Origin
Narrikup was released by the Department of Primary Industries and Regional Development (DPIRD) in 2011, and is derived from a cross between the variety Denmark and a wild plant collected in Sicily with seedling resistance to RLEM. Breeding and selection was conducted by Dr Phil Nichols of DPIRD. It was evaluated over three years as one of 12 breeding lines and 6 commercial varieties in trials in WA at Williams, Kojonup and Esperance and three sites in eastern Australia. Trials were conducted without use of insecticides to allow the improved RLEM resistance of Narrikup to be expressed. Narrikup is suited to permanent and semi-permanent pastures and to mixed farming systems.
Narrikup is named after the town of the same name in Western Australia.
Varietal characters
Narrikup flowers approximately 126 days from an early May sowing in Perth (Table 1). This is similar to Campeda, Junee and Woogenellup, 2-3 weeks later than Bindoon, Seaton Park and York, and about a week earlier than Coolamon. Fresh leaves of Narrikup contain only trace levels (<0.05% of dry matter) of the oestrogenic compound, formononetin (Table 1). This indicates a very low potential to cause ewe infertility or difficult lambing.
Laboratory measurements indicate Narrikup is moderately soft-seeded, with similar levels to Bindoon and Seaton Park (Table 1). This makes Narrikup suited to permanent and semi-permanent pastures with occasional cropping. It is not suited to 1:1 crop/pasture rotations. There is no information at present on relative tolerance of Narrikup to herbicides commonly used on subterranean clover pastures.
| Variety | Days to first flowering | In areas where cultivar is suited | Hardseededness* | Formononetin | |
|---|---|---|---|---|---|
|
| (Perth sown early May) | Flowering begins | Seed formation | 0 = all soft 10 = all hard | (% of dry matter) |
| Narrikup | 126 | Mid-Sept | Mid-Nov | 3 | 0.00 |
| Bindoon | 108 | Early Sept | Late Oct | 3 | 0.10 |
| Seaton Park | 110 | Early Sept | Late Oct | 3 | 0.10 |
| York | 110 | Early Sept | Late Oct | 5 | 0.05 |
| Campeda | 123 | Mid-Sept | Mid-Nov | - | 0.00 |
| Junee | 129 | Mid-Sept | Mid-Nov | 3 | 0.10 |
| Woogenellup | 130 | Mid-Sept | Mid-Nov | 1 | 0.15 |
| Coolamon | 133 | Late Sept | Mid-late Nov | 3 | 0.00 |
| Goulburn | 141 | Late Sept | Mid-late Nov | 3 | 0.00 |
| Rosabrook | 142 | Early Oct | Late Nov | 3 | 0.15 |
*Based on proportion of hard seeds remaining at the break of season
Disease and pest resistance
Narrikup is resistant to Race 1, the most widespread race of clover scorch (Kabatiella caulivora), and to Race 2, which is prevalent on the Esperance sandplain (Table 2). No screening has been conducted for resistance levels to the other leaf diseases, powdery mildew (Oidium sp.), rust (Uromyces trifolii-repentis) or cercospora (Cercospora zebrina), but there have been no reports of Narrikup being susceptible to these diseases. Narrikup has moderate resistance to Race 177, but is susceptible to Race 173, two of the major races of the root rot pathogen Phytophthora clandestina (Table 2). Screening has not been conducted for resistance to other root rot pathogens.
Emerging seedlings of Narrikup, as with Bindoon and Rosabrook, suffer less damage from RLEM than other midseason varieties (Table 2). This is most evident at low to moderate RLEM densities, but this advantage is less at high RLEM densities. Work by CSIRO has demonstrated that RLEM fed less and produce less progeny on subterranean clovers with cotyledon resistance. Field ratings indicate trifoliate leaves of Narrikup also suffer less damage from RLEM than older varieties in winter and spring (Table 2) and have moderate susceptibility to lucerne flea. There is no information on the susceptibility of Narrikup to blue green aphid. Insecticides should be used to maximise seedling establishment and pasture production of Narrikup when RLEM, lucerne flea or aphid densities are high.
| Variety | RLEM | Lucerne flea | Clover scorch | Phytophthora root rot | |||
|---|---|---|---|---|---|---|---|
|
| Cotyledon | Trifoliate |
| Race 1 | Race 2 | Race 177 | Race 173 |
| Narrikup | 3 | 5 | 6 | 3 | 4 | 2 | 7 |
| Bindoon | 3 | 4 | 4 | 3 | 8 | 1 | 8 |
| Seaton Park | 7 | 7 | 8 | 8 | 8 | 2 | 4 |
| York | 7 | 7 | 8 | 6 | 9 | 1 | 8 |
| Campeda | 7 | 6 | 6 | 6 | 8 | 3 | 7 |
| Junee | 8 | 6 | 4 | 3 | 8 | 4 | 2 |
| Rosabrook | 3 | - | - | 2 | 4 | 1 | 2 |
Field performance
Over all sites and seasons, regenerating seedling densities of Narrikup were 27% greater than York, 61% more than Campeda, 19% more than Junee and similar to Coolamon (Table 3). These higher seedling densities and its strong early season vigour resulted in 42% greater winter biomass production than York, 87% more than Campeda, 29% more than Junee and 16% more than Coolamon (Table 3). The increased RLEM seedling tolerance of Narrikup is likely to have contributed to its excellent early season performance, which occurs at the time of greatest feed shortage. Narrikup produced 35% more biomass in spring than York and 61% more than Campeda, and had similar seed production and seed bank densities to Campeda and Coolamon (Table 3).
| Variety | Winter biomass | Spring biomass | Seed bank | Regeneration |
|---|---|---|---|---|
| Narrikup | 142 | 135 | 77 | 127 |
| Campeda | 76 | 119 | 76 | 79 |
| Coolamon | 122 | 143 | 75 | 125 |
| Junee | 110 | 137 | 109 | 107 |
| Seaton Park | 125 | 112 | 95 | 98 |
| York | 100 | 100 | 100 | 100 |
Use of Narrikup
Narrikup is suited for use on well-drained, moderately acid (pHCa 4.5 – 6.5) soils in areas of Western Australia with an annual rainfall of 500 - 700 mm, corresponding to a growing season length that extends to mid-November. It is well suited to permanent and semi-permanent pastures with occasional cropping. It is not suited to 1:1 crop/pasture rotations. Narrikup is more productive and persistent than Junee Campeda and Woogenellup and is suited to areas where these cultivars have been recommended.
Narrikup can be mixed with Bindoon in the drier part of its target zone and with Coolamon or Rosabrook in the wetter parts of its zone. Rouse or Yanco can be added to the mixture for paddocks with patches subject to waterlogging.
Narrikup should be inoculated with Group C rhizobial inoculant prior to sowing.
Seed availability and PBR status
Seed of Narrikup can be purchased through Seed Force agencies.
Narrikup is protected under the Plant Breeders Rights Act 1994. Under the Act sale of Narrikup 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.au
