PSXI-40 Morphogenetic characteristics of signal grass pastures in monoculture and intercropped with forage peanut.

摘要

The objective of this study was to evaluate the morphogenetic characteristics of signal grass ( ) pastures in monoculture and intercropped with forage peanut ( cv. Belmonte), managed under rotational stocking by crossbred dairy cows, using three row spacings (40, 50 and 60 cm) and two post-grazing sward heights (5 and 15 cm) + an additional treatment of signal grass monoculture, in a 3x2 + 1 factorial scheme using a randomized block design with four replicates. The morphogenetic evaluation took place from January to April 2015 and from February to April 2016. Two points per paddock were selected, with three tillers spaced 1 m apart, which were marked with flexible wires at the beginning of each grazing cycle. Leaf appearance rate (LAR), leaf elongation rate (LER), stem elongation rate (SER), and leaf senescence rate (LSR) were evaluated. A comparison of the averages was done by the Tukey (intercropped pastures) and Dunnet test (intercropped pastures in relation to monoculture), using 5% probability. In 2015, the LAR, SER, and LSR were not affected by treatments. The LER was higher (P <0.05) at 5 cm than 15 cm (1.46 vs 1.08 cm tiller day , respectively), in the 50 cm row spacing. In 2016, the LER, LAR, and LSR were not affected by the treatments. LER was higher (P <0.05) at 5 cm than at 15 cm (0.59 and 0.48 cm tiller day , respectively). Comparing the intercropping pastures to the monoculture, there were no differences among the averages, in 2015. In 2016, the LER showed higher values for 40–5, 50–5, 50-15 and 60–5 (0.65; 0.62; 0.60 and 0.55 cm tiller day , respectively), in relation to the monoculture. The signal grass pastures intercropped with forage peanut showed higher LER when managed at 5 cm post-grazing sward height.