1. INTRODUCTION
This lecture is concerned with legumes that can be planted on pastures or on the veld in order to provide more and much better quality grazing for stock. In temperate climates, particularly in Britain and New Zealand it is common practice to sow grasses and legumes together in pastures. The legumes used are all different types of clovers. Since the clovers are legumes and fix Nitrogen in their root nodules, Nitrogen is added to the soil and is taken up and used by the grasses in the pasture. It has been shown that in these mixed clover-grass pastures, up to 400 kg of Nitrogen per ha can be transferred to the grasses and used by them each season. This is a tremendous asset to the farmer because Nitrogen fertilizers are expensive. The usual practice on such a pasture is to give the grass/clover mixture an initial top-dressing early in the spring to get the grass growing and any further Nitrogen required during the season is supplied from the clover.
A number of pasture legumes have been introduced over the last few years. A great deal of work has been carried out testing these both in pastures and in veld in order to find those which are most suited to our conditions. Due to the long dry winter in Southern Africa, the clovers which are grown in temperate climates cannot be used here except under full irrigation, but legumes have been introduced from Australia and these are proving to be effective.
Most of the information about pasture and veld legumes which appear in this lesson are intended for reference purposes. You are not expected to learn all the detailed information given but should know the names of the legumes and their suitability for growing in pastures and the veld. There is no doubt that they will play an important part in beef production in the future.
2. OXLEY FINE-STEM STYLO
Scientific name Stylosanthes guianensis, also indicated as S.guvanensis. This strain was selected in Australia from plants introduced from S. America. It is a low-growing perennial legume which has a pronounced crown at or just below the surface of the soil. It differs from Schofield stylo (also an S. guianensis strain) in the position of the crown and in having finer stems and smaller leaflets. Theleaves are glabrous and a dark green colour and have sparse long hairs on the internodes.
The flowers are a brighter yellow than those of Schofield stylo and, as fine-stem stylo flowers under long-day conditions it flowers throughout summer. The flowers are borne in clusters which flower from the outside inwards so that seed ripening is uneven within each flower head and some seed is shed before the later seeds mature.
ADAPTATION
Fine-stem stylo is best suited to granite sand soils. Although plants have persisted on red soils they have made poor growth and are not impressive. Fine-stem stylo is tolerant of frost. It can be regarded as complementary to Townsville stylo with the latter recommended for areas below 1 200 m and fine-stem stylo for areas above 1 500 m. Both require an annual average rainfall of at least 700 mm.
Glabrous: free from hair ordown; smooth
ESTABLISHMENT
Fine-stem stylo is best used in veld improvement projects broadcast onto disced strips through burnt veld. It can also be sown in pastures on a well-prepared seedbed but the seedling growth of this
strain is very slow and is not as productive as other more efficient legumes, so these should be sown when the most favourable conditions that were described above, occur.
The recommended seeding rate is 3 – 4 kg/ha. The seeds are small (350 per gram) and should not be covered more deeply than 5 mm.
INOCULATION
Unlike Schofield and Townsville stylos, Fine-stem stylo is highly specific in its rhizobium association and will nodulate only with its own particular strain. In Australia it has been found to require inoculation and, even then nodulation failures are common.
Uninoculated seed has nodulated satisfactorily but the position generally needs clarifying. Until the situation is defined inoculation with the correct strain of Rhizobium is recommended for fine-stem stylo.
USE AND MANAGEMENT
The best way to use improved veld with Fine-stem stylo appears to be for rotational grazing throughout the year especially as the stylo retains some green leaf through the winter and provides a useful green pick. Fine -stem stylo grows well both under heavy summer grazing and when allowed to grow out in summer and then only grazed in winter. It is extremely palatable and stock takes it readily even in summer. This can be a disadvantage as it reduces the amount of stand-over feed for winter use.
In addition to its frost tolerance Fine-stem stylo will also withstand fire and regrows from the crowns after being burnt.
