Objective: To evaluate the response corn hybrids have on their growth of aerial and root parts, transpiration,and water use efficiency during their early vegetative stage in irrigation and drought conditions.Design/methodology/approach: A randomized complete block design with a factorial arrangement, threerepetitions, three corn hybrids and two humidity levels were used. The evaluated variables were: plant height,leaf area, root length, dry weight of the aerial and root part of the plants, efficiency in the water use and totalplant transpiration.Results: The leaf area and dry weight data of the aerial parts of the assessed plants were greater in irrigationthan in drought; in contrast, root length, dry root weight and water use efficiency were higher in drought. SV 3245 registered a higher total transpiration per plant; SV 3243 and ASGROW 7543 showed higher dry weight in their aerial parts; ASGROW 7543 accumulated a greater dry weight at their roots and was more water usage efficient. The experiments indicated interaction for root length, dry root weight and efficiency in water use.Limitations on study/implications: The drought caused seedlings’ death at 28 days after sowing (dds), therefore, it was not possible to continue the evaluations from then on.Findings/conclusions: The drought decreased the growth of the aerial parts of the plants and increased the root system and efficiency in their water usage.