Almond tree characteristics, habitat, cultivation, varieties

2890
Basil Manning

The almond(Prunus dulcis) is a deciduous tree that belongs to the subgenus Amygdalus of the Rosacea family and the Rosales order. Native to Asia Minor and feral in the Caucasus and Greece, it adapts to the agro-climatic conditions of the Mediterranean.

This species is a medium-sized tree with deep roots, a sinuous trunk, hard wood and an irregular crown. The leaves are oblong and slightly serrated, the five-petal flowers are white or pink, its fruit being the traditional almond.

Almond Tree (Prunis dulcis). Source: צילום: דור אבישי טייכר [CC BY 2.5 (https://creativecommons.org/licenses/by/2.5)]

The cultivation of the almond tree is carried out primarily by its seed, rich in fatty acids, vitamins, amino acids, mineral elements and proteins. In fact, the largest almond producers worldwide are the United States, Spain, Australia, Tunisia, Iran, Morocco, Syria and Turkey..

There is a great diversity of varieties that are distributed according to their adaptation to certain climatic conditions. Likewise, these varieties can be organized into two large groups, one of "soft shell" and the other of "hard shell".

The almond is the edible fruit of the almond tree, and is consumed fresh, roasted, cooked or smoked, being the ideal complement to various traditional dishes. They are widely used in confectionery to make nougat, cakes, marzipan, sweets, caramelised and candied almonds.

On the other hand, an oil used exclusively in cosmetology is extracted from the almonds, as well as a milk with a high protein content called "almond horchata". In addition, the firm and reddish wood is used in cabinetmaking, the cover of the fruit is used as fodder and the peel as a food additive.

Article index

  • 1 General characteristics
    • 1.1 Plant
    • 1.2 Flowers
    • 1.3 Fruits
    • 1.4 Phytochemistry
  • 2 Taxonomy
    • 2.1 Etymology
    • 2.2 Synonyms
  • 3 Habitat and distribution
  • 4 Cultivation
    • 4.1 Requirements
    • 4.2 Propagation
    • 4.3 Handling
  • 5 Diseases
    • 5.1 Dent or leprosy
    • 5.2 Dry bud
    • 5.3 Screening or shotgun
    • 5.4 Ocher stain
    • 5.5 Bacterial stain
    • 5.6 Moniliosis
    • 5.7 Rust
  • 6 Varieties
    • 6.1 American ecotype
    • 6.2 Spanish ecotype
    • 6.3 French ecotype
    • 6.4 Italian ecotype
    • 6.5 Tunisian ecotype
  • 7 References

Characterígeneral statistics

Plant

Prunus dulcis It is a deciduous tree 4-10 m high with a woody and sinuous trunk, with rough, dark bark and easy to tear. Simple leaves 10-12 cm long are lanceolate, petiolate, slightly scalloped margin and green on both sides..

flowers

The flowers are arranged solitary or grouped in three units, white or slightly pinkish. Each flower consists of 5 petals and 5 free sepals of reddish color and tomentose margin, it also contains numerous reddish stamens and bracts.

Details of the Almond blossom (Prunis dulcis). Source: י.ש. at Hebrew Wikipedia [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)]

Flowering occurs at the beginning of spring, even if the weather is favorable, it blooms from January and February. The almond trees present an entomogamous pollination, that is to say, they depend on insects for their pollination; they have showy flowers and abundant nectar that attracts insects.

Fruit

The fruit is an indehiscent nut or nut, ovoid or oblong, 30-50 mm long, velvety and greenish-gray in color. The almond covered by a hard and porous endocarp, takes approximately 8 months to mature after flowering.

Depending on the variety, bitter or sweet almonds are obtained, with a flavor ranging from bitter and dry to smooth and milky. The difference between both varieties is in the taste and size, since the bitter ones are slightly larger..

Sweet almonds are those that are traditionally marketed as dried fruit, and includes the hard-shelled and soft-shelled varieties. In contrast, bitter almonds have only the hard shell.

Phytochemistry

Chemical analysis of almonds reports 20% proteins and 40-55% oils or monounsaturated and unsaturated fatty acids. As well as fibers, mucilages, emulsin, calcium, phosphorus, iron, magnesium, potassium, zinc, vitamin E, niacin, riboflavin, thiamine, and folic acid.

