Pueraria phaseoloides (Roxb.) Benth.

Synonyms

P. javanica Benth.; P. phaseoloides var. javanica (Benth. ) Hook.

Puero (Australia), tropical kudzu (most of the tropics).

Vigorous twining and climbing, slightly woody, hairy perennial legume, deep-rooting and rather slender. Its main stems are about 0.6 cm in diameter and may extend for 5 to 6 metres. They may root at the nodes and from the nodes a number of lateral or secondary branches are formed. These intertwine and may result in a tangled mass of vegetation 60 to 75 cm deep within eight to nine months of sowing. The young shoots are densely covered with brown hairs. The leaves are large and trifoliate, borne on petioles 5 to 10 cm long covered with ascending hairs. 

It is native to south-east Asia Malaysia and Indonesia and is now widespread throughout the wet tropics.

Essentially a plant of low altitudes, it generally grows below 600 m, but in Tanzania it reaches 1 000 m and in Colombia 2 000 m (Crowder, 1960). Altitudes above 1 200 m are too high in Kenya.

Grows best in a rainfall exceeding 2 500 mm or in swampy land in areas of lower rainfall. In Tanzania, it grows in a minimum rainfall of 850 mm as a cover crop in sisal but grows better at 1 160 mm at Mlingano, Tanzania (Hopkinson, 1969). At 2 000 mm it is difficult to control in cocoa.

Has a wide range in soil adaptability, from sands to clays, although it does not grow well in tight heavy clays. Does well on sands and clays in Suriname, on latosols in Tanzania and north Queensland, Australia. Loustalot and Telford (1948) found a pH of 4 to 5 to be best. Fe deficiency showed at a pH of 6 to 8. N production was greatest at a pH of 4. Landrau et al. (1953) quote good growth at pH 4.5 on a lateritic soil, and at pH 4.6 to 5.1 in a clay. Best growth at pH 5.5 was recorded by Smith and Chandler (1951) but other co-workers increased growth by liming from pH 5.3 to 6.5 and, in the greenhouse, from pH 5.2 to 7.5. Molybdenum release may have been responsible. It is not tolerant of salinity.

A promiscuous species; nodulates with the cowpea type of Rhizobium, strain CB756 in Australia. However, Bowen (personal communication) obtained nearly double the yield from inoculated plants (as compared with the uninoculated control).

Spreads mainly by runners and in this way colonizes widely on suitable soils with adequate rainfall.

As early growth is slow, seed should be sown into a weed-free seed bed. It responds to good seed-bed preparation, which controls weeds by cultivation after the initial ploughing. Can also be established readily in the ashes of a forest burn.

Seed is usually broadcast or drilled in. In Sri Lanka it is hand planted (15 to 20 seeds every 3 m mixed with the top 2.5 cm of soil). Drill in rows 1 m apart. Can also be propagated by cuttings 0.7 to 1 m long planted at two per point on a 1- to 2-m grid (Schofield, 1941). Establishment can be achieved by oversowing into existing pasture if the pasture is disced or burnt beforehand. Usually, however, it will not establish in grass, but grass will establish in the legume (Santhirasegaram, personal communication). It is best sown in midsummer to coincide with the wet season. Sow at 1 to 2 kg./ha in mixture. Rijkebusch (1967) recommends 3 to 6 kg./ha scarified or 8 to 10 kg./ ha unscarified seed for sowing down the centre of sisal rows which are 3.5 m wide. Sow at 1.5 cm and roll or harrow.

81 400 to 88 000.

Eighty percent (Colombia) to 95 percent (Venezuela).

To break dormancy: (a) treat with concentrated sulphuric acid (sp. gr. 1.8) for 20 minutes, wash and dry (Rijkebusch, 1967; Prodonoff, 1968); (b) put in hot water at 50 to 70°C for several hours and allow to cool (Wycherley, 1960); (c) immerse in glycerine at 50°C for one hour­this increased germination from 10 to 50 percent (Wycherley, 1960); or (d) use infra-red lamp irradiation­Philips Infraphil Type 13373F/479 (150 watts) for one hour or Osram I.R.R. 4892 (250 watts) for two hours (Wycherley, 1960). Inoculation is advisable but not necessary. Pelleting is usually not necessary. Insect and disease control are usually not required.¸€

Dirven and Ehrencron (1969) have intensively tested the nutrient requirements of Pueraria phaseoloides and have published coloured photophaphs of the deficiency symptoms. They found that the lowest yields were with rain-water alone and minus phosphorus. Minus Ca and Mg reduced yields by 72 and 84 percent respectively and the plants did not recover when fertilized with a complete mixture four months later. Minus K, Na or N reduced yields by 50 percent. Nodulation was lacking without calcium, fair with complete fertilizer and minus K, P, Mg or Na; good with rainwater, and very good with minus N. After complete fertilization, nodulation was very good in the minus Na, good in the minus N, Mg and in the rain-water treatments, and fair in all the others. In the absence of Ca, P or Mg, root systems developed slowly.

