Lucerne

Medicago sativa L.

Family: Fabaceae.

Names:

Medic is from the Latin medica meaning Lucerne and derived from the Greek mediche because it was introduced to Greece from the Media region in the Old Persian Empire.
Sativa is Latin for sown or planted referring to it as the cultivated form.
Lucerne

Other names:

Alfalfa

Summary:

A semi erect, shrub like, fast growing, palatable, perennial legume to 90 cm tall with trifoliate leaves and spikes of purple, pea type flowers in spring to summer.

Description:

Cotyledons:

Two. Oval to club shaped. Tip rounded. Base tapered. Hairless. Short petiole.

First leaves:

First leaf is round, oval, kidney or spade shaped. Edges slightly toothed. Tip pointed but appears indented. Base slightly indented. Hairs on back of leaf
Petiole - Long. Hairy.
Stipules - Long and toothed.
Second and subsequent leaves similar to adult leaves

Leaves:

Set of 3 leaflets on short stalks. The stalk of the centre leaflet is slightly longer than those of the side leaflets.
Stipules - Narrowly egg shaped, 4-10 mm long. Taper to a pointed tip. Edges smooth or with small teeth or wavy or no teeth. Attached to petiole.
Petiole - Long, but short on flowering shoots. Hairy.
Blade - Of leaflet, egg shaped, oval or oblong. 10-30 mm long x 5-12 mm wide. Small teeth on the edges of the upper third. Tip notched or with a short sharp flexible point. Veins branched. Hairy.

Stems:

Sprawling or erect. Up to 900 mm long. Soft, sparse, tiny, multicellular hairs. Square towards the top.

Flower head:

Oblong, dense axillary raceme, 15-60 mm long. Many (20-30) flowers on stalks, 25-50 mm long. Arise from the upper leaf axils.

Flowers:

Pea type, purple or blue, 8-15 mm long.
Bracts - Small, persistent.
Ovary -
Calyx - Tubular with 5 lobes. Tube is hairy and 2-3 mm long with tapering, awl shaped lobes that are 2.5-4 mm long. Hairy.
Petals - Violet or purple. Standard 8-12 mm long x 3-5 mm wide. Limb is egg shaped. Wings 5-8 mm long. Keel 5-8 mm long.
Stamens - 9 in a group and 1 alone.
Anthers -

Fruit:

Pod with 2-5, loose coils, with anticlockwise spiral. open through the centre, 3-6 mm diameter x 4-8 mm tall, smooth, and no spines. Sparsely hairy. 2-6 seeds per pod. Net like veins on the surface.

Seeds:

2-2.5 mm long x 1-1.2 mm thick, kidney shaped. Cream to yellow brown.

Roots:

Long, deep taproot and many laterals. Nitrogen fixing nodules.

Key Characters:

Cotyledons oval to club shaped.
First leaf round, oval, kidney or spade shaped.
Older leaves trifoliate with the terminal leaflet on a longer petiolule than the side leaflets.
Stems square towards the top.
Purple or blue pea type flowers.
Spirally coiled pod with an opening through the centre, several seeds and pods without spines or tubercles, the transverse nerves running from the ventral to the dorsal suture without the intervention of any nerves parallel to the dorsal suture.
Seed kidney shaped.
Perennial.

Agronomy:

