Chamaecytisus prolifer var. palmensis


Scientific name

Chamaecytisus prolifer (L. f.) Link subsp. prolifer var. palmensis (H. Christ) A. Hansen & Sunding

Other conspecific taxa:
Chamaecytisus prolifer (L. f.) Link
Chamaecytisus prolifer (L. f.) Link var. calderae Acebes
Chamaecytisus prolifer (L. f.) Link var. perezii (Hutch.) G. Kunkel
Chamaecytisus prolifer (L. f.) Link var. prolifer
Chamaecytisus prolifer (L. f.) Link subsp. angustifolius (Kuntze) G. Kunkel
Chamaecytisus prolifer (L. f.) Link subsp. prolifer var. canariae (H. Christ) G. Kunkel

Synonyms

Chamaecytisus palmensis (H. Christ) F. A. Bisby & K. W. Nicholls
Chamaecytisus prolifer (L. f.) Link subsp. palmensis (H. Christ) G. Kunkel
Cytisus palmensis (H. Christ) Hutch.
Cytisus prolifer L. f. subsp. palmensis H. Christ
Cytisus prolifer L. f. var. palmensis H. Christ

Family/tribe

Family: Fabaceae (alt. Leguminosae) subfamily: Faboideae tribe: Genisteae. Also placed in: Papilionaceae.

Common names

tagasaste, tree lucerne, escobon (Spanish).

Morphological description

Perennial, evergreen, hardy, unarmed tree, 5-6 m in height with a crown diameter of a similar size.  It has long drooping softly-hairy, leafy branches.  Leaves dull, bluish-green trifoliate.  Leaflets narrowly rhombic with entire margins up to 7 cm long.  Petiole up to 2 cm long.  Stipules minute.  Inflorescences creamy white, scented, axillary borne in clusters.  Seed pods black, pubescent , flattened, up to 5 cm long with about ten flattened oval-shaped brown-black seeds 3 x 5mm. About 45,000 seeds/kg.

Distribution

Native to:
Europe:  Spain (Canary Islands).

Other:
It is extensively planted as a fodder shrub or for land rehabilitation and is naturalized in New Zealand and Australia, where it was introduced in 1879.

Uses/applications

Used as a multi-purpose fodder tree for cut and carry as a productive source of high quality, palatable and non-toxic fodder and seed for livestock and poultry in the tropical highlands and subtropics.  Also used as an ornamental and windbreak and for bee forage, fuelwood and biogas.  Tagasaste can be planted as a hedge and also has potential for alley cropping systems.

Ecology

Soil requirements

Tagasaste prefers light well-drained sandy soils on slopes and hillsides, but thrives on gravels, loams, limestones and laterites.  Slag heaps and mining dumps can also reportedly be planted with the tree.  It has wide adaptability to a range of soil pH and although growing better on acid soils as low as pH 4.0, it can also survive on sandy, alkaline soils with pH 8.5.  It is not tolerant of saline soils.

Moisture

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It is extremely drought tolerant and thrives under annual rainfalls between 350-1,600 mm.  Drought tolerance is due to its deep rooting habit of 10 m or more and it can survive in areas with as low as 200 mm rainfall, although it requires rainfall above 600 mm for good production.  It is very sensitive to poor drainage and cannot tolerate water logging.

Temperature

The normal range for cultivation is from 1,000-2,000 m altitude.  Tagasaste grows well up to altitudes approaching 3,000 m in the tropics and is one of the few fodder trees that can withstand frost as low as -9ºC in the tropical highlands, although care should be taken with small seedlings, which are more sensitive to frost.

Light

No information available.

Reproductive development

Profuse flowering of the scented, creamy-white flowers occurs during the rains and early dry season in the tropical highlands or cool wet winter months in a Mediterranean climate.

Defoliation

The tree readily coppices and, during the 2- to 3-year establishment period, can be pruned back to the ground to encourage multiple stems.  It responds well to frequent cutting, although regrowth is slow for the first weeks after harvest, increasing with time.  Harvesting in the dry season leads to stunted regrowth, low biomass yields and increased plant mortality.  Trees should be protected from browsing by livestock for at least 2-3 years.  When young, sheep will eat the bark and kill the tree if it is not protected, but once well-established sheep can browse them all year round and have a remarkable capacity to recover from defoliation .  It is reported that trees persist for up to 30 years if well managed.

Fire

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Tagasaste does not burn readily because it stays green during the dry season.

Agronomy

Establishment

Tagasaste is hard seeded and seeds require scarification in hot water prior to planting.  Seedbeds should be well prepared to a fine, firm tilth with no weeds.  Weed control is essential for successful establishment.  Seeds can be directly sown at sowing depths of 1-2.5 cm, although deeper sowing may be necessary in sandy soils in dry areas to ensure sufficient water for germination.  Establishment can also be through transplanting nursery-raised seedlings but care should be taken not to over-water the young seedlings to avoid damping off.  Seedlings of about 45 cm height can be transplanted into moist soft soil in rows 5 m apart and 2.5 m between plants in the row, giving a density of about 700 trees per hectare.  Very high densities of up to 10,000-20,000 seedlings per hectare have also been used successfully.