• Boron: 

Landrau et al. (1953) found that boron applied as 33 kg./ha of borax had no effect on yields or nodulation in an acid lateritic clay of pH 4.4.

• Calcium: 

Watson (1960) found that the Ca content of the leaf, stem and nodules was increased by liming to pH 6.0, with a smaller increase with liming to pH 7.0. The side-effect of liming, however, was to release molybdenum, especially at pH 7.0, the Ca and Mo contents rising appreciably. Liming also decreased the Mn content markedly. Pueraria phaseoloides is the most successful leguminous cover crop in sisal (Agave sisalana), which is a luxury consumer of calcium and is usually heavily limed. Loustalot and Telford (1948) found that lack of Ca caused rotting of the root system. The chlorophyll of the leaves faded along the margins and between the main veins, and the green was replaced by a buff pigment around the midrib. The area immediately adjacent to the main vein was unusually dark green. The leaves dropped before they became necrotic. The plants gave 57 percent of their maximum yield in the absence of Ca. Calcium deficiency appeared early and very few nodules were produced, some of which were decayed. Dirven and Ehrencron (1969) found that the omission of calcium resulted in less well-developed plants. Only a few new leaves and vines were formed. The root system was found to be small and there were no nodules. About three months after germination, dark yellow patches slowly spread to the leaf margin and base. The veins and the leaf top remained green for a considerable time, but eventually the entire leaf yellowed. Necrosis developed in the interveinal spaces, even after the first yellowing. As soon as the leaves had entirely yellowed, the tissue of the leaf tip or leaf margin began to die off. A brown coloration of the veins was observed on the top and underside of some of the leaves. Young leaves also exhibited distinct deficiency symptoms.

• Magnesium: 

Dirven and Ehrencron (1969) found that magnesium deficiency produced very weak plants with fairly small leaves and a poorly developed root system.
Necrosis occurred dispersedly over laminae and also at the tips and margins of the leaves. When the plants were supplied with a complete nutrient solution there was a slow and incomplete recovery.

• Nitrogen: 

Loustalot and Telford (1968) found that absence of N produced no symptoms but yields were only 55 percent of their maximum. Nodules were very large and moderately numerous. Landrau et al. (1953) found that puero responded to nitrogen at 275 kg./ha for the first cutting at four months from planting when nodule numbers were small; thereafter, no response was obtained. A similar response to early and also late nitrogen applications was recorded by Hopkinson (1969). Parbery (1967a) obtained a response to 100 kg. N/ha in the Kimberley area of northern Australia. Evidently the puero nodules do not become active fixers of nitrogen until about four months after germination.

• Phosphorus: 

Loustalot and Telford (1948) obtained increased yields with puero from applications of phosphorus. In the absence of P, no symptoms were visible for two months after planting and then the basal leaves turned yellow and abscissed. The root system was abnormally large, with a low top-to-root ratio, and there were very few nodules, which were also small. In the absence of P, puero plants produced 87 percent of the yield of dry matter with complete fertilizer in pot tests. P had a highly beneficial effect (at 100 kg./ha P205) on poorly drained soils and there was a positive P x K interaction. The plants growing without P on these soils were chlorotic and small. Grof (1966) obtained linear responses to phosphorus with puero up to at least 110 kg./ha of P2O5, the response by puero in dry-matter yields being significantly higher than by centro and stylo. Dirven and Ehrencron (1969) found that P deficiency resulted in stunted growth. Only a few new leaves and vines were formed and the leaves were small and stiff, olive-green in colour, and in some cases the leaf margin was wavy in the middle. After application of complete nutrient solution, puero made a rapid recovery.

• Potassium: 

Loustalot and Telford ( 1948) found that K deficiency produced partial chlorosis and/or necrosis between the veins. The basal leaves were affected first, later the apex. Yellow areas at the margins of the leaves and between the veins extended irregularly inward. Entire leaf margins became chlorotic and then necrotic. In the absence of K, the yields were 87 percent of the maximum yield from complete fertilizer, and nodules were abnormally large and moderately numerous. Landrau et al. (1953) found that puero competed unsuccessfully with Merker grass (Pennisetum purpureum) for small K supplies in the soil. Chlorotic symptoms appeared on the margins of the legume leaves. Normal leaves were found to contain 2.20 percent of K in the dry matter, while chlorotic leaves contained 1.28 percent, and the N and P percentages were also low. Other workers have found that potash is deficient when the dry matter of the tops is less than 1.60 percent.

