Dinámica de tallos de pasto ovillo (dactylis glomerata l.), solo y asociado con ryegrass perenne (lolium perenne l.) Y trébol blanco (trifolium repens l.)

The objective of this study was to determine the population dynamics of orchard grass stems (OG) (Dactylis glomerata L.), alone and associated at different proportions with perennial ryegrass (PR) (Lolium perenne L.), and white clover (WC) (Trifolium repens L.) under grazing conditions. The treatments were the following combinations: 100:00:00, 20:40:40, 40:20:40, 50:00:50, 20:70:10, 70:20:10 and 40:40:20% of OG: PG: WC, respectively. They were distributed in 27 experimental units, based on a completely random block design with three repetitions. The variables evaluated were: plant density (PD), stem population density (SPD), appearance rate (AR), death rate (DR) and stem survival rate (SSR). The highest average PD was recorded during fall with 25 plants per m2 in the association 50:00:50 of OG: PG: WC (P<0.05). In SPD, the results show differences (P0.05) between associations; however, a very variable behavior was observed, with summer (736 stems m2) being the time when the highest OG densities were found (50:00:50; P0.05). The association 20:40:40 of OG: PG: WC, presented the highest AR in December (7.3 stems *100 stems d1). The association 40:20:40 of OG: PG: WC obtained the highest DR with 5.4 stems *100 stems d1, during the month of March (P0.05). In general, orchard grass presented the highest dynamic of stems with the associations 20:40:40 and 40:20:40 of OG: PG: WC being the ones that presented the highest AR and DR.