The silage yield potential of hybrid ryegrass over a 5-year period in Northern Ireland relative to other ryegrasses and timothy

The yield and persistency of grass species within a managed sward are a major consideration when determining species mixtures for either long-term or shortterm sward management systems. Perennial ryegrass is lower yielding but more persistent than Italian ryegrass. Hybrid ryegrass, an interspecies cross between perennial and Italian ryegrass, may be higher yielding than perennial ryegrass and more persistent than Italian ryegrass. Therefore, the yield and persistency of hybrid ryegrass was investigated in Northern Ireland in five experiments, each harvested over five consecutive years, and compared with that of Italian ryegrass, perennial ryegrass and timothy. The performance of the five grass species were in the expected order; Italian ryegrass was higher yielding than hybrid ryegrass, which was higher than perennial ryegrass, with timothy the lowest, whereas perennial ryegrass and timothy had significantly higher sward densities than the hybrid and Italian ryegrasses. In addition, it was found that the rate of decline in yield and sward density with age was the same for all species. Consequently, this study indicated that the higher yielding Italian and hybrid ryegrasses could continue to out-perform perennial ryegrass for 5 years, opening the possibility of more extensive farming use of these species, particularly in Northern Ireland.