• Sodium: 

Dirven and Ehrencron (1969) found no sodium deficiency symptoms in puero supplied with a minus Na nutrient solution, but the top leaves were noticeably large. They stated that the significance of sodium deficiency was obscure, since few puero leaves contain less than 0.2 percent Na in the dry matter.

Grows well with cori grass, molasses grass, guinea and elephant (napier) grass, but cannot persist with Brachiaria decumbens or pangola grass. As a cover crop it is often sown with centro and calopo. Calopo dominates the cover in the first year, then puero becomes dominant and finally Centrosema persists (Wilson and Lansbury, 1958).

From greenhouse work, 2,4-DB, ametryne, linuron and 2,2-DPA were promising preplant herbicides that could be safely used before sowing Pueraria phaseoloides (University of the West Indies, 1963). Riepma (1965) found that puero was adversely affected by both pre- and post-emergent application of neburon. The pre-emergence treatment was 2.2 to 4.5 kg. active ingredient per hectare applied one day after sowing; the post-emergence application was made six to eight weeks after sowing. The growth of puero was impaired on sandy soil but not on clay soil at the 4.5 kg./ha rate. Increasing the seeding rate helped overcome the adverse effect. Hopkinson and Breitenstein (1969) found that 2 kg. acid equivalent/ha of MCPA killed the runners of puero.

Schofield (1945) found puero to be a better contributor of nitrogen to the soil than calopo, centro and stylo. After 18 months' growth, it was ploughed into the soil. The nitrogen content of a similar soil under bare fallow was 34.4 ppm, and in the soil into which puero was ploughed it was 171.8 ppm compared with 71.7 for centro, 66.7 for calopo and 54.5 for stylo. Hopkinson (1969) found that puero used as a green cover in sisal increased the fibre yield by 26 percent and equalled the yield with puero plus nitrogen. Rijkebusch (1967) found that puero had the same effect with sisal as the application of 635 kg. N/ha in Tanzania. Oke (1967b) showed that puero fixed 9.3 mg N/plant/day, compared with 3.8 mg for Calopogonium, and transferred 92 percent of the fixed nitrogen to the plant tops, compared with 87 percent for calopo. Bruce (1967) found that an elephant (napier) grass/ puero pasture added 143 kg. N/ha/year to the top 15 cm of soil and raised the protein content of the grass by 7.1 percent. In puero stands, puero is self-mulching and adds considerable nitrogen by mineralization of leaf fall (Horrell, 1958).

It is moderately tolerant of defoliation, and recovers well after lenient grazing. Vicente-Chandler, Caro-Costas and Figarella (1953) found that cutting at 25 cm instead of 10 cm favoured puero in a molasses grass/puero mixture and gave better rooting and drought resistance.

Should be leniently grazed at all times to maintain the botanical composition of the pasture, as it is very palatable when selectively grazed. If it dominates the pasture mixture, grazing pressure can be increased.

Little tolerance.

Self-fertile; chromosome number 2n = 22.

Grof (personal communication) obtained 9 607 kg. DM/ha in north Queensland from three cuttings made up of 3 684 kg./ha at the end of the wet season in June, 2 483 kg./ha at the second cut in the cool dry season in September, and 3 440 kg./ha from a third cutting in the wet season in January. Payne et al. (1955) obtained an average of 4 180 kg. DM/ha/ year over three years at Sigatoka, Fiji, 62 percent being obtained in the wet season, 38 percent in the dry. In Suriname (lat. 4 to 6°N),30 to 35 tonnes of green fodder per hectare per year have been harvested. Vicente-Chandler, Caro-Costas and Figarella (1953) obtained dry-matter yields up to 22 896 kg./ha with a molasses grass/puero pasture with a protein content of 10.39 percent. The contribution of puero was 9 141 kg. DM/ha, with a protein content of 16.35 percent.

