Resumen

VARGAS OLIVEIRA, Lucas et al. Morphogenic characteristic of diploid and tetraploid ryégrass cultivars (Lolium multiflorum Lam.). Zootecnia Trop. [online]. 2014, vol.32, n.1, pp.45-51. ISSN 0798-7269.

Due to the low forage production from native pasture in the winter season in southern Brazil, the use of cool season cultivars pasture grown is an alternative for livestock feed this time of year. The morphogenic knowledge of these plants is essential for decision making in choosing which cultivar should be used in each production environment. With this concern, the aim of this research was to determine, under defoliation, in green house, ryegrass morphogenesis traits of diploid and tetraploid cultivars. Seven treatments were evaluated: three diploid cultivars (Comum-RS, Pronto® and Conquest®) and four tetraploids (INIA Titan®, Winter Star®, KLM 138® and Banquet II®), with six replications in a completely randomized design. Data were submitted to analysis of variance and means compared by Tukey test (P<0.05). Variables evaluated were: leaf expansion rate (LER), senescence rate (SR), leaf appearance rate (LAR), phyllochron (Ph) and leaf lifetime (LL). Significant differences occurred (P<0.0001) for all variables. The materials studied exhibited variability in morphogenesis, defines that the same shall be indicated for different production systems. Banquet II® cultivar, depending on the height pre-cut used and its growth habit, showed reduced number of cuts and higher rates of expansion and leaf appearance. KLM 138® cultivar for its phyllochron and leaf lifetime has lower renewal of leaves in canopy and allows longer intervals between defoliation. INIA Titan® and Pronto® showed rapid regrowth after cutting, which infl uenced the high number of them.

Palabras clave : cutting height; Leaf elongation; Lolium perenne; morphogenesis; senescense.

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