Agroforestree Database

Local names:
 Arabic (mesquite), Creole (bayawonn,bayawonn fran), English (ironwood,algarroba,honey mesquite,mesquite,mesquite bean), Filipino (aroma), French (bayahonda,chambron,bayarone,bayahonde francais), German (mesquitebaum), Hindi (vilayati khejra,vilayati babu

Prosopis juliflora is an evergreen tree with a large crown and an open canopy, growing to a height of 5-10 m. Stem green-brown, sinuous and twisted, with axial thorns situated on both sides of the nodes and branches. Bark somewhat rough; dull red. The root system includes a deep taproot. 

Leaves compound; leaflets in 13-25 pairs, oblong (3 x 1.7 mm) and dark green, bipinnate with 1 or sometimes 2 pairs of rachis, almost pendulous. 

Flowers latteral to the axis with a tubular, light greenish-yellow, 1.5 mm wide calyx with hooded teeth; corolla light greenish-yellow, composed of 5 petals with 3 mm wide pubescent along its edges.

Fruit a non-dehiscent pod, straight, linear, falcate to annular, with a coraceous mesocarp in 1 segment or divided into several segments; seeds compressed, ovoid, hard, dark brown, with mucilaginous endosperm surrounding the embryo; cotyledons flat, rounded, epigenous when germinating.

Ecology

P. juliflora is xerophytic and is adapted to many soil types under a wide range of moisture conditions. The value of the tree lies in its exceptional tolerance of drought and marginal soils. It tolerates strongly saline soils and seasonal waterlogging. P. juliflora has been planted successfully on soils with acid to alkaline reaction. It is sometimes said to dry out the soil and compete with grasses, particularly in dry areas; hence in some areas it is considered a weed.

Native range
Argentina, Belize, Bolivia, Chile, Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Peru, United States of America

Tree management

The tree normally grows to a height of about 10 m, but under favourable conditions it may reach 20 m. Spacing depends on the use intended for the trees. In South America when grown for fuelwood, a spacing of 2 x 2 m or wider is used. In rangeland in association with grasses and other crops, the spacing may be up to 10 x 10-15 m. When the emphasis is on pod production, the spacing used is usually 5 x 5-10 m. Young plants benefit from weeding around the stem and need protection from grazing animals. Thinning and pruning are needed to prevent P. juliflora from becoming a weed and to keep the plantation accessible. P. juliflora coppices readily. Because of its aggressive nature, it is considered a noxious weed in more humid areas, e.g. the southern USA.

Seed storage behaviour is orthodox; 60% germination following 50 years storage; viability can be maintained for several years in hermetic storage at 10 deg. C with 5-9% mc; no loss in viability following 24 hours of immersion in liquid nitrogen for seeds at 7% mc and 5% mc. There are 20 000-26 000 seeds/kg.

P. juliflora is xerophytic and is adapted to many soil types under a wide range of moisture conditions. The value of the tree lies in its exceptional tolerance of drought and marginal soils. It tolerates strongly saline soils and seasonal waterlogging. P. juliflora has been planted successfully on soils with acid to alkaline reaction. It is sometimes said to dry out the soil and compete with grasses, particularly in dry areas; hence in some areas it is considered a weed.

Propagation is by seed, root cuttings or grafting. Establishment by seed is feasible, although seed is difficult to extract from the pods. Pretreatment is either by soaking for 15-20 minutes in sulphuric acid followed by thorough washing in cold water or by mechanical scarification; 80-90 % of the seeds germinate in 4-6 days. Aerial seeding is applied successfully to quickly cover remote, extensive and poorly accessible areas. Inoculation with Rhizobium and mycorrhizal fungi is advantageous.

Widely planted for land reclamation because it is an aggressive colonizer, tolerant of very poor, degraded, saline and alkaline soils. In the USA, aerial seeding of a mixture of P. juliflora, Nicotania glauca and several Eucalyptus species is used to revegetate abandoned copper mines.

Erosion control:  P. juliflora has been used to arrest wind erosion and stabilize sand dunes on coastal areas. It is listed as on the tree species used in sand-dune stabilization in India.

  A rich, delicious flour can be made from pulverized pods from which seeds have been removed. Cotyledons and embryos when pulverized yield a flour rich in protein and sugar appropriate for diabetic people. There are reports that P. juliflora pods are used in preparing bread, sweets, syrup and coffee. The pods must be processed to improve the flavour. Sugars and sweeteners can be produced from the pods.

For dairy cows, the flour may make up 40-60% of concentrate rations. In South Africa, it is fed unmixed to sheep. Ripe pods contain 12-14% crude protein. The short-fibred parts are also suitable for pigs and poultry.

Apiculture:  This species is a major honey source in Bolivia, Jamaica, Pakistan, western Australia and elsewhere. In Sri Lanka, it is one of the most important species for bee forage due to its very copious nectar flow.

The generally crooked stems and branches make good firewood and provide excellent charcoal. Charcoal from P. juliflora wood is used extensively in the USA as barbecue fuel; about 30% of the charcoal sold for this purpose originates from P. juliflora from the Sonora Desert in northern Mexico.

Fibre:  There is a large potential for P. juliflora as a source for fibre in the production of paper, paperboard and hardboard. 

Timber:  Seasoned wood is used for fence posts, furniture, crafts and corrals. It is rarely used in construction, as most tree trunks are not long or straight enough. 

Shade or shelter:  Planted in windbreaks and shelterbelts. 

Tannin or dyestuff:  Tannin or dyestuff can be extracted from P. juliflora but the yield is only about 10%. Tannin could also be extracted as a byproduct when P. juliflora wood is processed for other purposes, such as animal rations.

Medicine:  P. juliflora syrup prepared from ground pods has various medicinal values. It is given to children showing weight deficiency or retardation in motor development, the syrup is believed to increase lactation. It is also used for preparing various medicinal syrups, particularly for expectorants. Tea made from P. juliflora is thought to be good for digestive disturbances and skin lesions.

Gum or resin:  P. juliflora heartwood contains significant amounts of extractable polyphenolic compounds from which can be isolated a unique flavinol compound used in the formation of new phenol-formaldehyde polymeric resins. A reddish-amber gum, similar 

Nitrogen fixing:  P. juliflora moderately enriches the soil with atmospheric nitrogen obtained through symbiosis with cowpea-type Rhizobium. The roots also form mycorrhizal associations with Glomus fungi. Plants with both Rhizobium and mycorrhizal associations show significantly higher nitrogen fixation rates than those lacking the mycorrhiza. 

Ornamental:  P. juliflora is used to line urban motorways. However, its thorns pose problems for pruning and maintenance.

Soil improver:  Total nitrogen, sulphur and soluble salts, as well as organic matter, have been shown to increase 3-fold in the upper 4.5 m of soil under P. juliflora. 

Intercropping:  The best species to grow in association with P. juliflora are Cenchrus ciliaris, Opuntia spp. and Pancium maximum. 

Alcohol:  In Argentina, Chile and Peru the pods are an important item in making alcoholic drinks such as cocktails.