Macroptilium lathyroides (L.) Urb.

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Phaseolus lathyroides L. Phaseolus semi-erectus (L.) DC, P. crotalaroides Mort.

Common names

Phasey bean, Murray phasey bean (Australia), frijol de monte (Venezuela), frijol de los arrozales (Colombia), wild pea bean (Hawaii) .


Herbaceous annual or short-lived perennial, erectly branching, 0.5 to 1 m high under normal conditions, lower parts becoming somewhat woody; when grown under shade, in association with tall grasses or sown early, assumes a twining habit and may attain 1.2 m. Branches terete, clothed with long deciduous reflexed hairs. Leaflets ovate or lanceolate, 3.5 to 7.5 cm long. Inflorescence, semierect racemes about 15 cm long borne on axillary peduncles up to 25 cm; pedicels short. Flowers red-purple. Pods subcylindrical, 7.5 to 10 cm long and 3 mm wide, slightly curved, approximately 20-seeded. Seeds oblong or rhomboidal, slightly compressed, about 3 mm long, mottled light and dark grey-brown (Barnard, 1967). It regenerates from seed under favourable conditions but Bryan (1968a) found that it was unreliable in this regard at Beerwah, south-east Queensland.


Originated in tropical America and is now widespread and naturalized in the tropics, including Colombia, Venezuela, Paraguay, Belize, Panama, Brazil, the Caribbean (Jamaica, Antigua, St. Vincent, Cuba) and Australia.

Altitude range

It grows from sea level to 1 800 m in Colombia (Crowder, 1960).

Rainfall requirements

It is adapted to a wide range of climates with a rainfall from 475 to 3 000 mm, although insect damage may be severe in the higher rainfall regime and its growth will depend on summer storms and wetter depressions in the lower rainfall areas.

Soil requirements

Phasey bean is adapted to a wide range of soils, from deep sands to heavy clays, including lateritic types. It tolerates both acid and alkaline soils. It is fairly tolerant to saline conditions (Fretes, Samudio and Gay, 1970).

Rhizobium relationships

Nodulates freely with native rhizobia. If inoculation is desired, use the cowpea strain, the current Australian recommendation being CB 756 (Date, 1969) and, in Argentina, strains C5 (from the United States) and 95 (of Australian origin) (Batthyany, 1970).

Ability to spread naturally

Under moist conditions, it will spread well naturally in both sandy and clay soils if competition is not too severe.

Land preparation for establishment

Phasey bean grows best on well-prepared seed beds but will give less satisfactory establishment with less cultivation.

Sowing methods

Seed can be drilled, or broadcast from the ground or from the air. In the poorly drained flood-plain soils of the Burdekin River in north Queensland, Seton (1962) suggested that phasey bean seed should be drilled into the top of planting ridges (15 cm high and 1 m apart) and vegetative grass material (e.g. Para grass, planted two to three months later) between these ridges. Irrigation water is then applied between the ridges so that the legume seed is moistened only. Oversowing into natural pastures is usually not very successful. It can be sown at any time during spring and summer when moisture is adequate, using 1 to 3 kg. seed/ha. Sow on the surface or no deeper than 1.25 cm and cover lightly with a harrow.

Number of seeds per kg.

119 000 (ranging from 88 000 to 154 000). Percentage of hard seed is fairly low.

Seed treatment before planting

To break dormancy, treat the seed with concentrated sulphuric acid (sg. gr. 1.8) for 20 minutes, wash and dry (Prodonoff, 1968). Inoculation is not necessary. Pelleting is not necessary unless to protect the rhizobia (use rock phosphate; Norris, 1967). For insect and disease control, treat the seed with 2.2 g acid equivalent (13.2 ml of 15 percent emulsifiable concentrate) of dieldrin per kg. of seed before planting to control bean-fly damage to seedlings (Jones, 1965).

Nutrient requirements

On fertile alluvial soils or heavy clays, it need not be fertilized. On poor sandy soils, use 250 kg./ha molybdenized superphosphate. On lateritic gravels in Sri Lanka, Paltridge and Santhirasegaram (1957) found responses to Ca, N, P and K, and on cinnamon sand to P, Ca, Mg, K and B.

