Reduction of sward height in the fall and winter as a strategy to improve the structure of marandu palisadegrass (Urochloa brizantha syn. Brachiaria brizantha cv. Marandu)

Abstract

Reduction of sward height in the fall and winter as a strategy to improve the structure of marandu palisadegrass (Urochloa brizantha syn. Brachiaria brizantha cv. Marandu) Reducción AbstractThe objective of this study was to identify defoliation strategies that might improve the structure of Urochloa brizantha (syn. Brachiaria brizantha) cv. Marandu (marandu palisadegrass). The following 3 defoliation strategies were compared in a plot study: sward kept at 15 cm in fall and winter (W) and 30 cm in spring (Sp) and summer (Su) (15W-30Sp-30Su); sward kept at 30 cm during the entire experimental period (30W-30Sp-30Su); and sward kept at 45 cm in fall and winter and 30 cm in spring and summer (45W-30Sp-30Su). The experimental design was completely randomized, with 4 replicates. Plots were cut with shears to the appropriate height weekly in winter and twice weekly in spring, summer and fall. Tiller density, mean tiller weight, leaf area index, forage mass, percentage of live leaf blades and percentage of stems were measured every 28 days. Forage mass in winter was directly related to pasture height (P<0.05) but differences had disappeared by summer (P>0.05). Mean tiller density was independent of cutting height but was higher in spring and summer than in winter (P<0.05). Mean tiller weight in winter was directly related to cutting height (P<0.05) but differences had disappeared by summer. The percentage of live leaf blades in the swards was affected by season with spring>summer>winter and by cutting height in fall/winter with leaf percentage inversely related to cutting height. Stem percentage in the swards in winter was directly related to cutting height. Grazing studies seem warranted to determine if these plot results are reflected under grazing conditions and what the impacts are on animal performance.Keywords: Herbage mass, leaf area index, morphological composition, tillering. ResumenEl objetivo del estudio, conducido en Uberlândia, Minas Gerais, Brasil, fue identificar estrategias de defoliación con el fin de mejorar la estructura de una pastura de Urochloa brizantha (sin. Brachiaria brizantha) cv. Marandu. Se compararon 3 estrategias: (1) mantener el pasto a una altura de 15 cm en otoño e invierno (W) y de 30 cm en primavera (Sp) y verano (Su) (15W-30Sp-30Su); (2) mantener el pasto a una altura de 30 cm durante todo el período experimental (30W-30Sp-30Su); y (3) mantener el pasto a una altura de 45 cm en otoño e invierno y de 30 cm en primavera y verano (45W-30Sp-30Su). El diseño experimental fue completamente al azar, con 4 repeticiones. Las parcelas se cortaron con tijeras a la altura respectiva semanalmente en invierno y 2 veces por semana en primavera, verano y otoño. se midieron la densidad de brotes, el peso medio de los brotes, el índice de área foliar, la masa de forraje, el porcentaje de hojas vivas y el porcentaje de tallos. La masa forrajera en invierno se relacionó directamente con la altura del pasto (P<0.05), pero las diferencias desaparecieron en verano (P>0.05). La densidad media de los brot...

Contribution of tiller age category to herbage accumulation of Marandu palisadegrass under two fertilization regimes

“…Thus, In early March 2016, pasture was cut at 5 cm above the ground. Thereafter, canopies were maintained at a 15 cm steady state during fall and winter, and 30 cm during spring and summer, according to the recommendations of Costa et al (2016) and M. E. R. Santos et al (2017). In tropical pastures with a high leaf area index (LAI), the herbage accumulation is lower at times of the year under stressful abiotic factors (e.g.…”

“…For this reason, in our study, we adopted the seasonal defoliation management of Marandu palisadegrass (15 cm in fall and winter and 30 higher defoliation intensity in fall and winter, compared to spring and summer, is necessary to maximize herbage accumulation (Sbrissia et al, 2020). For this reason, in our study, we adopted the seasonal defoliation management of Marandu palisadegrass (15 cm in fall and winter and 30 cm in spring and summer), necessary to increase tillering in spring (Costa et al, 2016;Pessoa et al, 2016), to improve the sward structure (M. E. R. Santos et al, 2017) and forage production (Terra et al, 2020).…”

Phytometric characteristics and chlorophyll index of “Paiaguás” grass (Urochloa brizantha) as a function of wood ash doses and soil water stress

“…This indicates the moment of entry and exit of animals in the area. The canopy height also correlates and influences the structural characteristics and the mass of the forage (Santos et al, 2017), making possible the understanding of these structures and the behavior of the animals to plant variations (Fonseca et al, 2013). Dabrowski et al (2013) found a high correlation coefficient between plant height and leaf area index.…”