Taxonomíto

- Kingdom: Plantae

- Division: Magnoliophyta

- Class: Magnoliopsida

- Subclass: Rosidae

- Order: Rosales

- Family: Rosaceae

- Subfamily: Amygdaloideae

- Tribe: Amygdaleae

- Gender: Prunus

- Subgenre: Amygdalus

- Species: Prunus dulcis (Mill.) D.A. Webb

Etymology

- Prunus, generic name that comes from the Greek "προύνη"and from Latin"prūnus", referring to the wild plum.

- dulcis, specific epithet derived from Latin "dulcis-e", which means sweet, pleasant or delicious, for its fruit with a pleasant taste and aroma.

Ripe almonds. Source: באדיבות אתרצמח השדה [CC BY 2.5 (https://creativecommons.org/licenses/by/2.5)]

Synonyms

- Amygdalus dulcis Mill.

- Prunus amygdalus (L.) Batsch

- Amygdalus communis L.

Habitat and distribution

Prunus dulcis It is native to central and southwestern Asia where it is found in the wild throughout the mountainous areas. In fact, it is common in the Tain Shan mountains and Kurdistan, up to Afghanistan, Turkestan, Mesopotamia and Persia..

There is written evidence of its cultivation from 350 BC. On the other hand, it is presumed that its origin is due to the crossing between wild species Prunus bucharica Y Prunus fenzliana.

Its dispersion through the Mediterranean basin was thanks to the intervention of the Arabs, Phoenicians, Greeks and Romans. The Phoenicians brought their seeds from the East, the Greeks and Romans cultivated it, and the Arabs completed their expansion during the 7th century..

In Spain the almond tree has been cultivated for 2,000 years, introduced by the Phoenicians and propagated by the Romans. In the middle of the 18th century it was taken by the Franciscan friars to the missions of the New World, specifically to California.

It is naturally found in Southeast Asia and North Africa. As a commercial crop, it is found in Spain, Portugal, France and Italy, as well as a foreign species in California, southern Africa and Australia..

Unripe fruits on an almond tree. Source: 3268zauber [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)]

In Spain it is produced as a crop for agricultural use in regions outside the Mediterranean, Andalusia, Murcia, the Valencian Community, Catalonia and the Balearic Islands. However, in the central or northern region, it is planted as an ornamental crop, since the strong winter limits the ripening of the fruits..

This crop adapts to the warm Mediterranean climate, between 30º-40º latitude North and South, and mild and humid winters. In fact, it supports intense cold down to -20º C at rest, hot and dry summers with rainfall less than 600 mm..

Culture

Requirements

The cultivation of the almond tree adapts to typically Mediterranean climates, being resistant to hot summers and cold winters. In addition, it supports prolonged periods of drought, and adapts to sandy, limestone, dry soils of low fertility..

The best crop productivity occurs in dry and warm temperate climates, loose, deep, fertile soils with a neutral pH. Indeed, it requires an average depth of one meter and altitude levels between 100-2,000 meters above sea level, with 1,000 meters being the optimum elevation..

Spread

The almond tree reproduces sexually from seed, or vegetatively through grafting. Propagation by seed is the usual method to achieve vigorous and leafy trees, being the appropriate technique to keep the local varieties active..

In addition, the use of seed from healthy and strong plants makes it possible to produce frank rootstocks for the vegetative reproduction of highly productive varieties. The rootstocks are obtained from both bitter and sweet almonds, the most common being GF 677 and PS A6.

The GF 677 rootstock adapts to a wide variety of soils and environmental conditions, induces vigor, accelerates flowering and increases productivity. PS A6 guarantees fast flowering, but is less resistant to drought and is sensitive to fungal attacks.

In commercial farms the recommended planting spacing is the sixth 6 x 6 m between plants and rows. This provision favors the implementation of intensive and agro-ecological production techniques, as well as the mechanization of handling and harvesting..