  • Calcium: 

Macroptilium lathyroides gave 68 percent of its maximum yield in the absence of calcium, and its maximum yield at 995 kg./ha. In the absence of calcium, N, P and K had an adverse effect on its root growth. It responded to lime by increasing its nitrogen content from 1.7 percent with nil to 3.8 percent with 740 kg./ha calcium carbonate (Andrew and Norris, 1961). Paltridge and Santhirasegaram (1957) found small responses to lime on lateritic gravels and sand in Sri Lanka. The calcium uptake by phasey bean was found by Andrew and Hegarty (1969) to be 1.5 to 1.9 percent of the dry matter.

  • Copper: 

Phasey bean gave 46 percent of its maximum yield in the absence of copper, and so is relatively insensitive to low copper status in the soil. Copper concentration in the plant was relatively high, being higher in the roots than in the tops (Andrew and Thorne, 1962). Santhirasegaram (1967) recorded 57 percent of the maximum yield in the absence of copper in a sandy soil in Sri Lanka. Copper deficiency in this species does not show specific symptoms. It causes reduced plant growth, with a slight change in colour of the younger portions of the plant from the natural mid-green or greyish-green, to pale green. Progressively, these portions become yellowish green and the younger, fully expanded leaves absciss. The leaf abscission is not preceded by interveinal chlorosis or any form of necrosis. Immediately prior to abscission, the leaves tended to fold down against the stem of the plant, the condition resembling partial wilting. In severe cases, after several leaves had dropped, the growing shoots became necrotic and the plant commenced axillary growth, which also became necrotic (Andrew, 1963).

  • Molybdenum: 

't Mannetje, Shaw and Elich (1963) found that phasey bean responded to molybdenum and that the molybdenum had a residual effect in the soil for three to four years. Santhirasegaram (1967) also obtained a response to molybdenum on sandy soils in Sri Lanka.

  • Phosphorus: 

Phasey bean gave 55 percent of its maximum yield at 250 kg./ ha superphosphate, with its maximum at 1 132 kg./ha. The critical percentage of phosphorus in the dry matter of the leaves was determined by Andrew and Robins (1969a) as 0.20 percent. Increasing phosphorus supply in the form of monocalcium phosphate increased the magnesium content but decreased the potassium content.

  • Potassium: 

Santhirasegaram (1967) obtained 50 percent of the yield of phasey bean at first harvest and only 12 and 4 percent at the second and third harvest when potash was eliminated­compared with the yields from a complete fertilizer mixture. Andrew and Robins (1969c) found the critical percentage for potassium in the dry matter of the tops to be 0.75 percent. It gave only 24 percent of its maximum yield in the absence of potash. Added potassium had little effect on the concentration of other cations. Andrew and Pieters (1970a) showed that deficiency symptoms commenced on lower leaves as a rust-coloured spotting on the upper surfaces of the leaflets. Individual spots were asymmetrical in shape and mostly interveinally placed toward the margins of the leaflets. In this phase, there were no signs of blemish or discoloration on the lower leaf surfaces, nor was there any associated chlorosis or necrosis. With increased severity, the rust-coloured areas became necrotic with light brownish-grey centres and dark brown peripheries. Necrosis was evident on both surfaces of the leaflet, but, in addition, the lower surface of the leaflet was sunken at the necrotic areas. Following this phase, there was a general marginal interveinal chlorosis of the lower leaves, but a halo of green tissue remained around the necrotic spots. Chlorosis intensified, followed by necrosis of the leaflet margin, particularly toward the distal end of the leaflets. Finally, severely affected leaflets abscissed, the central leaflet of each leaf falling before the lateral ones, resulting in an upright, single-stemmed plant, abscissed leaves in the lower portion, necrotic interveinally chlorotic leaves in the central portion, and an otherwise normal top portion with reduced growth rate. The authors found the healthy plant to have 1 g/100 g potash in the dry matter of the tops. In the deficient plant, the concentration was 0.57 g/100 kg.

  • Sulphur: 

Santhirasegaram (1967) recorded only 28 percent of the yield of phasey bean growing on sandy soils in Sri Lanka compared with the yields obtained from a complete fertilizer.