SEED PRODUCTION
As the seed in each flower head ripens so unevenly, some loss of seed is inevitable, even with hand reaping. In Australia, suction harvesters are used to suck up the seed off the ground but hand harvesting seems more feasible. This can be either by pulling off the flower clusters as the seeds in them ripen or by cutting the entire plant when it is estimated that most seeds are ripe. The flower heads are not gummy and the ripe seed is shed from them as the cut plants dry. Australian sources quote 200 kg/ha as a reasonable seed yield but local yields seem higher than this (1000 kg/ha).
SEED TREATMENT
Fine-stem stylo contains a high percentage of hard seed and some form of treatment to break this is desirable. As the seed is sold as enclosed in the single-seeded pod the effects of acid treatment are variable although generally effective.
The current recommendation is to immerse the ‘seed’ in boiling water for 10 seconds and dry thoroughly before sowing. This method is tedious as only small amounts of seed can be treated at one time and more feasible methods are being sought.
Figure 1 and 2: Oxley Fine-Stem Stylo (Stylosanthes guianensis)
Source: keyserver.lucidcentral Source: keyserver.lucidcentral
- TOWNSVILLE STYLO (formerly Townsville Lucerne)
Scientific name: Stylosanthes humills
An annual and biennial legume which is indigenous to tropical South America. This plant was accidentally introduced to the port of Townsville (Queensland) in the early 1900’s where it thrived and spread rapidly from stock routes and trucking yards. In recent years it has attracted much interest and attention from graziers and scientists in Australia.
ADAPTATION
This legume is best suited to the freely drained sandy soils overlying heavier textured subsoils and is recommended for the warm areas found at the lower altitudes (below 1 200 m) and with an average rainfall of at least 700 mm. However, the legume is adapted to a wide range of soils and will grow satisfactorily on many clay and acid soils.
ESTABLISHMENT
Townsville Stylo is best utilised in veld improvement projects by sowing seed onto disced strips through burnt veld. Rolling or a light covering to a depth of approximately 10 mm after sowing is advantageous.
The recommended seeding rate is 2 – 3 kg/ha.
INOCULATION
Effective strains of rhizobia appear to be readily available in soils and inoculation is therefore not necessary.
USE AND MANAGEMENT
Townsville Stylo will spread and grow vigorously only if the associated veld grasses are kept in check. Although cattle will graze the legume throughout the growing period they will seek it out more as the wet season advances. Management to favour Townsville Stylo would therefore be to graze reasonably hard in early summer and then allow the veld to grow in late summer. Overgrazing at the vulnerable seeding stage is to be avoided.
SEED PRODUCTION
The legume flowers from late January onwards. Flowers are borne in clusters at the end of the stalks. Within each cluster the seeds open in sequence, so that a single seed head may contain buds, open flowers, immature and ripe seeds. Due to this, only a small proportion of the total seed produced is carried on the plant at any one time.
With a clover seed harvester available, the top hamper can be removed in the dry season and the mature ripe seed sucked up off the ground. However, as this machine is not likely to be available, the farmer could utilise labour to move through the land pulling off the seed heads as they mature. A useful rule of thumb is to reap each seedhead only after the last flower on the head has withered and dried. A more speedy method but one which reduces the yield, is to cut off the entire plant when it is estimated that the greatest amount of mature seed is available on the plant. The harvested material is spread in a shallow layer to dry and turned at intervals. Townsville Stylo is held tightly in the seedhead and the hooked bristle is a nuisance when sieves are used to clean the seed. The dried plant is therefore best run through a slowed-down hammer mill and the seed separated from the chaff by means of a groundnut winnower.
Yield of single seeded pods: 300 – 400 kg/ha.
Figure 3: Townsville Stylo (Stylosanthes humills)
Source: flickr
SEED TREATMENT
Townsville Stylo seed contains a high percentage of hard seed but as the seed is usually sold in the pod concentrated sulphuric acid treatment is not as effective as it is with several other pasture legumes. Preferably, immerse the seed in boiling water for 10 seconds, dry and sow in the usual way.