Choose soils that are >1 m deep, well drained, pH(CaCl) > 5.2. Avoid deep white sands (eg Badgingarra sands), Wodgil soils and non wetting soils.
If pH(CaCl) is less than 5.2 apply lime several years before sowing or incorporate before sowing.
Inoculate seed with Group AL inoculum and lime pellet seed within 48 hours of planting.
Use a seeding rate of 2-3 kg/ha in the 250-450 mm rainfall zone and 4-5 kg/ha in higher rainfall zones.
Plant dry land varieties from May to August. Use the earlier times in lower rainfall areas. June and July plantings are slow growing and require better weed and insect control. Sow as a pure stand or as alternate rows with a grain crop.
Sow seed 5-10 mm deep into moist soil to prevent inoculation failure. Ensure good seed-soil contact. Press wheels are preferred. Some rotary harrows bury seed too deep. Precision sowing tined implements (ConservaPak, DBS, Nichols) are best followed by Precision sowing disk implements (Biomax, Great Plains, K-Hart, Walker) then Knife points with press wheels at slow speed and set less than 40 mm deep. Full cut points and culti-trash machines usually place the seed too deep - for these machines cultivate first then spread seed and incorporate with harrows before the soil dries out.
Apply trifluralin pre plant in areas prone to grasses or Wireweed.
Use methidathion immediately post plant if Redlegged Earth Mite and Lucerne Flea are present. Aphids may be a problem in some varieties in some seasons.
Poor weed and insect control are common causes of failure.
Once established, grazing can usually be used to minimise losses from insect attack.
Pink Cutworm, Lucerne Leafroller, Sitona Weevil, Small Lucerne Weevil and Wingless Grasshoppers are the major pests of Lucerne.
Overgrazing may cause Crown and Root rots. Other diseases are usually controlled by grazing or mowing and removing infested material.
Alfalfa Mosaic virus is the most common viral disease and can be reduced by planting healthy seed and keeping aphids under control to prevent spread of the disease.
Lucerne requires 9-12 kg/ha/year of phosphorous or 100-120 kg/ha superphosphate. It also has a greater requirement for potash than the cereals. Fertilise with Potash if hay is being taken from the paddock or if soil tests are below 70-100 ppm. Broadcast 15-20 kg/ha Potash (30-40 kg/ha Muriate of Potash) before planting in deficient areas. Don't apply Potash fertiliser close to seed as it can be toxic.
Being a legume, Lucerne produces its own nitrogen.
Hay baling is best done at night or early morning to reduce loss of leaf material.
Lucerne makes good stock feed with crude protein of 19-29%, metabolisable energy of 9-12 MJ/kg and digestibility of 66-76%.
Rotational grazing is preferred for sheep to reduce selective grazing. Grazing with 2-4 times the normal stocking rate for 1-3 weeks at a time is preferred on dry land stands.
Cattle can be continuously grazed but generally with lower growth than good green pasture. Sudden death from bloat can be a problem on pure stands. Vaccinate cattle for pulpy kidney before grazing Lucerne. Provide access to hay. Graze continuously rather than in rotation. Use sheep for winter spring grazing and cattle in summer autumn. Avoid succulent stands with cattle (flowering and mature stands have less bloat risk).
Bloat can occur in sheep but is not common on dryland stands.
Pulpy kidney can be a problem in both sheep and cattle and stock should be vaccinated.
Red Gut is an minor problem and can usually be overcome by providing alternate feed or cereal hay.
Fertility problems due to high oestrogen levels can occasionally occur.
Pizzle rot may be a problem in wethers.

Biology:

Life cycle:

Perennial. Germinates from autumn to spring. Flowers October to February.

Physiology:

Varieties tolerant to grazing, drought, and diseases and with increased winter growth have been bred.
Does not tolerate waterlogging.
Moderate tolerance of salinity in well drained areas. A 50% loss in production can be expected on soils with a soil conductivity of 9 mS/cm and a 20% loss at 4 mS/cm.

Reproduction:

By seeds.

Flowering times:

Summer to autumn in western NSW.
Flowers in summer in SA.
October to February in Perth.
Late spring and summer in WA.

Seed Biology and Germination:

Vegetative Propagules:

Perennial crown.

Hybrids:

Many varieties have been bred.
Winter dormant varieties are best suited to irrigation areas.
Semi winter dormant varieties are suited to dry land situations where there is a shallow fresh water table or subsoil moisture during summer or in summer rainfall areas.
Winter active and highly winter active varieties are best suited to dry land situations where it will be rotated to grain crops every 3-5 years.

Allelopathy:

Population Dynamics and Dispersal:

Spread mainly by intentional planting and seed dispersal.

Origin and History:

Southern Russia. Western Asia. Eastern Turkey. Iran.

