Tiller demography of Urochloa decumbens under different deferral times: appearance, mortality, and survival rates.

• DOI: https://doi.org/10.22533/at.ed.1411126130110

• Palavras-chave: -

• Keywords: Urochloa decumbens; tiller appearance rate; tiller survival; pasture deferral; forage management

• Abstract:

  Understanding tiller population dynamics in tropical grasses under different management strategies is critical for improving pasture persistence and forage productivity. This study evaluated the tiller demographic rates (appearance, mortality, and survival) of Urochloa decumbens cv. Basilisk under three deferral periods (30, 60, and 90 days) during the dry season in the Central-West mesoregion of Minas Gerais, Brazil. A randomized complete block design with four replicates was used. Tiller demographic variables were assessed for both total (PT) and basal (PB) tiller populations based on generational tagging at 28-day intervals. Prior to analysis, variance homogeneity was confirmed by Levene's test (p > 0.05 for all variables) and one-way ANOVA was applied at α = 0.05. No significant differences (p > 0.05) were detected among treatments for any tiller demographic variable. Tiller survival rates were 50.78, 47.87, and 53.95% (PT) and 54.28, 51.48, and 54.16% (PB) for 30, 60, and 90 days, respectively. Tiller appearance rates showed a non-significant numerical trend of increase from 30 (13.12%) to 90 days (23.73%) for PT. These results indicate that tiller population stability in U. decumbens is maintained across a range of 30 to 90 days of deferral, even though morphogenetic and structural characteristics were significantly affected by deferral duration in parallel studies. The demographic resilience of tiller populations under extended deferral complements previously published data on morphogenetic traits and forage compositional quality of U. decumbens under this management system.