4. SIRATRO
Scientific name: Macroptilium atropurpureum
Siratro is a hybrid between two introductions of this species from Mexico (one vigorous but semi-upright, the other less vigorous but rooting at the nodes) bred to combine the better features of both parents. The result is a stoloniferous perennial which roots from the stolons but also has a well-developed tap root. This gives the plant a fair degree of drought resistance. When growing with tall-growing grasses or weeds, Siratro twines up their stems, forming a tangled mass of herbage. The trifoliate leaves are dark green on the upper surface with a mass of fine silver-grey hairs on the
lower and have characteristic lobes on the lower margins of the outer leaflets.
The flowers are dark red, ageing to purple, and are borne above the foliage. There are two main flowering periods September – October and March – April. The pods are straight and cylindrical and shatter when mature. The seeds are dark brown and there are about 76 per gram. A high proportion of the seed is hard and does not swell when moistened.
ADAPTATION
A feature of Siratro is that it grows well on a very wide range of soils, from sands to heavy red. Rainfall should be at least 750 mm (30’’) per annum. Siratro does best under hot growing conditions and is recommended mainly for altitudes below 1 500 m (4 900 ft).
ESTABLISHMENT
Siratro is probably best suited to use in pastures either sown on a well-prepared seed-bed or underseeded into a maize crop. The seed should be lightly covered; a depth of 10 mm being optimum.
Siratro can also be used for veld improvement by sowing seed onto disced strips through burnt veld.
Rolling or light covering of the seed after sowing is advantageous.
Seeding rate is 4 – 6 kg/ha for Siratro sown alone or 3 – 4 kg/ha when sown mixed with a grass.
INOCULATION
Siratro is unrestrained in its rhizobium relationships and nodulates freely with broad-spectrum cowpea inoculant. Effective rhizobia for Siratro are likely to be widespread in soils and there is not likely to be any great benefit from inoculation.
USE AND MANAGEMENT
Siratro is best used for grazing during the growing season. Frost causes almost complete defoliation (but does not kill established plants) and so greatly reduces its value for winter feed. Growth starts in spring as the weather warms up and provides a valuable green ‘bite’ before the start of the rains.
In Australia most of the experimental work has been under continuous grazing and heavy grazing has proved harmful to Siratro. Mixed with Setaria it remained vigorous when grazed by a beast to 0.8 ha (2 acres) but the stand thinned badly when stocked at 1 to 0.4 ha.
Based on trials done where the plant was cut frequently and almost completely defoliated the grazing strategy should be on a rotational basis. Grazing therefore should be to graze neither too frequently nor too severely.
SEED PRODUCTION
The seed pods can be reaped easily by hand as they are held clear of the foliage and the pods shatter as they dry so that threshing is simple and consists mainly of sifting the seed from the split pods. Since the pods shatter so readily, they should be reaped at least once a fortnight to reduce seed losses. The pods ripen unevenly and reaping is likely to be spread over a 6 – 8 week period, so that a single reaping is likely to give only a portion of the total seed produced.
Australian estimates of seed production based on combine reaping are 110 – 170 kg of seed per ha but considerably greater yields can be obtained with hand reaping.
SEED TREATMENT
Zimbabwean-grown Siratro seed commonly contains a very high percentage (over 80%) of hard seed and pre-sowing treatment to reduce hard-seediness is well worth it. At present the recommended treatment is with concentrated sulphuric acid for 20 minutes.
This method is time-consuming and unpleasant as the acid is dangerous and work at Grasslands in Zimbabwe has aimed at finding alternative methods of seed treatment. Hot oven (70°C for 6 hours) and mechanical treatments appear feasible and it is anticipated that these methods could be applied before the seed is sold.
Attack by bean stem maggot can greatly reduce the stand of Siratro seedlings. To prevent this shake the seed with 12.5 ml of 18% or 20% Dieldrin emulsifiable concentrate per kg of seed, or with 3 gram of 50% Dieldrin W.P. in 12 ml water per kg of seed. The seed should be sown within 24 hours of treatment with Dieldrin.
Figure 4 and 5: Siratro (Macroptilium atropurpureum)
Source: commons.wikimedia Source: phytoimages.siu
5. SILVERLEAF
Scientific name: Desmodium uncinatum
This species is indigenous to South America but was first used in pastures in Australia. It is a trailing perennial, a rather coarse hairy plant with long stems which root at the nodes. The trifoliate leaves are distinguished by a broad irregular silver band along the mid rib.