  • Zinc: 

Russell (1966) found that the yields of phasey bean growing on a solodic soil in south-east Queensland were severely depressed by liming above pH 6.3 in the absence of zinc; the addition of zinc gave small yield increases.

Compatibility with grasses and other legumes

Compatible with Para grass (Brachiaria mutica) under swampy conditions; on well-drained land it grows well with Panicum maximum, Setaria anceps and Paspalum commersonii.

Tolerance to herbicides

No record.

Nitrogen-fixing ability

Paltridge (1955) analysed its effect on a companion grass, Paspalum commersonii, at Lawes, Queensland (lat. 27°30'S), growing in a heavy black clay soil. Grown as a sward, the legume increased the yield over grass plus 100 kg. N/ha by 77 percent. In terms of the total yield of nitrogen, Paltridge estimated that the inclusion of phasey bean into P. commersonii would be the equivalent of adding 800 kg./ha sulphate of ammonia.
Sen and Paul (1959) found that the nitrogen content of the soil after three years' growth of phasey bean was the same in the first 30 cm of the profile and had increased 10 and 15 percent respectively in the 60- and 90-cm zone. No fertilizer data were given.ğ

Response to defoliation

Paltridge (1955) found that-M. lathyroides did not persist with continuous grazing. Heavy grazing including woody parts severely reduces its vitality.

Grazing management

It should only be lightly grazed to encourage persistence. Only leaves and fruiting branches should be removed by the grazing animal. Paltridge (1955) found that it should be rested for six to eight weeks during the summer growing season, as it is selectively grazed early in the growing period. A light cultivation of the pasture helps annual regeneration.

Response to fire

Does not survive fire, but the seed will germinate afterwards when conditions are suitable.

Breeding system

It is closely self-pollinated (Hutton and Beall ,1957) . A relative humidity of 95 percent or more at 28°C was necessary for vigorous pollen germination and pollen tube growth. The flowers do not "trip". Temperatures between 23 and 30°C are satisfactory (Hutton, 1960).d a

Dry-matter and green-matter yields

Paltridge (1955) obtained a mean yield of 5 439 kg. DM/ha from a mixed pasture of M. lathyroides with Paspalum commersonii and 4 115 kg./ha from the grass alone. Crowder (1960), in Colombia, recorded a production of 15 tonnes/ha of green material when cut at a height of 1.25 to 1.5 m.

Suitability for hay and silage

Makes quite good hay if an effort is made to conserve the leaf, handling the material when it is supple. Robertson (1971) made excellent silage with Sorghum almum mixed with phasey bean in Uruguay and fed it successfully to Brahman cows and calves.

Value as a standover or deferred feed

It contributes very little to winter feed, as it is susceptible to frost and defoliates after frosting.

Feeding value

Has a high feeding value, which declines after frosting.

  • Chemical analysis: 

Milford (1967) determined the analyses for phasey bean shown in Table 14.6.

  • Digestibility: 

The mean intake of 19.6 g/kg. W0 75 was higher than the autumn means for subtropical grasses. The highest intake was before leaf shedding and intake fell by 37 percent after frosting.

  • Palatability: 

Stock prefer to graze M. lathyroides after the seed has set; young plants appear to be less palatable (Young, Fox and Burns, 1959).


It had been reported as poisonous to horses, but Paltridge (1955) found no toxicity with horses at Lawes and chaffed green material had no effect on dairy cows when fed for ten successive days. It did not produce any milk taint.

Seed harvesting methods

Its shattering habit makes it difficult to obtain full seed yield. It can be direct-headed when a fair percentage of the pods are ripe to ripening and the material subsequently dried where seed from dehiscing pods will not be lost. Subsequent threshing in a stationary thresher and winnowing to clean the seed are required. Seed yield. Two hundred to 250 kg./ha.


There is only one cultivar, cv. Murray, which is more robust and vigorous than other ecotypes so far tested. Some more prostrate new ecotypes are under test.


Susceptible to Phaseolus virus 2 (Wilson, 1958). Shows field resistance to little-leaf (Hutton and Grylls, 1956).

