Higher Yielding, More Resistant Cultivars of Main Swiss Forage Grass

Adapted, productive grass cultivars are crucial for Swiss forage production. Over the past 30 years, the most important grass species – perennial ryegrass – has been substantially improved by breeding.

Perennial ryegrass (Lolium perenne L.) is the ideal grass for Swiss forage production. Suitable for mowing and grazing, it responds positively to fertilisation, is suitable for conservation, and produces high yields and valuable fodder. It has been cultivated for almost a century now.

In this study, the new Agroscope cultivars were compared in plot trials from 1990 to 2015 with breeding lines and recommended varieties. The upshot: present-day varieties produce higher yields of dry matter,are significantly more resistant to rust pathogens and exhibit greater digestibility than older cultivars.

This trend is also reflected in the new Agroscope cultivars ‘Araias’, ‘Koala’, ‘Artonis’, ‘Bellator’ and ‘Soronia’, especially as regards yield and disease resistance. They are included on the current List of Recommended Varieties of Forage Plants – with the exception of ‘Bellator’, which only passed the test for distinguishability, homogeneity and stability after the List of Recommended Varieties was published.

More Genes = Greater Productivity

Varieties with a doubled genome (tetraploid varieties) have made particular strides. They are higher-yielding and more disease-resistant than varieties with a single genome (diploid varieties). In terms of breeding, tetraploid varieties are streets ahead of the diploids.

Nevertheless, diploid varieties are potentially attractive for use on meadows, since they show higher tiller production, and are more persistent and more resistant to environmental stress. For this reason, separate variety testing of diploid and tetraploid cultivars makes sense.

In addition, a distinction is drawn between early- and late-maturing cultivars. The relationship between maturity and yield is an important decision-making criterion for when a cut should be made and which variety is chosen. The analysis shows that early-maturing varieties produce higher biomass yields both between and within the different maturity groups. This relationship is especially noticeable in the case of the late-maturity groups.

Agroscope Varieties ‘Artonis’ and ‘Araias’ in the Lead

The Agroscope variety ‘Artonis’ did particularly well, standing head and shoulders above all other early tetraploid varieties in the overall assessment. ‘Araias’, another Agroscope variety, was similarly successful in the early-maturing diploid range.

The upward trend in breeding looks set to continue, especially in the case of the tetraploid varieties. The wide variety of genotypes also shows that further improvements are possible.