Updated project metadata. Cycling Dof Factor (CDF) transcription factors have been implicated in different aspects of plant growth and development. In Arabidopsis and tomato, two members of this family CDF1 and CDF3 have recently been associated with the regulation of primary metabolism and abiotic stress responses, but their roles in crop production under open field conditions remain unknown. In this study, we compared growth and tuber yield and composition of wild-type (WT) potato plants and plants ectopically expressing the CDF1/3 genes from Arabidopsis under the control of the 35S promoter cultured under growth chamber and open field conditions. In growth chambers, the 35S::AtCDF1 and 35S::AtCDF3 potato plants showed higher than WT biomass production and tuber yield. Under field conditions, 35S::AtCDF1 plants showed significant increases in tuber yield with a significant increase in tuber weight, whereas 35S::AtCDF3 plants showed no significant changes in yield, but produced more than WT number of tubers. Metabolomic analysis revealed that tubers of 35S::AtCDF1 plants cultured under open field conditions accumulated higher levels of glucose, starch and amino acids than WT tubers. Comparative proteomic analysis of tubers of 35S::AtCDF1 and control plants cultured under open field revealed that these changes can be accounted for by changes in the expression of proteins involved in energy production and different aspects of C and N metabolism. Results from this study advance our collective understanding of the role of CDFs and are of interest to improve yield and breeding of crop plants