If you mean "per plant", the heaviest yielders have been Sativas living in tropical climes ... they can become perennials there. Indicas are restricted by only having the one season to sprout, grow, flower. cn
<edit> I wish I could find the pic again ... of a Sativa near the Equator that was over 50 feet tall, 20 feet across and had several main stems, each as thick as a typical adult's arm. Plants like that have yeilded north of 10 pounds each, and clearly took more than one season to attain that mass.