Seed yield of simple and tri-linear corn (Zea mays L.) hybrids for the mexican humid tropics

The objective of the work was to evaluate the agronomic performance and seed yield of tropical corn (Zea mays L.) of single and tri-linear crosses. In the spring-summer of 2015 and 2016, two essays were established in the states of Veracruz and Tabasco, Mexico. In the first essay, a group of 12 single crosses was evaluated, and in the second, a group of 18 tri-linear crosses was evaluated. In both essays, the treatments were distributed under a completely randomized block design with three replicates in 5 m long, two-row plots and 0.8 m between rows, with an initial population density of 62.500 plants ha-1. Within the simple cross trial, hybrids HE-3W, COMERCIAL 1, LT-164xLT-165, and HE-1W presented seed yields above the general mean (3384 kg ha-1). Within this outstanding group is the LT-164xLT-165 cross, which participates as a female parent in the formation of the recently released commercial hybrid H-567. In the tri-linear crosses essay, a group of varieties and hybrids including H-567, (LT-164xLT-165) xLT-156, (LT-164xLT-165) xLT-155, (LT-154xLT-155) xLT-165, VS-536, H-520, VS-563, (LT-154xLT-155) xLT-170, (LT-171xLT-172) xLT-156, (LT-164xLT-165) xLT-164, and (LT-171xLT-172) xLT-170 recorded seed yields of 6669.8, 6515.4, 6498.6, 6431.1, 6260, 6024.7, 5935.4, 5664.3, 5580.8, and 5527.1 kg ha-1, respectively. The LT-154, LT-155, and LT-156 lines are common as a male and female parent, suggesting a good genetic combination. The prevailing environmental conditions during the development of the experiments did not significantly influence the productivity of the crosses. There is genetic variability that can be used to continue developing lines, open pollination varieties, and corn hybrids.