The pale lilac -pink flowers occur in loose clusters at the end of the stalks and appear in March-April. The pods are sickle-shaped about 30 – 75 mm (1 to 3 inches) long and contain 4 to 8 seeds. The pods are covered with hooked hairs and adhere readily to stock or clothing.
ADAPTATION
Silverleaf is not as drought-tolerant as Siratro and is recommended only for area with an annual average rainfall over 800 mm (3 inches). It appears to grow considerably better than Siratro at high altitudes and is recommended especially for altitudes above 1 500 m (4 900ft). It seems to grow well on a wide range of soils.
ESTABLISHMENT
The pale yellowish-green to brown seeds are rather small (about 220 per gram) and should be sown shallowly on a well prepared seedbed. Seedlings of the Desmodium spp. seem very susceptible to dry conditions soon after seedling emergence and for this reason their use on rough seedbeds in disced veld is risky. However, in one trial an excellent stand of Silverleaf has been obtained in disced veld and looks extremely promising.
Seed rate is 3 – 4 kg/ha.
INOCULATION
On sandy soils inoculation with the correct strain of rhizobium appears to be desirable.
USE AND MANAGEMENT
Australian recommendations stress that hard close grazing of Silverleaf can damage the runners and for this reason suggest a system of rapid rotation grazing in which the pasture is never grazed too short. Silverleaf is moderately palatable to stock but is not readily eaten in early summer but acceptance improves in late summer and autumn. The spring growth of Silverleaf is better than that of Intortum, but Silverleaf flowers earlier and Intortum produces more growth in autumn.
Silverleaf is susceptible to ‘Little Leaf’ virus and the pasture should be grazed closely when this occurs.
SEED PRODUCTION
Silverleaf flowers about a month earlier than Intortum and seed set of Silverleaf before it is affected by frost is therefore fairly reliable. Silverleaf grown for seed should be grazed or rolled in late January to reduce the height of the foliage and ensure that the seeds are borne at a fairly uniform height. The seeds can be combined or the seed heads cut by hand and then spread in the sun to dry. The hairy pods tend to clump together and make threshing difficult. It has been found that running the seed through a slow-running hammer mill is a good way of threshing.
Australian estimates of seed yield are 210 – 340 kg/ha.
SEED TREATMENT
The proportion of hard seed in Silverleaf seed is not high and seed treatment is therefore unnecessary.
Figure 6: Silverleaf (Desmodium uncinatum)
Source: www.flickr
6. INTORTUM
Scientific name: Desmodium intortum
This species which is indigenous to South America, a strain of D. intortum is called Greenleaf Desmodium in Australia but it is not certain that the material is identical with this.
Desmodium intortum is a trailing perennial legume which roots at the nodes. The stems are finer and the internodes shorter than those of Silverleaf Desmodium. The leaves of Intortum are dark green often flecked with red and lack the characteristic midrib stripe of Silverleaf. The flower heads are more compact and are a darker colour and appear about a month later than those of Silverleaf.
ADAPTATION
The recommendations for Intortum are similar to those for Silverleaf, i.e. at least 900 mm (35 inches) of rain and an altitude greater than 1 300 m. Observation suggests that Intortum may be better adapted than Silverleaf to very high-altitude sites.
Like Silverleaf, Intortum appears to be adapted to a wide range of soil types.
ESTABLISHMENT
The seeds of Intortum are small (760 per gram) and should be sown shallowly on a firm seedbed. Seedling growth is slow and weeds control in the early stages important. Intortum can also be established by transplanting rooted runners.
Desmodium intortum does not appear to be suitable for use in veld improvement projects.
INOCULATION
Although effective rhizobium strains do occur in soils inoculation of Intortum seed is recommended, especially for sowing on sandy soils.
