Yanco is a more productive and persistent replacement for the variety Riverina. Across all trials Yanco produced higher winter, spring and total biomass, higher seed yields and higher seedling regeneration densities than Riverina. It is also more hardseeded and has higher resistance to both Races 1 and 2 of clover scorch disease than Riverina. Yanco is suitable for permanent and semi-permanent pastures and to mixed farming. Its upright, vigorous growth makes it well suited to hay and silage production, as well as grazing by cattle or sheep.
Origin
Yanco is derived from a cross between the variety Gosse and a wild plant collected in Turkey. It was evaluated as one of 13 ssp. yanninicum breeding lines and five commercial varieties in trials in WA at Manjimup and Mt Barker and two sites in eastern Australia.
Varietal characters
Yanco flowers approximately 121 days from an early May sowing in Perth (Table 1). It has only a very low level of the oestrogenic compound, formononetin, and will not cause infertility problems in ewes. Yanco is also more hardseeded than Gosse and Trikkala, resulting in greater persistence, particularly after a year in crop.
| Variety | Flowering time | Formononetin | Hardseededness* |
|---|---|---|---|
|
| (days from sowing in Perth) | (% of dry matter) | (% hard seeds in laboratory measurements) |
| Yanco | 121 | 0.15 | 45.5 |
| Rouse | 131 | 0.10 | 23.9 |
| Gosse | 128 | 0.10 | 16.1 |
| Monti | 115 | 0.10 | 21.7 |
| Napier | 140 | 0.10 | 41.7 |
| Riverina | 122 | 0.10 | 24.3 |
| Trikkala | 117 | 0.10 | 14.0 |
| Yarloop | 113 | 1.20 | 12.0 |
*Percent hard seeds remaining after 4 months in a 60/15 °C diurnally fluctuating temperature cabinet
Disease resistance
Yanco is highly resistant to both Race 1 and 2 of the important leaf disease, clover scorch (Kabatiella caulivora) (Table 2). Field observations suggest Yanco has similar susceptibility to the less important disease, powdery mildew (Oidium sp.), as Rouse, Gosse, Monti, Trikkala, Riverina and Napier. Screening has not been conducted for reaction to leaf rust (Uromyces trifolii-repentis) or cercospora leafspot (Cercospora zebrina). However, no significant damage from these foliar diseases has been observed at field sites on Yanco or any of the other ssp. yanninicum varieties. Screening has not been conducted for resistance to any root rot pathogens.
| Variety | Clover scorch disease ratings | |
|---|---|---|
|
| Race 1 | Race 2 |
| Yanco | HR | HR |
| Rouse | HR | HR |
| Riverina | MR | MR |
| Gosse | R | R |
| Monti | R | n.a. |
| Napier | HR | R |
| Trikkala | MR | R |
| Yarloop | HS | MS |
* HR= highly resistant, R = resistant, MR = moderately resistant, MS = moderately susceptible, S = susceptible, HS = highly susceptible, n.a. = not available.
Field performance
Across all sites and seasons Yanco produced 27% more total biomass more than Riverina, 17% more than Monti, 12% more than both Gosse and Trikkala, and 9% more than Napier (Figure 1). In terms of seasonal distribution, Yanco produced 26% more winter biomass and 16% more spring biomass than Riverina. Yanco also produced higher seed yields than all other current cultivars (22% more than Riverina) and maintained higher seed bank densities after two seasons.
Figure 1 Total biomass across all sites and seasons of Yanco and other ssp. yanninicum varieties, expressed as a percentage of Riverina
Seed availability and PBR status
Seed of Yanco can be purchased through Seed Force agencies.
Yanco is protected under the Plant Breeders Rights Act 1994. Under the Act sale of Yanco seed can only be carried out by agreement with the licensee, Seed Force Pty Ltd. However, this does not restrict sale of produce, such as hay or silage, provided seed was legally purchased.
For seed sales information visit seedforce.com.aut seedforce.com.au