Main attributes

An excellent pioneer species giving rapid growth, nitrogen fixation and early feed in pasture mixtures in the establishment year. Can be grazed without damage to the permanent legumes, which helps in early weed control (Bryan, 1968a). Is adaptable to wet conditions and to poor soils. Seeds heavily. Andrew (1964) has found it particularly suitable as an indicator plant in nutrition studies.

Main deficiencies

It is only an annual or biennial and does not persist in pastures at Beerwah, south-eastern Queensland (Bryan, 1968a). Is susceptible to bean-fly and nematode attack. Because of seed shattering, it is difficult to obtain an effective seed harvest.


It has not been widely tested as a major constituent of tropical pastures. Bryan (1968a) and Ebersohn (1969) stressed its value as a pioneer species to give an early return on the capital invested in pasture improvement. At Rodd's Bay (central Queensland), Bryan and Shaw (1964) obtained a live-weight gain of 404 kg./head and 90 kg./ha on Paspalum plicatulum/ phasey bean pastures in 7/2 months of grazing in the first year, stocked at 1 beast/1.8 ha. The yield from native pasture alone was 185 kg./head and 19 kg./ ha stocked at 1 beast/4 ha.
Young, Fox and Burns (1959) found that it produced up to 495 kg. DM/ha in the second autumn in a grass/legume mixture at Gayndah, south-east Queensland, and produced high-quality fodder in late autumn. However, it did not persist longer than two years and gave no winter grazing because of defoliation by frost.

Main reference

Paltridge (1955).

Latitudinal limits

About 23°N to 28°S.>

Ability to compete with weeds

It competes favourably with weeds under fertile, moist conditions.


Seedlings are severely attacked by bean fly (Melanagromyza phaseoli). Nematodes attack the roots in sandy soils, the main species being Meloidogyne incognita (Koford and White) Chitwood.

Toxicity levels and symptoms

Manganese­phasey bean is subject to manganese toxicity in high manganese soils. Andrew and Pieters (1970b) showed that the first sign of toxicity in this species was a light interveinal chlorosis of the growing shoots. With increasing severity, these leaves upon expansion continued to show the interveinal chlorosis effect, but new shoots were more severely chlorotic. As toxicity progressed, leaflets moderately affected by chlorosis also showed brown necrotic areas at the extremities of, and along, the secondary veins; these brown areas appeared to be more developed on the underside of the leaflets than on the upper side. Associated with this effect, the younger shoots were severely chlorotic and when fully expanded showed puckering of the leaflet surface, usually raised above the upper surface. In addition, the necrotic spots at the vein tips coalesced, and those that affected leaflets showed edge and tip necrosis with outward and downward curling of the leaflet lamina, while the base of the leaflets remained interveinally chlorotic with some brown necrotic spots along the veins. In the severe form, new shoots were almost devoid of chlorophyll, were puckered and malformed, and abscissed prematurely, while brown necrotic patches occurred on the stems and petioles. Axillary growth followed this phase but it was also chlorotic upon emergence . Aluminium­Russell (1966) reported aluminium toxicity in Macroptilium lathyroides growing on a solodic soil of low calcium status in south-eastern Queensland. By adding lime he was able to eliminate the toxicity.P

Temperature for growth

Whiteman (1968) found that the optimum temperature for growth was 30/25°C. Minimum temperature was not recorded. It is susceptible to frost, but has usually seeded well ahead of them. Paltridge (1955) recorded occasions when it survived the winter and provided new growth in the following summer. Jones (1969) recorded 21 percent survival of plants at Samford after a winter in which the lowest temperature reached -8.3°C.

Tolerance of drought and flooding

It escapes drought by its free-seeding habit. Phasey bean is fairly tolerant of waterlogging and frequently grows in the drains (or water-tables) on the edge of highways in areas where it is adapted.

Vigour of seedling, growth and growth rhythm

It has a vigorous seedling and establishes readily. Grows vigorously in the warm moist summer period.

Response to photoperiod and light

It is day-neutral. Capable of climbing tall grasses, it is not unduly suppressed by absence of light except in the seedling stage.

Minimum germination and quality for commercial sale

Seventy percent germination with a purity of 98 percent and a maximum hard-seed content of 10 percent in Queensland. Seed is germinated at 25°C.