Resumo

TADEO-ROBLEDO, Margarita et al. Productivity of F ₁ and F ₂ maize (Zea mays L.) Hybrids in the highland of Mexico. Agrociencia [online]. 2016, vol.50, n.1, pp.33-41. ISSN 2521-9766.

In Mexico 8.5 million ha of maize (Zea mays L.) are sown each year. Hybrid seed is used in about 25 % of this area, and in the rest, local varieties (50 % genuine maize landraces and 25 % locally adapted, improved varieties or advanced generations of hybrids). The hybrid seed use is concentrated in areas of high productive potential. Each year there is reluctance to acquire new seed due to its high cost. To verify the yield of F1 and F2 hybrids, an evaluation was made of varieties H-40, H-51 AE, H-57 AE and Puma 1167 in the spring -summer cycle of 2013 by the Cuautitlán Graduate Studies Department of UNAM. The experimental design was complete randomized blocks with four replicates. The statistical analysis was carried out in a factorial design with the following factors: hybrids (4), population densities (2), generation F1 and F2 (2), as well as the hybrid interactions x F1 F2, hybrids x PD, F1 F2 x PD, hybrids x F1 F2 x PD. The analysis of variance detected highly significant differences for yield among hybrids and generations F1 and F2, and significant differences among population densities; none of the interactions was significant. The CV was 12.0 % and the average value was 8422 kg ha-1. The F1 generation yielded an average of 9040 kg ha-1, and the F2 , 7804 kg ha-1. The hybrids with the highest yields were Puma 1167 (9989 kg ha-1) and H-57 AE (8334 kg ha-1). Compared to a population density of 70 000 plants ha-1 (8765 kg ha-1), a higher yield was obtained than with 55 000 plants ha-1. The results confirm that the use of the F2 generation of seed is not desirable, due to the decrease in productivity.

Palavras-chave : Zea mays L.; improved seed; yield of F₁ and F₂ hybrids.

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