The information on yield and yield components is very important for breeding of purple waxy corn (Zea mays L.var.ceratina) before the new varieties are released to the farmers. The objective of this investigation was to determine the effects of location, variety and their interactions on yield, yield components and agronomic characters of five varieties of purple waxy corn at milky and maturity stages. Field experiment was carried out in a randomized complete block design with three replications at two locations in Uthai Thani and Khon Kaen, Thailand in the dry season 2014/2015. Location, variety and location by variety interactions were significant for yield at both milky and maturity stages except the interaction between location and variety for yield at maturity stage. Most
interactions between location and variety had low contributions to total variations in yield at maturity stage, ranging from 2.9% to 9.8% except the interactions for seed yield (23.4%) and corn husk (17.3%). The results suggested that stable variety may be selected across locations. Khon Kaen had higher yield than Uthai Thani but the crop had longer maturity due to lower temperature at vegetative period. FC111 had the highest yield of 4,060 kg Rai-1 followed by KGW5 (2,824 kg Rai-1). FC111 also had longer days to maturity (65 days) than did KGW5 (54 days). KND had low yield of 2,364 kg Rai-1 but it had the shortest days to flowering (52 days). The information on yield is very important for anthocyanin production from purple waxy corn.