Abstract

DIAZ ROMO, Abraham et al. Aerial biomass, seed quantity and quality in Melinis repens (Willd.) Zizka in Aguascalientes, Mexico. Rev. mex. de cienc. pecuarias [online]. 2012, vol.3, n.1, pp.33-47. ISSN 2448-6698.

In the present study, aerial biomass output and seed yield, viability, germination, and dormancy were evaluated in Melinis repens (Natal grass) growing at different locations in Aguascalientes, México. Four grazing excluded sites with high population of Natal grass were selected in the municipalities of El Llano, Jesús María, San Francisco de los Romo and Calvillo. In October 2008 and 2009, forage and seed were harvested by hand. Forage and spikelet yield and seed number were estimated. Seed viability, germination and dormancy were evaluated at different post harvest times. Significant differences were found in aerial biomass output, with means from 2,913 to 1,736 kg DM ha^-1 in 2008 and from 1,488 to 707 kg DM ha^-1 in 2009 (lower rainfall); Calvillo site showed higher production. Seed yield showed differences (P<0.05), ranging from 1,239 to 2,401 seeds m^-2 in 2008 and from 1,452 to 3,906 seeds m^-2 in 2009. Seed viability means went from 32 to 54 %, without significant differences. In Calvillo, seed germination (25 %) was higher than in the other sites, and was similar to viability at 18 mo post harvest (43 %), but in El Llano, germination was lower (2 %) because of higher dormancy, with low increment even at 24 mo post harvest, reaching only 15 %. This grass presented relatively high levels of aerial biomass and seed yield, and these factors can favor invasive ability of this species. Seed yield and dormancy were greater in unfavorable moisture conditions.

Keywords : Natal grass; Melinis repens; Forage yield; Seed; Viability; Germination; Dormancy.

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