USE AND MANAGEMENT
Intortum starts growth in spring later than Silverleaf but flowers later in autumn so that its value as late -season feed is greater. When grazing Intortum, the aim should be never to graze so short that the runners are damaged. A stand of Intortum is persists well under a year-round regime of 1-week-graze, 3-week-rest at a stocking rate of 1 weaner per 0.6 ha.
SEED PRODUCTION
The main reason why Kuru Vine was not widely grown was the shortage of seed. In nearly every season, frost hit the plants before much seed had been set. Seed production was, therefore, a matter of chance. A range of introductions of D. intortum has been screened for earliness of flowering and a trial is now in progress to test the extent to which early flowering can be combined with reasonable herbage production.
The seed pods are hairy and stick to clothing like those of Silverleaf. The pods tend to clump so can be threshed in a slow-running hammer mill.
SEED TREATMENT
The hard seed content of Intortum is generally relatively low and seed treatment is not necessary.
Figure 8 and 9: Intortum (Desmodium intortum)
Source: commons.wikimedia Source: commons.wikimedia
7. BEIT LOTONONIS
Scientific name: Lotononis bainesii
Lotononis Bainesii is indigenous to South Africa and is especially widespread in Gauteng, Mpumalanga and Limpopo. The Beit strain of this species was selected at Grasslands in Zimababwe in a series of co-operative trials with the Tobacco Research Board for resistance to the root-knot nematode.
Lotononis is a prostrate perennial legume with long stolons which root freely at the nodes. As it has a pronounced tap root it gives the plant a degree of drought tolerance. The leaves are trifoliate with narrow shiny leaflets and range in size from 5 to 50 mm long. The yellow flowers are borne above the foliage in ball-like clusters on stalks 70 – 80 mm tall. There are 2 flowering peaks, September – October and March – April. The seeds are very small (about 3 000 per gram) and contain a high percentage of hard seed.
ADAPTATION
Lotononis bainesii occurs on a wide range of soils and under a fair variation of rainfall in theGauteng, Mpumalanga and Limpopo areas. It seems to be best adapted to the high-altitude high-rainfall area. Current recommendations would therefore be for regions above 1 200 m (4 500 ft) receiving at least 750 mm (30 inches) of rain annually. Lotononis tolerates acidity and seems to do best on sandy soils although it is growing well on tatagura soils at Henderson.
ESTABLISHMENT
The seed is so fine, therefore Lotononis should be sown at a seeding rate of ½ – 1 kg/ha on a firm well-prepared seedbed and lightly rolled. Lotononis can also be established by transplanting rooted runners.
One can successfully use Lotononis for veld improvement broadcasting the seed on disced strips and then rolling.
INOCULATION
Lotononis bainesii is highly specific in its Rhizobium association and effective strains of bacteria arenot usually present in South African soils. Inoculation with the correct stain of Rhizobium is therefore essential for successful growth.
USE AND MANAGEMENT
Lotononis is a low-growing legume and the standard advice in all the Australian journals is that
swards containing Lotononis should be kept closely grazed in summer to prevent the legume being shaded out. In our veld improvement trails, Lotononis has done particularly well when rested all summer and grazed only in winter. It is the most frost-tolerant of the tropical legumes and has some green foliage throughout winter. It starts regrowth well before the beginning of the rains.
Although Lotononis is eaten readily by cattle in autumn and winter, it is not normally grazed in early summer and stock tends to concentrate on the associated grasses. Management to favour the Lotononis would therefore be to graze hard in early summer and then allow the pasture to grow out in late summer.
Lotononis is susceptible to the ‘Little Leaf’ virus (which produces an effect similar to ‘Bushy Top’ in tobacco. Stands affected by this virus should be grazed hard and the regrowth will usually be found to have recovered.
SEED PRODUCTION
The seed heads of Lotononis ripen unevenly and the pods shatter as they dry so seed yields of Lotononis obtained by combining are usually low – Australian sources quote 56 kg/ha as normal. Greater yields of seed can be obtained by hand-reaping (pulling off the seed heads as the seeds ripen) but, this is laborious and cleaning such fine seed requires considerable care. This explains the rather high price of the seed per kg but, to offset this, only low-seeding rates are necessary. i.e. ½ – 1 kg/ha.
