Resumo

SANCHEZ HERNANDEZ, Miguel Angel et al. Forage yield in response to sowing density in eight corn (Zea mays) genotypes in the humid tropics of Mexico. Rev. mex. de cienc. pecuarias [online]. 2013, vol.4, n.3, pp.271-288. ISSN 2448-6698.

The purpose was to estimate the forage yield in genotypes of maize with forage potential in response to different sown densities. A first essay (Expl) was made in November 2007 to February 2008, a second study (Exp2) was made in 2009 in Loma Bonita, Oaxaca, Mexico, evaluating the genotypes H-520, HE-1A17, HE-2A15, V-556AC, VS-536, A7573, H-564C and a native variety, in three densities and four replications. Treatments were the combination of genotypes and densities, in a randomized block design. In average of densities native variety had the highest plant height (Exp1=247, Exp2=216 cm), total leaf area (Exp1=5834, Exp2=7516 cm²), stem diameter (Exp1=6.6 cm) and forage yield (Exp1=44.3 t ha^-1). In the second experiment H-564C genotype had the major stem diameter (8.2 cm), number of leaves upper the ear (7.3), ear weight with leaves (251.7 g), ear weight without leaves (148.7 g), ear height (18.0 cm), ear diameter (13.2 cm), yield per plant (564.7 g) and per hectare (36.6 t ha^-1). In average of genotypes, the density of 83,333 plants exceeded in forage yield (Exp1=35.8; Exp2=37.3 t ha^-1) to the density of 62,500 (Exp1=32.1; Exp2=32.1 t ha^-1) and 50,000 plants ha^-1 (Exp1=23.1; Exp2=25.5 t ha^-1). Combined analysis indicated that the native variety produced more forage than hybrids. For density, the maximum yield by genotype was established at 83333 plants ha^-1 the native variety; it produced 57.1 t ha^-1 of forage, above the maximum yield of H-520 and the control VS-536 in that density.

Palavras-chave : Zea mays L.; Hybrids; Varieties; Synthetics; Leaf Area.