Distribution:

ACT, NSW, QLD, SA, TAS, VIC, WA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Temperate. Mediterranean. Requires at least 250 mm annual rainfall to persist and is not usually profitable where the rainfall is less than 320 mm.

Soil:

Most common on loams, sands and red brown earths. Prefers well drained soils that are more than one metre deep and are not prone of waterlogging.
Tolerates pH(CaCl) 4.8-8.

Plant Associations:

Significance:

Beneficial:

Cultivated for fodder and seed.
Produces a large bulk of palatable feed.
Cut for hay at early flowering and several times during the season.
Honey plant.

Detrimental:

Weed of roadsides, disturbed areas, cultivated areas and other crops.
Taints milk and meat.

Toxicity:

May cause bloat in cattle and sheep.
Causes red gut in sheep.
Occasionally toxic causing photo sensitisation referred to as trefoil dermatitis, clover sickness or trifoliosis in sheep, cattle, horses and pigs (especially young white pigs). Lambs including newly born ones are most affected. Mainly occurs on luxuriant growth during sunny weather in spring.
May cause oestrogenic effects in stock.
May cause pulmonary disease.
Causes urine discolouration in cattle.
May contain toxic amounts of nitrate.
Associated with hay fever and asthma.
May cause oestrogenic effects or "clover disease" in livestock.

Symptoms:

Dermatitis with no jaundice. Rarely fatal.
Bloat.
Red gut - Isolation, depression, lay down with nose on the ground, sudden death. Occurs in warm, dry conditions often after light rain on pure lucerne stands.
Clover disease - Reduced fertility, difficult birth and prolapse of the uterus in ewes. Urinary obstruction and milk production in wethers.

Treatment:

Remove stock from pure stands or supply alternative feed.

Legislation:

None.

Management and Control:

Control Lucerne in the spring before planting winter crops to allow time for nitrogen to be released. A sprayed lucerne pasture will release about 0.5 kg of N for each mm of summer rainfall. (562)

Thresholds:

Eradication strategies:

It is difficult to kill. Picloram, dicamba and metsulfuron provide the best control.

Herbicide resistance:

It is relatively tolerant to glyphosate, paraquat and diquat.

Biological Control:

Related plants:

Barrel Medic. (M. truncatula)
Black Medic (M. lupulina)
Burr Medic (M. polymorpha)
Button Medic (M. orbicularis)
Calvary Medic (M. intertexta)
Cutleaf Medic (M. laciniata)
Disc Medic (M. tornata)
Gama Medic (M. rugosa)
Lucerne (M. falcata ssp. sativa)
Lucerne (M. sativa)
Small leaved Burr Medic (M. praecox)
Snail Medic (M. scutellata)
Spotted Medic (M. arabica)
Strand Medic (M. littoralis)
Woolly Burr Medic(M. minima)
Yellow Lucerne (M. falcata)

Plants of similar appearance:

Clovers (Trifolium species) usually have the central leaflet on a stalk that the same length as the stalks on the side leaflets.
Melilotus species are very similar in the vegetative stage but generally have a strong odour when crushed and are often annual or biennial and have yellow flowers.
Oxalis species usually have a bitter taste.
Trefoils

References:

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P458. Diagram.

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P223. Diagram of pod.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P404. Photo.

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P470-472, 490.

Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P154. Photo.

Hyde-Wyatt, B.H. and Morris, D.I. (1975). Tasmanian weed handbook. (Tasmanian Department of Agriculture, Hobart, Tasmania). P104. Diagram of leaf and stipule.

Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #806.15.

Marchant, N.G., Wheeler, J.R., Rye, B.L., Bennett, E.M., Lander, N.S. and Macfarlane, T.D. (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P284.

McBarron, E.J. (1983). Poisonous plants. (Inkata Press, Melbourne). P80-81. Diagrams.

Moerkerk, M.R. and Barnett, A.G. (1998). More Crop Weeds. R.G. and F.J. Richardson, Melbourne. P90. Diagrams. Photos.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.