SEED TREATMENT
Due to the climatic conditions at the time it is reaped and because it is reaped, cleaned by hand and not subjected to the abrasion which occurs in combine harvesting, Lotononis seed has a very high percentage of hard seed.
Treatment with sulphuric acid gives variable results and is not recommended. Hot water treatment may be suitable (one source suggests immersion in hot water at 70°C for 5 minutes) but mechanical scarification seems to offer the best chance of overcoming the problem. Current tests at Grasslands involve the use of a drum with rotating sandpaper-covered discs to abrade the seed. It is anticipated that the recommended treatment would be applied before the seed is sold.
Figure 10 and 11: Beit Lotononis (Lotononis Bainesii
Source: noosanativeplants Source: noosanativeplants
8. KENYA WHITE CLOVER
Scientific name: Trifolium semipilosum
Kenya White Clover is indigenous to the highlands of that country occurring at altitudes of between 1 500 and 3 000 m. In appearance it is very similar to the European white clover (Trifolium repens) but has a more developed tap root and is more drought resistant. It is better adapted to acid and infertile soils than T. repens and has a degree of resistance to root-knot nematode.
ADAPTATION
Kenya White clover is best suited to the moister conditions but has persisted in dryland pastures, especially in damper areas. It shows promise for use in vlei pastures.
It is suitable for use in irrigated pastures anywhere.
ESTABLISHMENT
Kenya White Clover should be sown at a scale of 2 kg/ha on a firm seedbed and rolled in. The seeds are small (1 300 per gram) and should not be covered deeply. For irrigated pastures clover is probably best sown in autumn.
Inoculation
Effective strains of rhizobia for Kenya White Clover are not found in South African soils; therefore, inoculation with the specific strain is essential for success with this legume. This strain is NOT the same as for Trifolium repens. Lime pelleting seed of Kenya White clover has also proved beneficial.
USE AND MANAGEMENT
It has proved difficult to get a good grass-clover mixture at Grasslands and our pastures are now clover dominant with the associated risk of bloat. Kikuyu seems the best grass to grow with Kenya
White clover both under irrigation and on dryland. The temperate adage of ‘graze hard to favour the legume, lightly to favour the grass’ is likely to apply to pastures containing Kenya White clove, but not to those with tropical pasture legumes.
SEED PRODUCTION
Pastures from which clover seed is reaped should be grazed flat in mid-February, which will give a short even height of pasture with seed heads carried above the foliage. This simplifies combining or the pasture can be mown when the seed is ripe, windrowed and then stacked for final drying. For small areas the ripe seed heads can be picked by hand and later threshed with a slow-running hammer mill.
Seed yields are likely to be of the order of 200 – 300 kg/ha.
SEED TREATMENT
Kenya White clover contains a very high proportion of hard seed, especially when hand-reaped and cleaned and some form of seed treatment is advisable. At present acid treatment for 20 minutes is recommended, but work is in progress to devise alternative more feasible methods.
Figure 12 and 13: Kenya White Clover (Trifolium semipilosum)
Source: esacademic Source: tropicalforages
9. ARCHER
Scientific name: Macrotyloma axillare
This species is widespread in Africa and occurs naturally in South Africa. The Archer cultivar, however, was selected in Australia from plants which originated in Kenya.
Archer is a twining perennial with shiny light -green trifoliate leaves. Grown alone it forms a tangled mass of herbage and mixes well with tall grasses by twining up their stems. The insignificant yellowish green flowers are borne on short stalks in the leaf axils and are over topped by the foliage. This poses problems in seed collection as the seed pods shatter as they ripen.
ADAPTATION
In Australia, Archer is regarded as very similar to Siratro in its climatic requirements and, until greater experience produces modifications it is recommended for areas below 1 500 m (4 900 ft) receiving at least 750 mm (30 inches) of rain per annum. It must be grown on well-drained soils as it does not tolerate waterlogging.
ESTABLISHMENT
Archer is recommended for use in pastures, sown onto a well prepared seedbed at a rate of 4 – 6 kg seed per ha. There are approximately 120 seeds per gram and seed should not be sown deeper than 10 mm.
