Effects of endophyte infection on dry matter yield, persistence and nutritive value of perennial ryegrass in Galicia (north-west Spain)

Resumen

Dry matter yield, persistence and three parameters of nutritive value were determined in two perennial ryegrass (Lolium perenne L.) genotypes either infected with a lolitrem B-free fungal endophyte or not infected, over a four-year period at two different locations in north-west Spain. The endophyte did not influence the productivity or persistence of perennial ryegrass in the four years of study. Insufficiently stressful conditions could explain these results. The nutritive value of the plants was not influenced by endophyte infection, except for organic matter digestibility and water-soluble carbohydrates on some occasions (P < 0.05). The organic matter digestibility mean value (2 significant comparisons out of 8) was slightly higher in infected ryegrass (72.4 and 83.4%) than in ryegrass free of endophyte (70.3 and 82.6%). The water-soluble carbohydrates mean content (2 significant comparisons out of 8) was higher for endophyte-infected (18.5 and 26.3%) than for endophyte-free ryegrass (17.3 and 24.6%). These differences were small and are insufficient to recommend endophyte-infected perennial ryegrass for forage production in the study areas