Hybrid disc medic

Hybrid disc medic

Hybrid disc medic
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NOTE: The information in this Agnote must be read in conjunction with Introduction to selecting and using pastures in NSW, which covers information on areas of adaptation, sources of variability, species mixtures, and important issues related to animal health and the conservation of native vegetation.
Pasture type and use Early-maturing, annual, temperate legume for dryland grazing and crop rotation.
Area of adaptation South-west NSW
Min. average annual rainfall 275 mm
Advantages
  • Provides high herbage and seed production.
  • Good bluegreen aphid resistance.
  • Low to moderate resistance to spotted alfalfa aphid.
  • On sandhills, performs better than Herald * (strand medic variety).
  • Matures early to set seed before season ends. Good for building soil nitrogen level for following cereal crops.
  • Sufficiently hard-seeded to allow persistence through cropping phase and up to 2 years depending on soil seed reserves.

* Denotes that this variety is protected by Plant Breeder’s Rights.

Disadvantages
  • Possibly a host for root lesion nematode.
Soil requirements Recommended for neutral to alkaline, sandy to loamy soils, especially in mallee dune–swale situations.
Varieties Toreador*

*Denotes that this variety is protected by Plant Breeder’s Rights.

Sowing rates:
  • 5–8 kg/ha
  • in mixtures - 3–4 kg/ha
Sowing time Autumn
Companion species On sandy soils, strand medics (e.g. variety Herald* ).
On loams, barrel medics (e.g. variety Caliph * ).
In variable paddocks, consider a mixture of all three varieties.
Inoculation Inoculation is vital where there is no previous medic history and where pH < 7 in water or calcium chloride. Use group AL. (Note: Do not use group AM.)
Major nutrient deficiencies Requires adequate levels of available phosphorus. Sulfur and zinc levels should also be monitored.
Main insect pests Redlegged earth mite (attacks seedlings).

Bluegreen aphid and spotted alfalfa aphid. (Toreador * has resistance to bluegreen aphid, but it is still necessary to monitor for large populations.)

Lucerne flea.

Occasionally sitona weevil and brown pasture loopers.

Main diseases Root fungus, Rhizoctonia spp.
Black stem fungus, Phoma spp.
Root lesion nematode, Pratylenchus neglectus.
Management Sow in mid-autumn and check seedlings regularly for redlegged earth mite.

Do not graze until well established. For maximum seed yields, restrict grazing during flowering and seed maturation. When grazing sheep over summer, use light stocking rates to avoid too much seed pod being removed.

Must manage so that seed reserves are maximised in the first year.

Livestock disorders of particular note Can cause bloat in cattle.
Additional tips
  • Spray-topping annual grasses at seed-set in spring can severely reduce the seed production of medics.
  • For newly establishing medic pastures (not undersown to cereals), removal of grass weeds with grass selective herbicides can give better seed yields by reducing competition.

Acknowledgments

Advice on livestock health disorders was provided by Dr Chris Bourke, Principal Research Scientist, NSW Agriculture, Orange. Valuable comments on the script were provided by J. Howie, Senior Research Officer, South Australian Research and Development Institute. Their contribution is gratefully acknowledged.

Photo: Mary-Anne Lattimore, NSW Agriculture, Yanco.