfoPath Form Template (XSN file) to multiple servers (i.e. a development server and a production server) and you are promoting fields from the InfoPath data source to be created as columns in SharePoint, those fields may get recreated each time you publish the XSN.

See the following post for more information:
Field’s promoted from an InfoPath form template during publishing to a Microsoft Office SharePoint Server are created multiple times