White clover selected for enhanced competitive ability widens the compatibility with grasses and favours the optimization of legume content and forage yield in mown clover-grass mixtures

White clover-grass mixtures should provide swards with a high dry matter (DM) yield with a clover proportion of at least 0 center dot 30. This study assessed the compatibility of one white clover variety selected for competitive ability (Giga) and four other large-leaved clover varieties (Aran, Espanso, Fantastico and Regal) in mown binary mixtures with each of four grass companions (cocksfoot cv. Padania, hybrid ryegrass cv. AberExcel, Italian ryegrass cv. Crema, and tall fescue cv. Magno) over 3 years in northern Italy. On average, the mixtures including Giga had at least a two-fold greater clover proportion in the total harvested DM (P < 0 center dot 01) and contained fewer weeds (P < 0 center dot 10) than those with other clover varieties, and also tended to have the highest total DM yields. On average, mixtures containing AberExcel had clover proportions of > 0 center dot 25 but gave the lowest total DM yields, whereas those of Magno maximized total DM and had a higher proportion of clover than Padania or Crema. No clover x grass interaction was detected (P > 0 center dot 05). The association with Giga allowed the tall fescue-based mixture to attain a clover proportion 0 center dot 331 along with a top-yielding total DM. This mixture, compared with the only one without Giga that displayed a near-sufficient clover proportion (Espanso with AberExcel), exhibited a 21 center dot 7% higher total DM (P < 0 center dot 05) and had far fewer weeds.