The experiment was conducted in a climate-controlled greenhouse, with two bays, at the USDA-ARS Crops Research Laboratory in Fort Collins, Colorado. In vitro plantlets, from 2- to 3-month-old shoot cultures, of the commercial cassava variety CM 507–37 were transferred to 200 mL plastic cups, containing a commercial potting mix (Fafard 52 mix Conrad Fafard, Inc, Agawam, MA).