Ursula Ruiz-Vera, Riley Balikian, Timothy Larson, Don Ort

Cassava (Manihot esculentaCrantz) production will need to be improved to meetfuture food demands in Sub‐Saharan Africa. The selection of high‐yielding cassavacultivars requires a better understanding of storage root development. Additionally,since future production will happen under increasing atmospheric CO2concentra-tions ([CO2]), cultivar selection should include responsiveness to elevated [CO2].Five farmer‐preferred African cassava cultivars were grown for three and a halfmonths in a Free Air CO2Enrichment experiment in central Illinois. Compared toambient [CO2] (~400 ppm), cassava storage roots grown under elevated [CO2](~600 ppm) had a higher biomass with some cultivars having lower storage rootwater content. The elevated [CO2] stimulation in storage root biomass ranged from33% to 86% across the five cultivars tested documenting the importance of this traitin developing new cultivars. In addition to the destructive harvests to obtain storageroot parameters, we explored ground penetrating radar as a nondestructive methodto determine storage root growth across the growing season.