INOCULATION
Archer nodulates freely with broad-spectrum cowpea inoculant and, as Macrotyloma axillare is widespread, seed of Archer should not need to be inoculated under local conditions.
USE AND MANAGEMENT
Stock takes some while to become accustomed to Archer herbage and initial acceptance is usually low. For this reason grazing during the early part of the growing season will usually favour the Archer when grown in mixed swards with grasses. The main value of Archer is likely to be in autumn or early winter, and again in Spring as growth starts well in advance of the rains. Without further experience, the only advice which is possible on grazing management is as with all twining legumes to avoid grazing too severely or too frequently during the growing season.
The only disease problem encountered to date with Archer has been attack by red spider mite.
SEED PRODUCTION
Australian figures for seed yields range from 200 to 560 kg/ha. The seed is not easy to reap by hand as the pods are hidden in the tangled mass of foliage. In practice, it will probably prove best to reap seed from first-year stands of the legume as these are not so thick and flower later than older stands. The individual pods can be hand-picked or the whole plants cut off and placed on a threshing floor to dry. Due to the seed pods shattering so readily, threshing is simple and consists mainly of sieving the seed from the herbage.
SEED TREATMENT
Local seed of Archer contains a high percentage of hard seed and seed treatment is indicated. Hot oven treatment appears promising but optimum temperature and time of treatment still need to be defined.
Figure 14 and 15: Archer (Macrotyloma axillare)
Source: keyserver.lucidcentral Source: mozambiqueflora
10. COOPER GLYCINE
Scientific name: Glycine wightii
Glycine wightii is an indigenous legume widespread in South Africa occurring most commonly on theheavier soils. On the sands it is usually found on or near ant heaps. There are 3 cultivars of this species which are grown in pastures in Australia, of which Clarence is the earliest, and Tinaroo the
latest flowering. The cultivar Cooper seems more promising for pasture use than the other cultivars or any of the indigenous strains that have been tested. Cooper originated in Tanzania, is later-flowering than most of the indigenous strains, and has the reputation of being the most drought-tolerant of the Australian cultivars.
Glycine wightii is a twining perennial legume which roots from the vigorous stolons. Cooper can bedistinguished from most glycine strains by its almost greyish colour due to the mass of fine hairs covering the leaves and stems. The small white flowers are borne in clusters at the ends of the stems and appear in late March or April. The pods are about 30 mm long, brown when mature and are constricted between the seeds.
ADAPTATION
As would be expected from its natural distribution, Glycine is basically a pasture legume for the heavier more fertile soils. The average annual rainfall should not be less than 750 mm (30”). Glycine seems better adapted than Siratro to higher and cooler situations but is not suitable for poorly-drained soils.
ESTABLISHMENT
There are approximately 140 seeds per gram and Glycine seed should be sown on a firm, well-prepared seedbed at a rate of 3 – 5 kg/ha. Seedling growth is initially slow as nodulation is often delayed and reduction of competition from weeds in the seedling stage is important.
INOCULATION
As Glycine wightii is widespread in South Africa especially on the heavier soils effective strains of rhizobium should also be widespread and inoculation should be of doubtful value.
USE AND MANAGEMENT
It is difficult to comment on the optimum management practices for Glycine. When used for veld improvement it looks especially impressive when it is rested all Summer and grazed only in Winter.
Australian literature emphasises that young stands of Glycine should be grazed leniently to allow the legume to develop, but that established stands of Glycine can stand heavy grazing. It is not particularly palatable to stock although they take it readily in late Summer and Autumn.
SEED PRODUCTION
Australian figures for seed yields reaped by combine range from 200 to 350 kg/ha. Hand reaping by cutting the stalks as the pods ripens, so threshing is easy.
SEED TREATMENT
Glycine contains a high percentage of hard seed and, especially with hand-reaped seed treatment, may be advantageous. At present acid treatment for 20 minutes is recommended but work is in progress to devise simpler methods.
Figure 16 and 17: Cooper Glycine (Glycine wightii)