Macroptilium bracteatum


Scientific name

Macroptilium bracteatum (Nees & Mart.) Marechal & Baudet

Synonyms

Phaseolus bracteatus Nees & Mart.
Phaseolus decipiens Benth.

Family/tribe

Family: Fabaceae (alt. Leguminosae) subfamily: Faboideae tribe: Phaseoleae subtribe: Phaseolinae. Also placed in: Papilionaceae.

Common names

burgundy bean.

Morphological description

Erect and trailing pubescent herbaceous perennial.  Leaves trifoliolate with stipules about 5 mm long, and pedicel ±4 cm long;  leaflets 3.4–6 cm long and 3–3.8 cm wide, pubescent on both sides;  central leaflet pandurate and the lateral leaflets with a single lobe, apex obtusePeduncle glabrous, 10–15 cm long, and with a whorl of bracts close to the base;  flowers in the upper third of the raceme, purple-red in colour with small bracts at the base of each flower;  calyx pubescent with 5 teeth.  Fruit linear , 4–9 cm long with 9–17 seeds.  Seeds almost cylindrical, 2.5–4 mm long and 3–4 mm in diameter;  brown, black or tan in colour, almost always mottled;  c. 170,000 seeds/kg.
Differs from M. atropurpureum most obviously in having a whorl of bracts at the base of the peduncle .

Distribution

Native to:
South America:  Argentina (Salta, Jujuy, Formosa), Bolivia (Santa Cruz), Brazil (Bahia, Minas Gerais, Sao Paulo), Paraguay, Peru (La Libertad), Venezuela (Anzoategui).

Uses/applications

M. bracteatum was selected for use as a short-term pasture plant on heavy textured alkaline soils in the subtropics.  It replaces the more tropically adapted butterfly pea (Clitoria ternatea ) in subtropical regions because of its greater tolerance of cooler temperatures.  It is also an alternative to lucerne (Medicago sativa ) in the subtropics.

Ecology

Soil requirements

Mostly collected from light to medium textured soils, but adapts well to heavy clays.  While the pH of these soils has most often been near neutral to alkaline, it has also been collected on soil of pH 4.5.  The key soil characteristic required for M. bracteatum is a slightly acid to alkaline soil reaction .  Despite the range of light textured soils at the point of collection, M. bracteatum was selected for use on heavy textured soils which are invariably alkaline at and near the surface.  Seed production is conducted in Queensland on moderately acid, duplex soils of granitic origin.

Moisture

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Collected in areas with annual rainfall from 400–1,600 mm but is being used in subtropical environments with summer-dominant rainfall between 600 and 1,000 mm.  Very drought tolerant and has persisted for at least 3 years on shallow clay soils with extreme mid-season droughts.

Temperature

M. bracteatum has mostly been collected between about 10 and 27°S, and up to 12°N.  It occurs at >1,200 m asl at  24°S (average annual temperature 17.5°C) to lower altitude areas with average annual temperature of 25°C.  It germinates and commences growth at lower temperatures than many other tropical and subtropical legumes.  If moisture is available, it germinates and commences regrowth some weeks earlier than C. ternatea in spring in the subtropics.  In the higher latitude subtropics where early spring rains can often occur, this is one of its most valuable characteristics.  In addition to its capacity to grow in cooler temperatures, M. bracteatum has been used successfully in pasture areas that typically have high summer temperatures (>35ºC).

Light

No information available.

Reproductive development

In the southern hemisphere, reproductive development usually commences in February after sowing in November with peak flowering in March and April, with about 50–90 days from sowing to flowering.  As with M. atropurpureum , drought conditions intensify reproductive development so that mid-season drought can result in dense flowering and potentially high seed yields.  In pastures carrying over from the previous year, flowering can commence in November and particularly if dry conditions occur mid-season, significant seed crops can develop.

Defoliation

M. bracteatum is extremely palatable and is preferentially grazed.  Consequently, grazing management in pastures with a high percentage of burgundy bean will require periods of spelling.  In the short term, individual plants have the capacity to regrow rapidly, although under longer term grazing, burgundy bean plant density  usually declines, especially when a component of a grass dominant pasture.  It is therefore essential to allow seed drop of both cultivars, but especially 'Cadarga', for burgundy bean persistence.  Although 'Juanita is strongly perennial , 'Cadarga'  is less so and relies far more upon seed production and seedling recruitment to persist.