Fertiliser

Tagasaste is a nitrogen fixing tree but 200 kg/ha/year of superphosphate is needed to maintain high yields.  It uses the same rhizobium inoculant as cowpea.

Compatibility (with other species)

It can be used in alley farming and is an excellent windbreak.

Companion species

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Pests and diseases

It is very sensitive to root rot caused by Phytophthora and also damping off caused by Fusarium .  These are the major limitations to its use in humid areas or on vertisols.  It has few insect pest problems but is susceptible to the tree lucerne moth  (Uresiphita ornithopteralis) and slugs, cutworms and grasshoppers eat emerging seedlings.

Ability to spread

Spreads by seeds from the dehiscent pods.  However, hard seeds may not germinate in the soil for several years, and susceptibility of young seedlings to grazing limits its survival to protected or fenced areas.

Weed potential

A fast growing species used for fodder and is invasive in a wide rage of landscapes.  It has naturalised in almost all areas where it has been planted, along roadsides or in adjacent bushland.  On lateritic soils in higher rainfall areas it is a serious invader of disturbed bushland.

Feeding value

Nutritive value

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The nutritive value of leaves is similar to that of lucerne (Medicago sativa ).  Leaves contain from 20-30% protein when young with high in vitro dry-matter digestibility (0.77-0.82) and no reported toxicity.  The leaves have a low sodium content and marginal levels of phosphorus and sulphur.  Leaves are high in vitamin A and when used for poultry feed, can increase the colour in egg yolks.

Palatability/acceptability

The leaves are reported as highly palatable.  However, livestock take a little time to get used to it as a feed, and crossbred dairy cows in Ethiopia would not consume large quantities of wilted forage , resulting in reduced dry matter intake.

Toxicity

Tagasaste has been fed to sheep for long periods without any problem and there are no reports of toxicity in sheep, cattle, goats, deer or poultry.  Levels of tannins are low.  No cases of bloat have been reported after feeding with tagasaste.

Production potential

Dry matter

Research results from Western Australia and New Zealand suggest edible dry matter yields of 11 t/ha/yr are obtainable in good growing conditions but edible biomass yields of about 5 t/ha were obtained after 6 months regrowth in the Ethiopian highlands.

Animal production

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Growing lambs showed liveweight gains of 95±30 g/day on a cut and carry system with tagasaste in New Zealand and up to 35 g/day when supplemented with 60% of the diet in Ethiopia.  Mineral licks are recommended when feeding tagasaste due to the low levels of minerals in the leaves.

Genetics/breeding

Both self and cross-pollination occurs, as the flowers are self fertile and often cross-pollinated by bees.

Seed production

Tagasaste is a prolific seeder.  The pods ripen in the dry season and are dehiscent .  Pods are usually harvested before shattering and dried in thin layers in the sun to release the seeds.

Herbicide effects

Tagasaste is tolerant to a range of herbicides applied pre-emergence, including those containing simazine, diuron, terbutryne, alacglor, fluazifop butyl, linuron, propyzamide and methabenzthiazuron.

Strengths

  • Extremely drought tolerant.
  • Fast growing, palatable fodder.
  • Frost tolerant.

Limitations

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  • Will not tolerate poor drainage or waterlogging .
  • Young plants are easily eaten out and must be protected from grazing.

Other comments

Despite its wide use as a fodder tree in the cool tropics there are no commercial cultivars available.

Selected references

Borens, F.M. and Poppi, D.P. (1990) The Nutritive Value for Ruminants of Tagasaste (Chamaecytisus palmensis), a Leguminous Tree . Animal Feed Science and Technology, 28, 275-292.
Getnet Assefa (1998) Biomass yield, botanical fractions and quality of tagasaste, (Chamaecytisus palmensis) as affected by harvesting interval in the highlands of Ethiopia. Agroforestry Systems, 42, 13-23.
Snook, L.C. (1982) Tagasaste (tree lucerne): a shrub with high potential as a productive fodder crop. Journal of the Australian Institute of Agricultural Science, 48, 209-214.
Townsend, R.J. and Radcliffe, J.E. (1990) Tagasaste forage production systems.  New Zealand Journal of Agricultural research, 33, 627-634.
Varvikko, T. and Khalili, H. (1993) Wilted tagasaste (Chamaecytisus palmensis) forage as a replacement for a concentrate supplement for lactating crossbred Friesian x Zebu (Boran) dairy cows fed low-quality native hay . Animal Feed Science and Technology, 40, 239-250.

Internet links

Cultivars

Cultivars

Country/date released

Details

None released to date.          

Promising accessions

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Promising accessions

Country

Details

ILRI 15378 Ethiopia Tolerant to acid soils and produces edible biomass yields of about 6 t/ha after 1 years growth.