Calopogonium mucunoides Desv.

• Calopogonium orthocarpum Urb.
•  Stenolobium branchycarpum Benth.

Calopo (Australia), rabo de iguana (Colombia), falso oro (Brazil).

Vigorous, creeping and twining, hairy herb forming a tangled mass of foliage 30 to 40 cm deep. Stems succulent, covered with long brown hairs, creeping in lower part; root at nodes which come in contact with the soil; upper part of stem becomes twining. Leaves trifoliate; leaflets hairy on both surfaces, smaller than those of Pueraria phaseoloides; terminal leaflet broadly ovate to ovate-rhomboid, lateral ones are obliquely broadly ovate, about to 4 to 5 cm long and a little less in width. Stipules small and triangular; small flowers borne in short axillary racemes of four to eight to 12 on hairy peduncles. Flowers blue with greenish-yellow blotch. Pods linear, compressed, 2.5 to 4 cm long, yellowish brown, densely covered with long erect hairs, four- to eight-seeded. Seeds broadly oblong to squarish, with rounded corners, compressed, light or dark brown, not mottled, about 3.5 x 2.5 mm (Barnard, 1969).

Native to tropical South America, widely distributed as a cover crop or weed throughout the tropics.

Summer-growing perennial under wet conditions, annual seed-regenerating legume otherwise, e.g. Sri Lanka, Tanzania (Rijkebusch, 1967).

It will grow up to 2 000 m in Colombia (Crowder, 1960) but prefers low elevations.

Generally at least 1 125 mm and preferably more than this.

May die out under dry conditions and regenerate in the wet season as an annual form seed, or simply drop its leaves, depending on the intensity of the dry season.

Excellent. Grows in very wet conditions in Fiji, Panama and Venezuela, and nodulates well.

Adapts to a wide range of soil textures and pH, doing quite well at pH 4.5 to 5.0.

Unspecialized in its Rhizobium requirement. If inoculating, use cowpea-type, e.g. CB 756 (Norris, 1967).

Excellent in moist fertile situations, where it has a tendency to become a weed. Seed is also spread by birds (Horrell, personal communication) .

Usually sown on well-prepared seed bed for use as cover crop. For pasture purposes, would establish easily on a roughly prepared seed bed.

Usually drilled or broadcast; can be broadcast on ground or from air into the ashes after a burn. Oversown into natural pastures under wet moist conditions, it should establish well. Could also be sod-seeded.

Sown at 1 to 2.5 cm and lightly covered with harrow, or sown in ashes of a burn.

Midsummer, at 1 to 2 kg./ ha. Number of seeds per kg. 65 000 to 70 000.

Otero (1952) gives 75 percent hard seed in a fresh sample, of which 13 percent germinated and 12 percent was rejected seed.

To break dormancy: (a) treat with concentrated sulphuric acid (sp. gr. 1.8) for 20 min. (Prodonoff, 1968) or with 24 or 36 N sulphuric acid for seven minutes, wash and dry (Black, 1968); (b) scarify with sand (Otero, 1952, obtained 99 percent germination); (c) infra-red irradiation­Philips Infraphil lamp 13373/479 (150 watts) for eight hours or Osram I.R.R. 4892 (250 watts) for 16 hours (Wycherley, 1960). Inoculation not necessary, but preferable. Pelleting not necessary unless to protect rhizobia when rock phosphate should be used (Norris, 1967). Insect and disease control usually not necessary.

Usually gives marked response in leaf size to application of superphosphate.

Excellent. Grows with all the tall tropical grasses such as Panicum, Hyparrhenia, Setaria, Brachiaria and Melinis, and persists with pangola grass if carefully grazed. Often sown with centro and puero in green manure mixtures to give early cover, after which puero and then centro persist.

No data available.

Vigorous seedling enables rapid early growth.

A most vigorous plant giving a full 7 over in 4 to 5 months (Crowder, 1960). At Sigatoka, Fiji, it was the only legume making a contribution to the fodder six weeks from sowing (Payne et al., 1955).

