Abstract

REYES-PURATA, A et al. Dry matter production and protein concentration in 21 genotypes of the humidicola grass Brachiaria humidícola (Rendle) Schweick. Universidad y ciencia [online]. 2009, vol.25, n.3, pp.213-224. ISSN 0186-2979.

The objective of this study was to evaluate the available variability in 21 Brachiaria humidícola genotypes with respect to protein concentration and dry matter production, during the dry season of the year. The study was carried out during the March, April and May months of the years 2004 and 2005, with neither watering nor fertilising of the soil. Three harvests were obtained per genotype each year, with a regrowth period that varied from 33 to 35 d between harvests. The experiment was established under a completely randomised design in a split split-plot arrangement. Results showed an important among-genotype variability (p < 0.0001) for protein concentration within the year, that varied from 101.1 to 119.5 g kg^-1 of MS, for the 26 160 and 26 413 genotypes, respectively. The 26 413 and 16 891 genotypes recorded the greatest protein concentrations although not significantly above (p > 0.05) those of the 679 genotype (commercial Humidícola). Moreover, protein concentration presented an important stability in the environment with no interaction with the year or the harvest date (p > 0.05). On the other hand, an inverse relationship was observed between protein concentration and dry matter production: For this reason, a decrease in protein concentration was observed in the harvest material with the greatest dry matter production. This decrease is explained through a decrease in the proportion of leaves in the total aerial biomass of the plant.

Keywords : Protein concentration; dry matter; variability; dry season; B. humidícola.

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