Fire

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No information available.

Agronomy

Establishment

Burgundy bean is easily established in prepared seed beds.  Seed is relatively large and so can generally overcome soil surface crusting, a common feature of clay soils which have been cropped for several years.  Recommended depth of sowing is about 3 cm although burgundy bean does re-establish well from fallen seed that is near the surface.  Recently harvested seeds have a high level of hardseededness, although this breaks down rapidly in the soil.  Seed that has been harvested and stored should be checked for germinability prior to sowing, and, if it retains a high proportion of hard seed (e.g. >70%), should be mechanically scarified.  Seedlings can grow extremely rapidly, although they compete poorly with some weeds species and well-established grasses.  Liverseed grass (Urochloa panicoides), a common annual weed in agricultural land that has been cropped for long periods in the subtropical cropping regions of southern and central Queensland and northern New South Wales, can  seriously reduce establishment if not controlled.  Burgundy bean should be inoculated prior to sowing with a specific rhizobium strain such as CB1717 (Australia).  Recommended planting rate for uncoated seed is 2–5 kg/ha and 4–8 kg/ha for coated seed.

Fertiliser

Applications of 10–20 kg/ha P at sowing improve performance on old cropping soils.  Molybdenum and sulphur may also be necessary in some situations.

Compatibility (with other species)

Burgundy bean forms good associations with grasses adapted to clay and clay loam soils, but because of its exceptional palatability, is difficult to maintain in pastures in significant amounts after 3–4 years.  For this reason it is considered a short-term phase legume rather than a plant for permanent pastures.  The rapid growth and establishment of burgundy bean means that it can be used in combination with butterfly pea (C. ternatea ) which is comparatively low yielding in its first year but can persist for much longer.

Companion species

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Grasses:  Panicum coloratum (cv. Bambatsi), Panicum maximum (cv. Petrie), Bothriochloa insculpta (cv. Bisset), Dichanthium aristatum (cv. Floren).
Legumes:  Clitoria ternatea cv. Milgarra, Stylosanthes seabrana (cvv. Primar and Unica).

Pests and diseases

No major problems although both cultivars can show leaf symptoms of bean mosaic virus.  This appears to have little effect on productivity.  It is susceptible to bean fly (Ophiomyia phaseoli), the green vegetable bug (Nezara viridula) and a range of flower-eating caterpillars in northern Australia.  Insect control during flowering and seed set is critical in seed crops.

Ability to spread

Has the ability to spread through pod dehiscence and high seed yields but high palatability results in little spread outside of sown paddock.

Weed potential

Unlikely to have weed potential despite high seed yields.  Hard seed breaks down far more rapidly than many other tropical and subtropical legumes, and the species is very palatable at all stages of maturity.

Feeding value

Nutritive value

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While there is little information on nutritive value available, animal growth rates suggest burgundy bean produces high quality feed.  Burgundy bean has been reported to have had a leaf analysis of 3.2% N, 0.23% P and ADF of 29.3%, which was lower than that of butterfly pea but greater than for Seca stylo (Stylosanthes scabra ).  Nutritive value of burgundy bean stems at the same time were 2.0% N, 0.22% P and ADF of 37.3% which was similar to those of butterfly pea (C. ternatea ).  In another measurement of forage quality, burgundy bean 19.8% protein, less than the levels for lucerne (M. sativa ), 22% and butterfly pea 24.5%.

Palatability/acceptability

Extremely palatable and selectively grazed.

Toxicity

None recorded.  Burgundy bean does not cause bloat.

Production potential

Dry matter

In good growing conditions and in pure or nearly pure swards, M. bracteatum can produce in excess of 5–8 t/ha/yr of DM in the sub-humid subtropics.  Yields in the first year are often in this range if sufficient moisture is available.  This high first year production is a major advantage over butterfly pea (C. ternatea ) and caatinga stylo (Stylosanthes seabrana ) and lucerne (M. sativa ), all of which have considerably lower first year yields.

Animal production

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Recorded liveweight gains have ranged from 0.40–0.9 kg/hd/day.  This latter figure is from steers grazing burgundy bean dominant pastures for 71 days.  Production from a grass-burgundy bean pasture and from grass only pastures grazed for the same period were 0.85 kg/hd/day and 0.52 kg/hd/day respectively.  Annual liveweight production per unit area for burgundy bean has been recorded as between 60 and 170 kg/ha.