Oke (1967b) rated it as less than that of puero. It fixed 3.8 mg N/day per plant and 87 percent of the fixed N was transferred to the tops. In wet conditions in Panama, it nodulates well and provides a good deal of nitrogen to associated pangola grass early in the life of the mixture, but does not persist with pangola grass in Colombia. Schofield (1945) found that the nitrogen content of soil previously under bare fallow at Innisfail in north Queensland, Australia, for seven months was 34.4 ppm. In soil into which calopo had been ploughed, after 18 months' growth it was 66.7 ppm compared with 171.8 ppm under puero, which was the highest of four legumes.

Recovers slowly. Crowder (1960) states that it can be cut at eight-week intervals in Colombia.

Grazing should not begin until the plants begin to grow erect; then rotationally at intervals of 8 to 12 weeks.

Will not tolerate fire, but regenerates from seed.

Probably self-fertile. Chromosome number 2n = 36.

Crowder (1960) recorded 4 tonnes DM/ha in Colombia; van Rensburg (1967) 3 067 kg./ha in Zambia.

Not usually conserved for hay. No record of its use as silage.

Will persist in frost-free moist localities. It remained green and continued to produce some growth in the dry season in Zambia (van Rensburg, 1967). At Parada in north Queensland (Downes, 1966) and at Serere, Uganda, it dropped its leaves and gave poor standover feed.

• Chemical analysis and digestibility: 

Bermudez et al. (1968) recorded 16.7 percent crude protein in the dry matter. Vergara (1967) recorded an average phosphorus content of 0.25 percent and 1 percent calcium in dry matter.

• Palatability:

Although calopo is generally recorded as unpalatable, the author has seen a paddock of P. maximum, centro and calopo pasture well grazed by dairy cattle near Mombasa, Kenya. Lychatchynsky and Steenmeyer (1968, unpublished) tested several legumes at Matão, São Paulo, Brazil, for palatability, including glycine, siratro, the desmodiums, lotononis and teramnus. Calopo was low in palatability early, but after flowering it became most palatable and, at the rating given it, it proved the most palatable overall. It would appear that some strains are more palatable than others. Bermudez et al. (1968) says it is not palatable because of its hairiness. It is eaten well in pastures at Palmira and Turipana, Colombia, and Serere, Uganda (Horrell, 1958).

None observed.

Much by hand; some directly with an all-crop harvester.

Seeds well in Brazil; van Rensburg (1967) stated that it was a shy seeder in Zambia. Average yield 200 to 300 kg./ha (Davies and Hutton, 1970).

None recognized commercially.

Attacked by virus in Guatemala, Costa Rica and Panama.

Vigorous early growth covers the ground well as a pioneer legume in scrub burns; easy establishment; effective nodulation and tolerance of wet conditions; builds up a lot of leaf mulch.

Relative unpalatability, short life and intolerance of dry conditions.

Was combined with Para grass in pastures in north Queensland but proved unpalatable and was discarded. Provides useful pasture with guinea grass and centro on Kilifi plantation near Mombasa, Kenya, and with a number of species in Colombia, but here Neonotonia wightii is the preferred species.

Schofield (1941).

Adapted to the hotter, wetter tropics.

Not as cold-hardy as centro or puero . Ludlow and Wilson (1970) obtained only 2 percent of the dry matter, 4.8 percent of the growth rate and 14 percent of the leaf area when grown at 20°C compared with the growth at 30°C. This was the poorest performance of the tropical legumes tested.

None.

Occurs from Mexico to northern Argentina (Burkart, 1952)­ southern limit at about lat. 29 to 30°S. Some native Calopogonium species are listed by Burkart in Argentina.

Can grow in reduced light conditions with tall grasses and is used as a cover in plantation crops; but Schofield (1941) states that it is shade-intolerant .

Excellent; quickly suppresses weeds and in some cases becomes a weed itself.

Fifty percent germination and 93.5 percent purity, with maximum hard seed content of 10 percent in Queensland. Germinated at 25°C (Prodonoff, 1968).

Subject to attacks by leaf-eating caterpillars and beetles, but generally not affected in growth.