Prosopis tamarugo , a tree that grows in the Atacama desert in Chile and is 15 m tall, occasionally reaches 18 m, hanging or with an irregularly shaped balloon crown.
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- 1 Origin and Distribution
- 2 Features
- 3 Development
- 4 fruits
- 5 Use
- 6 Nutritional value
- 1 Chemical compounds
- 7 Reproduction
- 8 Pests that affect you
- 9 Source
Origin and Distribution
Originally from the north of Chile, P.Tamarugo can be planted in areas with a salt layer between 10-60 cm, it can grow in calcareous or sandy soils, it has a particular physiology. Under conditions of high atmospheric humidity above 80%, plants absorb water through the leaf system, transport it throughout the root system, and deposit it in the micro-microsphere , where it can be absorbed as water, Sudjuka 1985 .
This explains its adaptation to places where the water is 40 m deep. It is the most important species in the north of Chile , in the province of Tarapacá , the only species of the arid plateaus, without rains, in the Atacama desert, which cover around 15,000 km2 also in the central strip of Tarapacá, north of Chuquicamata and southern Arica , in scattered stands. It grows well in salty, undulating soils from 750 to 1,100 masl
These plants are distributed in a larger area with tamarugo found in the Pampa del Tamarugal National Reserve , with an area of about 100,000 ha, of which around 20,550 ha are plantations made in the last 30 years.
It forms sparse forests, with densities of 1 to 20 trees per hectare , or in more or less dense small stands. It is often accompanied by trees and shrubs such as: Prosopis alba, Atriplex atacamensis, P.strombulífera, P.burkartii and Tessaria absinthioides.
The Tamarugo helps the planting of the soil, and as it is a legume it contributes nitrogen to the soil, increasing its fertility. In the past, the indigenous people of the northern zone reforested with Tamarugo.
It is a tree that generally grows in the Hemisphere , occurs throughout the year, being maximum in the months of August to November; that is, at the time of full bloom and minimum growth between March and July , autumn – winter .
The Tamarugo has a double root system: a pivoting or anchoring system, consisting of 3-4 thick, unbranched roots, which reach a maximum depth in loamy soils of 7 to 8 m and a set of absorbent roots that develops and penetrates to one depth not greater than 1.50 m. The absorbing roots featured throughout the projection volume moisture easily reaches 40% according to measurements made in the field of Refreshment, in September of 1966 and January of 1976 in trees 30 years old, thriving on a floor whose napa water table was 13 m deep. They are tolerant to drought, high pH, salt and sandy soils; Habit 1981 .
It is a tree 15 m high, occasionally reaching 18 m, hanging or with the crown as an irregularly shaped balloon; the cleft bark, dark gray; the arched and gnarled branches, flexuous twigs, reddish-brown, spines in pairs, axillary 0.5-3.8 cm long, stipules at the reddish-brown origin; the leaves are often bipinnate, with 6-15 pairs of leaflets, the flowers in cylindrical, yellow-golden bunches. Sessile , calyx 1.5 mm corolla 4-5 mm long. Petals joined, with the fuzzy end inwards. Downy ovary.
For its proper development, this tree requires very high solar radiation and the presence of superficial and medium depth water tables (2-15m), which constitute its main source of water supply .
The following environmental characteristics are those corresponding to its place of origin: the low climate in which it grows corresponds to the Interior Desert, which stands out for very severe conditions. There is an almost absolute lack of precipitation (0.2-1mm / year) and a large daily thermal oscillation is present, reaching up to 35 ° C. The species tolerates extreme temperatures and withstands strong winds. Night fogs are often present, the relative humidity of the air shows great daily variations, especially between September and March, when it reaches an average of 3-10% in the day to reach 80-100% at night. Daytime cloudiness is almost nil and there is high solar radiation (550cal / cm2 / day).
In the highlands, rains can occur during the two warmest months (December and January) and during the coldest winter period (June-August). These precipitations are usually sporadic, occurring torrentially with 130-300 mm every 5-6 years. These summer rains of marginal tropical origin are effects of the high plateau winter of the extreme north of Chile and Bolivia . They favor the recharge of the groundwater of the Pampa del Tamarugal located below and facilitate natural regeneration by seeds .
Under desert conditions the rains can become harmful; since they can filter the superficial saline crusts and bring the salinity to the root zone, increasing the difficulty of the extraction of groundwater .