Genetics/breeding

Primarily self-pollinating.

Seed production

Seed maturity is not uniform and the seed pod shatters easily.  Hence direct heading is feasible but inefficient in seed recovery.  Suction harvesting is preferred.  More seed is successfully recovered by suction harvesting even though the seed (smooth, naked and oval) is not ideally suited to this collection process.  In commercial seed production, a simple, un-modified clover harvester has been used.  Seed production from the two cultivars is similar at approx. 1 t/ha with 80–90% recovered from suction harvesting.  Seed can be harvested 6–8 months after sowing.

Herbicide effects

Imazethapyr can be used as pre-sowing/pre-emergent, post-sowing/pre-emergent or post-emergent herbicide (first or second trifoliate leaf).  Pre-emergent application may have some effect on germination and post-emergent application may have some slight effect on seedlings though this is often short-term.
Glyphosate can be used post-sowing/pre-emergent to control weeds at planting.  It has also been used at low application rates on mature plants to control emerging weeds.
Herbicides used on other Macroptilium crops should be safe to use on M. bracteatum seed crops.  These include the pre-emergence herbicide, trifluralin, and the post-emergence herbicides, acifluorfen, fluazifop-butyl and sethoxydim.  Grass -selective herbicides are likely to be safe, but should be tested before broad-scale use.

Strengths

  • Suitable on a wide range of soil textures.
  • Overcomes soil fertility decline in cropping soils.
  • Germinates and grows under cooler conditions than butterfly pea.
  • Extremely palatable.
  • Regenerates well from seed each year.
  • Easily establishment on clay soils.
  • Non-bloating.

Limitations

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  • High palatability restricts use to ley and short-term phase pastures.
  • Specific rhizobium requirement.
  • Susceptible to insect and virus damage.

Other comments

  

Selected references

Clem, R.L. (2004) Animal production from legume -based pastures in Southeastern Queensland. In: Whitbread, A.M. and Pengelly, B.C. (eds) Tropical legumes for sustainable farming systems in southern Africa and Australia. ACIAR Proceedings No. 115 .
Jones, R.M., Bishop, H.G., Clem, R.L., Conway, M.J., Cook, B.G., Moore, K. and Pengelly, B.C. (2000) Measurements of nutritive value of a range of tropical legumes and their use in legume evaluation. Tropical Grasslands, 34, 78–90.
Pengelly, B.C. and Conway, M.J. (1998) The evaluation of tropical legumes for use in ley pastures in central and southern Queensland. Proceedings of the 9th Australian Agronomy Conference, Wagga Wagga. pp. 163–166.
Pengelly, B.C. and Conway, M.J. (2001) Pastures for cropping soils: which tropical pasture legume to use. Invited paper, Tropical Grassland Conference, Emerald, Queensland, April 2000. Tropical Grasslands, 34, 162–168.
Whitbread, A.M., Pengelly, B.C. and Smith, B.R. (2004) An evaluation of three tropical ley legumes and their effect on cereal production and soil nitrogen on clay soils in Queensland, Australia. Tropical Grasslands. (in press).

Internet links

Cultivars

Cultivars

Country/date released

Details

‘Cadarga’
(CPI 55769)
Australia (2000) An erect form from Brazil.  It has been consistently high yielding in the first and second years on clay soils in the sub-humid subtropics.  Although highest yielding of lines tested at most evaluation sites, it can be affected by bean mosaic virus in wet years.  It was proposed at the time of release that both ‘Cadarga’ and ‘Juanita’ be released and marketed as a composite.
‘Juanita’
(CPI 68892)
Australia (2000) A decumbent form from Minas Gerais, Brazil(19° 26'S, 890 m asl, rainfall 1,500 mm).  Relatively high yielding although not evaluated over as many sites as ‘Cadarga’.  Does not appear to be affected by bean mosaic virus, and is more persistent that ‘Cadarga’.  It was proposed at the time of release that both ‘Cadarga’ and ‘Juanita’ be released and marketed as a composite.

Promising accessions

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Promising accessions

Country

Details

CPI 27404, CPI 55756, CPI 55758, CPI 93100 Australia These accessions are similar to 'Juanita' being relatively persistent and trailing types rather than erect .  These accessions could be considered as substitutes for ‘Juanita’.