Ryegrass - the most popular agricultural grass species - comes in four forms: perennial, Italian, westerwold and hybrid.

The hybrid is the progeny of two of these ryegrasses: Italian and perennial. It has characteristics from both parents and therefore provides farmers with a high yielding grass (an Italian ryegrass trait) which is more persistent (characteristic of its longer lived perennial ryegrass parent).

So a hybrid ryegrass such as AberEcho and AberEve last for around four years and have yields nearly the same as the high yielding Italian form. These grasses are therefore included in many mixtures as their benefits are clear.

These hybrids or crosses are not the same as F1 hybrids and should not be confused. F1's have been used with incredible success for maize production throughout the world. F1 hybrid seeds produce infertile plants and will not breed true again, which is not the case with Hybrid ryegrass.