Performances of three lines of limpograss (Hemarthria altissima) in mixed pasture

Abstract

Three tetraploid lines of the sub-tropical grass, Hemarthria altissima (poir) Stapf. et C.E. Rubb. (limpograss), were compared as components of grazed temperate pasture under two levels of nitrogen (N) fertiliser (N nil and N300 kg/ha) for 4 years in northern New Zealand. Mean total (and limpograss) herbage yields (t dry matter (DM)/ha per year) were: N nil, 12.4 (4.0); N300, 18.4 (12.2). Swards containing ‘Bigalta’ and ‘Floralta’ were similar yielding under both N levels and higher than PI349753 under N300. Limpograsscontentsdeclined in all six swards but more slowly under N300. Line PI349753 was least persistertt with and without N. ‘Bigalta’ was more frost-susceptible than ‘Floralta’ and less compatible with associated temperate species, being much less abundant under N nil but more dominant under N300. Taking into account leaf:stem ratio, DM digestibility, and crude protein, overall herbage quality declined in the order: ‘Bigalta’, ‘Floralta’, PI349753. With better than average summer rainfall, ‘Bigalta’ and ‘Floralta’ N300 swards produced 14–16.2 t DM over the November-April warm season with limpograss DM digestibility 68–72% and crude protein 12–13%.

Keywords:

• limpograss
• pasture
• Hemarthria altissima
• ‘Bigalta’
• ‘Floralta’
• nitrogen