This study aimed to evaluate the dynamics of the association of 'capim-de-raiz' (Chloris orthonoton Doell) and alexandergrass [Brachiaria plantaginea (Link) Hitchc], as for persistence and production. Gathering of botanical material, evaluation of botanical composition and forage mass were realized in deferred native pastures. To estimate forage mass, a randomized block design with four treatments was used, consisting of 60, 90, 120 and 150 days of deferring and five replications. The botanical composition was expressed as a percentage of the total.Ten families, 15 genera, and 18 species were identified. In the botanical composition from May to August 2007, alexandergrass was the main component from 60 to 90 days, corresponding to 46.75 and 52.09%, respectively.In August 2007, other species participated with 57.75% of the botanical composition. In the assessment of the year 2008, at the end of the deferring period, other species occupied 100% of the botanical composition of pasture.The highest forage mass (kg DM/ha) for alexandergrass (2,736) occurred at 90 days; for other species (3,141) and 'capim-de-raiz' (2,701), it was at 120 days.The use of stockpiled forage should preferably take place after 60 to 90 days of deferring. After a year without interference, 'capim-de-raiz' and alexandergrass decrease participation in the botanical composition of pasture.