It has been made into hay successfully in Colombia. It can stand two to four cuttings per year to give a hay yield of 4 tonnes/ha/ year (Crowder, 1960). Cabrera and Rivera-Brenes (1953) prepared silage from a mixture of tropical kudzu and Pennisetum purpurascens (Merker grass) in Puerto Rico, and fed it to dairy cows with no beneficial effect compared with feeding green Merker grass, but the protein contents of two grass/ legume silage samples were only 6.35 and 4.71 percent, while the green Merker grass had a protein content of 6.08 percent. No proportions of legume to grass were cited. It also makes good silage mixed with sorghum (one-third legume, two-thirds sorghum) and with elephant grass.

In frost- and fire-free areas, it is excellent as standover feed for the dry season.

It is a valuable fodder plant and has given excellent results in the wet tropics.

• Chemical analysis and digestibility: 

Reyes (1955) found that puero contained 8.4 percent fibre and 3.65 percent protein in green material with 22.59 percent dry matter. In the Kimberley district, Parbery (1967a) reported 11.6 percent protein, and Bermudez et al. (1968) reported 19.9 percent protein in Colombia.

• Palatability.: 

Puero is very palatable. At South Johnstone, north Queensland, the palatability rating is puero > Vigna hosei > stylo > centro > Desmodium heterophyllum > calopo (Barrau, 1953).

None reported.

Seed is often harvested by hand in the tropics. It can be machine-harvested directly in the field, but low yields result because of the uneven maturity of the pods.

Yields are often affected by the legume pod borer. With full insect control, 330 kg./ha can be obtained by hand harvesting, 55 kg./ha by machine.

At present there is only the one commercial line available in Australia. Cultivar IAC in Brazil has been reported by Souto (1969) to be more heat-tolerant than other types.

Its compatibility with guinea and elephant (napier) grasses and its longer season of growth and higher yield than centro; high palatability; one of the best of the tropical legumes in nitrogen production; smothers weeds effectively.

Slow establishment; sensitivity to overgrazing; fire and drought intolerance; difficulties in seed production.

Puero has been an excellent cover crop to prevent soil erosion and to contribute nitrogen in plantation crops in the tropics for many years. Pereira et al. (1954) found that it gave very good protection of the soil for three years, but that its effect on structure was only transient. Hopkinson (1969) and Rijkebusch (1967) found its nitrogen-fixing ability of great value in sisal. Teitzel (1969b) reported that puero-based mixed pastures were some of the most productive under grazing in the wet tropics of north Queensland.
Vicente-Chandler, Caro-Costas and Figarella (1953) obtained 550 kg./ha live-weight gain with a molasses grass/puero mixture.

Dirven and Ehrencron (1969); Loustalot and Telford (1948); Schofield (1944).

It extends to about 23°S, but for best performance should be grown in equatorial regions down to 17.5°S.D

It is one of the best tropical legumes for smothering weeds; hence, its wide use as a cover crop in sisal (Hopkinson, 1969) in Tanzania, and in smothering nut grass (Cyperus rotundus) in Venezuela.

Manganese­none described, though Watson (1960) found that the addition of lime markedly reduced the manganese content of the plant.

It is remarkably free from disease. Leaf-eating caterpillars cause damage in ungrazed plots; pod borers interfere with seed production.

Optimum about 15°C. Minimum about 12.5°C. Ludlow and Wilson (1970) obtained only 8.3 percent of the dry matter, 24 percent of the relative growth rate and 4 percent of the leaf area at 20°C as was produced at 30°C, indicating that puero is essentially a species for the humid tropics. It developed chlorotic leaves at the lower temperature. It is easily killed by frost.€

Not drought tolerant. In prolonged dry periods it sheds its leaves but survives at Mlingano, Tanzania (Hopkinson, 1969). Kannegieter (1966) found it to be drought resistant in the forest zone of Ghana. It is one of the best tropical legumes for tolerance to waterlogging and nodulates freely in very wet soils; it can stand short periods of flooding.

In the seedling stage, has only moderate vigour and should have little competition. Grows slowly for three to four months in Colombia and then grows well, probably coinciding with active nodulation. Once established it is very vigorous, quickly smothers weeds and will climb trees and fences.

A short-day plant; it flowers about 180 days from seeding in north Queensland, and in 126 days in the Kimberley district of north Australia (Parbery, 1967a). It tolerates partial shading, such as the edges of rain forests and in plantation crops such as coconuts. In Sri Lanka, it is the best legume under coconuts, growing with Brachiaria miliiformis (cori grass), but the trees should be at least 25 years old to provide enough light at ground level, with 150 to 180 trees/ha.

Fifty percent germination, with a maximum of 10 percent hard seed and a purity of 93.5 percent in Queensland. Seed is germinated at 25°C under cover (Prodonoff, 1968).