Variety Testing in Forage Production: Two Interesting New Hybrid Ryegrass Cultivars

Hybrid ryegrass is a high-yielding, versatile forage grass used in many clover-grass mixtures. Out of a total of 23 tested varieties, two new varieties performed particularly impressively in terms of yield and resistance to bacterial wilt.

The variety trials of over 20 species of grasses and legumes conducted by Agroscope enable the continuous updating of the List of Recommended Varieties of Forage Plants. This list forms the basis for the creation of seed mixtures of faultless quality, and is an indispensable guide for the Swiss seed trade, ensuring that advances in breeding developed over many years by the breeders are passed on to practitioners.

Variety testing for hybrid ryegrass

Hybrid ryegrass is a cross between Italian and perennial ryegrass. Depending on the crossing method, the progeny more closely resemble the Italian or perennial variety. Three types of hybrid ryegrass are therefore distinguished: Italian (I), perennial (P) and the hybrid type (I/P). Whereas the Italian and hybrid types are most suitable for mowing, the perennial type can also be used for grazing.

Hybrid ryegrass is a valuable, fast-growing forage grass. It is mainly used in three-year clover-grass mixtures in which ryegrasses with better persistence than Italian ryegrass are required. Good varieties must not only be persistent, however, but also high-yielding, competitive, and as disease-resistant as possible.

Field trials at six sites

In three-year field trials from 2018 to 2020, Agroscope tested 23 new and already-recommended varieties as to their suitability for cultivation. Yield, forage digestibility, vigour, juvenile development, competitive ability, persistence, winter-hardiness and resistance to bacterial wilt and leaf diseases were assessed. The trial results were evaluated separately according to growth type. Sixteen of the 23 varieties tested in total belong to the hybrid type (I/P).

Two new varieties of the hybrid type are clear winners

Two new cultivars, namely, LH 1255 and LH 1325 – both of the hybrid type – have cleared the hurdles for inclusion on the List of Recommended Varieties of Forage Plants. Among the 16 varieties of the hybrid type tested, they swept second (LH 1255) and fourth place (LH 1325). The significant improvement shown by both cultivars was in resistance to bacterial wilt. Together with the recommended variety ‘Rusa’, they performed best for this trait. They also achieved very good results in terms of yield. In addition, the variety LH1255 impressed with very good scores for persistence, vigour and winter-hardiness. By contrast, the results of both cultivars for digestibility were only mediocre. Since this criterion is only single-weighted in the evaluation, it had no effect on the overall results, or on inclusion as a recommended variety. Both varieties are currently undergoing official testing for distinctness, uniformity and stability, and can only be definitively recommended after conclusion of the testing. The previously recommended varieties ‘Antilope’ and ‘Dorcas’ performed unsatisfactorily overall, causing them to lose their variety recommendation.