Crimson clover is essentially used as a catch crop in association with ryegrass. The comparative trial conducted in 2019-21 has led to the addition of two new acquisitions to the List of Recommended Varieties of Forage Plants.
Crimson clover is a short-lived but overwintering legume that is quite sensitive to frost. It goes from sowing to flowering in around 60 days. Fairly undemanding in terms of soil type, it nevertheless prefers fertile, semi-heavy soils with a neutral or alkaline pH. Crimson clover is used primarily as a catch crop following a cereal crop. It enables two cuts to be made: a first cut in autumn and the main cut after the winter. This fairly late cut in the spring means that it can only be succeeded by silage maize or potatoes.
Italian ryegrass makes the ideal partner
Crimson clover is rarely used as a pure crop. In principle, it is associated with Italian or Westerwold ryegrass, as in the two standard mixtures for catch crops, 151 (Landsberg mixture) and 155 with alfalfa and ryegrass. These mixtures supply a protein-rich, well-balanced forage.
Fourteen varieties tested in the field
From 2019 to 2021, Agroscope tested fourteen varieties of crimson clover in comparative trials at seven different locations. The following criteria were examined: vigour, yield at first cut and total yield, juvenile development, competitive ability, persistence, resistance to leaf diseases and sclerotinia (white mould), and winter-hardiness. As a low dry-matter content can cause problems with feeding and conservation, dry-matter content at harvest was also determined.
Two new acquisitions retained
The range of varieties tested includes thirteen new varieties and an already recommended variety (Contea), which served as the standard in our trials. Unfortunately, based on the results obtained, none of the thirteen candidates was distinctly better than the standard variety. Since at least three varieties of crimson clover should appear in the List of Recommended Varieties, the two best acquisitions out of the candidates tested, ‘Rokali’ and ‘Red’, were retained, although, strictly speaking, they did not meet the required conditions for a variety recommendation. Rokali and Red had good scores in terms of yield at first cut, vigour, competitive ability and resistance to leaf diseases. Rokali is also characterised by a high dry- matter content at harvest. In terms of resistance to sclerotinia, a serious disease of crimson clover, the two varieties offer no specific advantages over the average of the tested range.
- Crimson clover is an important legume for short-lived mixtures that serve as overwintering catch crops after a main crop.
- From 2019 to 2021, Agroscope tested a total of 14 varieties of crimson clover to find the varieties best suited to Swiss forage production.
- The two acquisitions ‘Rokali’ and ‘Red’ achieved good results for several important characteristics, in particular yield at first cut, vigour, competitive ability and resistance to leaf diseases.
- Although these two varieties do not in principle meet the conditions for a variety recommendation they will nonetheless be added to the List of Recommended Varieties, so that sufficient varieties are available. This is important to allow a minimum supply of seed for our standard mixtures to be guaranteed.
- Together with Contea, which retains its recommendation, there are therefore three recommended varieties on the List of Recommended Varieties of Forage Plants.