The soils 100-106 cm deep, with little surface stoniness, are made up of fill materials of fluvial origin, coming from the Andes Mountains . They can be sandy, saline or clay loam, with good drainage, often with superficial salt inlays of calcium sulfate and sodium chloride , 10 to 60 cm thick. The pH ranges from 8.0 to 8.4. Groundwater can be found from 1 to 15m deep and even up to 60m or more. The salinity of the water ranges from 5-30 g / l.
Its fruit is coriaceous , fleshy, ring-shaped, very curved, often solitary, falcate reddish-brown, green-yellowish or yellow straw; between 2.5 and 4 cm and 0.7-1 cm thick; printed sutures, particularly on the concave side; the subapical apex is short and with a round base of 1 mm in length.
Of sub-cylindrical section; epicarp 0.5-1.5mm thick; thick, reddish-brown mesocarp, which dries when ripe; 5-22 segmentations, transverse in two irregular rows and separated by the mesocarp, containing 7-18 seeds inside, submerged in a brown pulp. The seeds are light brown to dark brown, smooth and more or less compressed, 3.8-5.2 mm long by 2.6-3.2 mm wide and 1.1-1.4 mm thick . The fissure line formed like an open horseshoe, and asymmetric on the seed faces.
The chalaza ends externally and obliquely, located towards the dorsal suture of the seed; the subapical thread ends in a slight depression and the shaved raphe is grayish. It has an elliptical, triangular section with dull and thin edges. The testa is very thick, with the tegmen somewhat thicker and lighter in color than the testa; the endosperm is abundant, hard and asymmetric on both sides of the cotyledons , which are slightly yellow, flat and sagittal at the base but not completely surrounding the upper part of the radicle.
Tamarugo has been shown to protect groundwater reserves, lessen the effects of wind on the desert, moderate local temperatures, provide shade for animals, accumulate biomass for energy, and provide recreation opportunities for local populations. The plantations made with Tamarugo, as well as the natural forests, have meant the transformation of the absolute desert ecosystem into an agro-ecosystem and the opening to the social and economic development of the area. Tamarugo productivity is related to the age, planting distance, depth and quality of the water table; Likewise, the initial management observed in the plantations has an impact on productivity. the pests and its treatments also have a marked incidence.
Fruiting occurs uniformly in the tree canopy; the fruits when falling are distributed on the ground, with a higher density in the projection of the tree. Apparently, the performance does not vary considerably. It reports a control carried out in 1957 on 19 trees, in this one an average weight of 2.10 kg of fruits per m2 was obtained in the projection of the tree canopy; likewise, in 30-year-old trees, the average fruit and leaf litter per square meter in the projection of the tree canopy; observed a yield of 3.40 Kg / m2 of dry matter. In 18-year-old trees the average was 1.8 Kg / m2 of dry matter.
This tree produces abundant forage desired by sheep , cattle and goats , with 12% crude protein, 30% fiber and 1.9% ethereal extract, the digestibility of the fruit being protein, 13.98%; 1.16% ether extract; free nitrogen extract, 28% and total digestible nutrients, 50.58%.
Tamarugo is a good food, since it contains approximately 5% of digestible crude protein and the total of digestible nutrients reaches 55%. The relatively low value of the tamarugo fruit in terms of total digestible nutrients should not be interpreted as an index of low nutritional value, since these values are relatively comparable to the values of a concentrated food.
The carbohydrates and the proportion of fiber are adequate and are included in its composition, sufficient fats so that the sheep and goats do not suffer, it establishes that the studied forages can be classified as coarse material, whose fiber volume is high, particularly the fruit , suggests that they be complemented with other forage to constitute a balanced diet for the sheep and the goat during the most demanding periods (late pregnancy and early lactation).
These fruits are composed of: each 100 gs of fruits contains: 3.34g of water, 11.14 g of protein, 1.26 of fats, 79.63 of total carbohydrates, 31.45 of fiber, 4.27 of ashes , 280mg of Ca, 1,440mg of P.
This tree reproduces by seeds that maintain viability for up to 15 years or more. The number of seeds per kg ranges from 79,000-110,000. A kg of fruits or pods provides between 70-156 g of pure seeds.
