Diploid/Tetraploid Ryegrass Perennial, Italian and Hybrid ryegrass occur both in the naturally evolved, diploid form (14 chromosomes) and a tetraploid form (28 chromosomes).
The chromosome number has been doubled, by treating the diploids with the chemical colchicines. “Tetraploiding” ryegrass produced changes in anatomical, chemical and physiological makeup. For example, plants have larger parts such as tiller and leaf size; they have higher moisture and carbohydrate content; they grow at a faster rate; mature earlier and are shorter lived. The values of tetraploids are increased yield at specific times of the year (typically winter) and increased stock utilisation. Tetraploid hybrid, Italian and perennial ryegrass is often direct drilled into existing pastures as a method of boosting productivity during late autumn to midspring. They are a better alternative for annual silage production. Tetraploids are best suited to conditions of high fertility, moist or irrigated conditions and lax grazing management.
In contrast, diploid ryegrass is suitable for hay production over multiple years and is better suited to drier conditions and close grazing. Less cell wall (cellulose) but more carbohydrate means that dry matter production of Tetraploid Ryegrasses is of higher quality and the grass is more palatable.
Diploid Ryegrass Surrey 2 annual ryegrass is a diploid type< which has 14 chromosomes.
Tetraploid Ryegrass Jivet annual Italian ryegrass is a tetraploid. It has double the number of chromosomes (28) for better tillering, faster growth, larger leaf size, higher moisture and carbohydrate content.
Annual ryegrass >(Lolium westerwoldicum) Westerwoldicum is an annual type Italian ryegrass, and the fastest growing ryegrass. Unlike Italian ryegrass, it is able to become reproductive during the sowing year. Westerwoldicum is used when high production is required within 3 - 6 months after sowing and is able to achieve good yields in the winter and early spring. There are only minor differences between diploid and tetraploid varieties.
Italian ryegrass (Lolium multiflorum L) Italian ryegrass is one of the fastest growing grasses. It establishes well, has early spring growth and rapid regrowth that is well suited to grazing or harvesting, offering good digestibility.
Italian ryegrass thrives well in all kinds of soil; making it is suitable for a multitude of uses from conservation to under-sowing and ongoing pasture maintenance.
The new varieties have good persistence and are able to be used for 2 - 3 years in mild climates. Italian ryegrass is available in both diploid and tetraploid.
Festulolium (Festulolium braunii) Perun is an interspecies cross between Italian ryegrass and meadow fescue and the resulting variety possesses the key benefits of both grasses.
Festulolium offers high quality, broad adaptability, excellent heat and cold tolerance, excellent persistence and seasonal growth.
Festuloliums are suitable for use where maximum performance and quality are required in environments that are unsuitable for either perennial or Italian ryegrass.
Hybrid ryegrass (Lolium x boucheanum) Hybrid ryegrass is a cross between perennial and Italian ryegrass - combining yield, quality and persistence.
The types in this product group range in parentage from very perennial to intermediate to very Italian in performance.
Hybrids are suitable for grazing, conservation and make a very good companion in a seed mixture.
Hybrid ryegrasses have improved drought tolerance to Italian ryegrass, especially the very dense hybrids.
Spring growth is generally like early perennial ryegrasses, where as the heading is more like a medium maturity perennial and this gives a great deal of flexibility in spring as it has high quality forage.
Perennial ryegrass (Lolium perenne L) Perennial ryegrass is a high yielding, high quality grass.
Under grazing management, the best varieties are very persistent, provided they are well fertilised and grazing is suitably managed.
In cool areas, it plays an important role in short-term production with high yields and quality.
Perennial ryegrass is compatible in mixtures with white and red clover and is also suitable for sowing into a worked seed bed or for direct drilled.
The varieties are available in early, mid or late heading types and also diploid and tetraploid.
** Rooting depth shown under optimal
conditions. This is a refernce only.• View in Forage Guide flipbook