High Quality Content by WIKIPEDIA articles! Thomcord is a seedless table grape variety and a hybrid of the popular Thompson Seedless or Sultanina grape (a Vitis vinifera variety) and Concord grape (a Vitis labrusca variety). Thomcord was developed in 1983 by Californian grape breeders working for the Agricultural Research Service (ARS), an agency of the United States Department of Agriculture (USDA), as part of a test to better understand a new seedless grape breeding procedure.