The aim of this book was to evaluate the green mass productivity of two transgenic hybrids subjected to different population arrangements. The experiment was conducted in the experimental area of the Centre for Agricultural Sciences and Biodiversity (CCAB) at the Federal University of Cariri (UFCA), in Crato - CE. A randomised block design was used in a 2x2x2 factorial scheme, with three replications, totalling 24 experimental plots. The first factor was transgenic maize (Yeld Gard and Feroz Víptera), the second was row spacing (0.6 and 0.8 m) and the third was plant spacing (0.2 and 0.3 m). The variables analysed were plant and ear height, green mass per plant and green mass of ears with and without straw, and green mass yield. The results obtained show that the cultivars evaluated obtained similar results and that the smaller spacings used made better use of the area, increasing total green mass productivity