- Seed collection: Producing trees are marked according to their phenotypic characteristics; the fruits are collected from October to January, proceeding to clean them mechanically and then grinding them in a stone mill 4 mm apart; later, by screening and flotation, the clean seed is obtained. The seed is treated with sulfuric acid for seven minutes in order to produce wear on the cuticle and facilitate gas exchange and water penetration through the only micro-opening in the seed. This produces the rehydration of the colloids and the germination process begins.
- Nursery: A mixture of soil and sheep’s guano is prepared in a ratio of 2: 1. Plastic bags are filled, without holes, 12 cm in diameter by 30 cm in length, which act as flowerpots. Sowing is done with 3 to 5 seeds per bag at a depth of 1.5 cm.
- Regarding irrigation, it is important to keep moist the superficial part where the seeds are located, without producing water accumulation, to avoid infestation with fungi . Before sowing, it is convenient to treat the soil with specific fungicides or fumigants such as methyl bromide , in order to avoid any pathogen at the beginning of the germination process and early stages of seedling development.
Once the seed has germinated and the seedling has emerged , it is watered with more water but with longer time intervals, ensuring the supply of moisture to the root that grows in depth. It is essential to inoculate when not in-situ. The seedling remains in the nursery for 3 to 5 months, until it reaches a height of 8 to 10 cm. Since root development is fast and vigorous, roots must be prevented from passing through or breaking the plastic bag .
- Planting: The following planting systems are used: 10 x 10m and 15 X 15m square and triangulation. The planting hole is about 30 cm in diameter by 40 or 50 cm deep, it can be done manually or mechanically. In the first case, they may have a larger diameter due to the process of removing superficial saline crusts; in the second case, the operation is executed with a caterpillar tractorwith a special design front shovel, which leaves a kind of trench 80 cm wide by one meter long at its base. When carrying out this operation, the “agricultural” or “sweet” soil is reached, as it is also called. The depth of the cup depends on the terrain; it is generally 80 cm in diameter in relation to the depth of the salt crust, which must be exceeded before making the planting hole. Once the soil has been discovered, the hole is made, which is 30 cm deep by 20 cm in diameter, being made manually or by means of a mechanically actuated drill hole. Before planting, a saturation irrigation is given to the planting hole, in order to moisten it as deeply as possible.
- Irrigation: for plants to establish themselves normally, the amount of irrigation water must be sufficient to penetrate to the root sector, keeping the area moist. The number of establishment irrigations according to the conditions of the phreatic level and humidity depth, will vary considerably. On average, it can be calculated that 11 irrigations are applied during the establishment period. The establishment of the plant is characterized by the emission of new shoots, and when this happens, the irrigation can be 20 days apart.
The most important thing is to avoid an excess of water, which is reflected in the first stage of the seedling with a fall due to fungus , and when it is more grown, due to a yellow color of the leaves. In planting costs, one of the most important items corresponds to the value of the irrigation. One of the ways of reducing the number of irrigations is to reduce the evaporation of irrigation water by using plastic in the planting hole, and another by means of a slower supply of water (dripping), which allows better use.
Pests that affect you
They are affected by insects and mites that damage the foliage and twigs: Leptotes trigemmatus , lepidoptera (purple moth); Tephrinopsis memor, lepidoptera (measuring worm), Leaf-glue, microlepidopter; Hemiberlesia rapax, homoptera ; Heteropysylla texana, homoptera ; Aphis sp, homoptera (Tamarugo’s aphid); Cecidomid , diptera . Inflorescence-destroying insects: Ithome sp, lepidoptera (flower moth); Leptotes trigemmatus; Tephrinopsis memeor, lepidoptera ; Franhiella rodeos , thysanoptera(trips of the Tamarugo); that damage the fruit and the seed: Crytophlebia carpophagoides, lepidoptera (fruit moth); Leptotes trigemmatus , lepidoptera ; Scutobruchus spendingi , coleoptera (bruco del Tamarugo):
The three species considered of greatest importance are the flower moth , the violet moth and the fruit moth . The first two present several generations at the critical time, on the other hand, it is believed that the third has only one generation, since it is observed that their larvae, after the last larval stage, go into a state of diapause that lasts until the beginning of the next season. The damage caused by the flower moth and the violet moth is very important and can reach up to 52%. Pollinating insects, autochthonous or native pollinators: Centrix mixta . Introduced pollinators: Apis melífera .