Narrikup subterranean clover

Page last updated: Tuesday, 13 August 2019 - 9:47am

Narrikup is a very vigorous midseason flowering variety of the “black-seeded” subterraneum subspecies of sub clover. It is best suited to well-drained, moderately acidic (pHCa 4.5 - 6.5) soils in areas with 500 - 700 mm mean annual rainfall and where the growing season extends to mid-November. Its particular strength is its high winter production, driven by strong seedling regeneration densities and its seedling resistance to redlegged earth mites (RLEM). Narrikup also has resistance to both known races of clover scorch, caused by Kabatiella caulivora.

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.

Table 1 Major agronomic characters of Narrikup and other midseason varieties

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.

Table 2 Pest and disease resistance ratings (0-10) of Narrikup and other varieties, where 0 = very resistant, 10 = very susceptible

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).

Table 3 Winter and spring biomass production, seed bank and seedling regeneration densities of Narrikup and other varieties averaged over three seasons at six high rainfall sites across southern Australia (expressed as a percent of values for cv. York)

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

Seed Force

Contact information

Paul Sanford
+61 (0)8 9892 8475

Author

Phil Nichols