Now that the spring barley has been cut, you can see the grass coming through. This was ‘undersown’ when the barley was planted in the spring. A specially bred variety is used: it is called Festulolium because it is actually a hybrid of Festuca (fescue) and Lolium (ryegrass). There is more about selective breeding of grasses here and more about the particular uses of the many varieties of ryegrass here.
The process of crossing two grasses which are not closely related means that the hybrids are tetraploid. ‘Tetraploid’ means that the cells contain 4 of each type of chromosome: normally in both plants and animals there are only 2 of each type of chromosome. Having twice as many chromosomes means that each cell is much larger: this in turn means that the leaves are larger. (Modern wheat is ‘octoploid’, ie it has 8 of each type of chromosome. This happened as a natural mutation thousands of years ago, but partly explains why a grain of wheat is so much larger than a grass seed.)
The reason that these two are hybridised is that each parent species bring a particular set of desirable characteristics.
The fescue (Festuca) brings high yield and durability:
- high dry matter yield
- resistance to cold
- drought tolerance
The ryegrass (Lolium) brings rapid growth and tastiness!
- rapid establishment
- good spring growth
- good digestibility
- high sugar content
- good palatibility
There are many varieties of this same hybrid, and each has slightly different traits so farmers can be very specific about the qualities of the grass they grow for a particular purpose. The various varieties are created by ‘backcrossing’ the hybrids with either the ryegrass or fescue parent species.
This spring barley was undersown so that there would be a grass ley in place when the barley was harvested. It will be grazed over the autumn and winter, and so the fescue’s resistance to cold will complement the ryegrass’s palatibility and digestibility well for this purpose.