Almond blossoms. Source: pixabay.com

Driving

During the flowering period the almond tree requires protection against spring frosts that affect the production and ripening of the fruits. In fact, the use of resistant varieties, physical methods (smoke or fog) or natural products based on non-ionic surfactants is recommended..

The almond tree in its growth, flowering and fruiting phases is sensitive to strong winds. It is recommended to establish the cultivation in areas with natural barriers or forest shields in order to avoid damages that condition its development..

Fertilization is essential to achieve maximum productive performance, being necessary to incorporate adequate amounts of nutritive elements based on soil analysis and foliar analysis..

The water supply through irrigation should not exceed the limits required by the crop, otherwise it could cause physiological damage. Likewise, in conditions of high rainfall the crop is prone to acquiring fungal diseases.

Pruning allows the formation or sanitation of the crop; This is how the training pruning allows to control the vegetative development of the plant. On the other hand, regeneration pruning allows aging branches to be rejuvenated and invigorated, in order to maintain their productive level..

Buds of almond flowers. Source: 4028mdk09 [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)]

Diseases

Under certain conditions of high temperature and humidity, almond trees are prone to attack by fungi or phytopathogenic bacteria. Among the main diseases are dent, dry bud, screening, ocher spot, bacterial stain, moniliosis and rust.

Dent or leprosy

Disease that affects leaves and fruits in high rainfall conditions whose causal agent is the ascomycete fungus Taphrina deformans. The leaves swell and deform, and the shoots become discolored, the preventive treatment being the application of systemic and contact insecticides..

Dry bud

Disease known as "dry" of the almond tree caused by the fungus Phomopsys amygdali, and appears through wounds after defoliation. The best control is the preventive measures with cicatrizing, the disinfection of the pruning material and the elimination of diseased branches..

Screened or shot

Disease that affects the bark, leaves and fruits of the almond tree, caused by the imperfect fungus Stigmina carpohyla in high rainfall conditions. The symptoms are rubbed spots that dry and detach, leaving a hole, being controlled through sanitation pruning or preventive fumigations.

Ocher stain

The symptoms are ocher-colored spots at the level of the leaves, which causes the subsequent defoliation of the tree. The causative agent is the fungus Polystigma ochraceum, being its chemical control applying products such as capturing or eliminating infected leaves.

Characteristic symptoms of ocher stain (Polystigma ochraceum) Source: Luis Fernández García [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]

Bacterial stain

Bacterial disease caused by Arboreal Xanthomonas pv. Pruni, its highest incidence occurs in conditions of high humidity. Control is the total eradication of the plant once the disease has been confirmed according to laboratory analysis.

Moniliosis

Symptoms appear on flower buds, causing wilting of flowers, as well as cankers at the level of leaves and branches. The causal agent is Monilinia laxa, its control is preventively using fungicides during and after flowering.

Rust

Disease promoted by the fungus Tranzschelia pruni-spinosae in high humidity conditions, it causes circular spots on the leaves covered with a red-yellowish powder. The recommended control measures is the application of contact preventive fungicides and elimination of contaminated branches..

Varieties

The almond tree has a large number of varieties depending on the geographical areas and the climatic conditions of each region. This diversity has favored its great variability creating very dissimilar ecotypes, but with some common characteristics..

American ecotype

Types of almond trees derived from the "Non Pareil" variety characterized by a homogeneous, thick, elongated almond with light and smooth skin. Materials of this type have common features such as medium flowering time and soft shell..

Spanish ecotype

In this type, a group of varieties of very early or early flowering season with hard-shelled almonds stands out. Among these varieties stands out the "Desmayo Largueta" native to the Ebro Valley, made of elliptical-amygdaloid almonds of excellent appearance and taste quality..

These varieties are adapted to medium altitude levels, between 300-750 meters above sea level. In addition, the skin of the fruits is easily separated, so they are adapted to be roasted and for baking.

On the other hand, the "Marcona" variety, native to the province of Alicante, stands out, known as the classic almond, with early flowering and quality fruits. Almonds are rounded, with a high content of fatty oils, with a hard shell, used especially for nougats, sweets and snacks.

Almonds Source: pixabay.com

French ecotype

They are generally very late-flowering almond trees, but they have an early ripening period. They are characterized by having a single flower per bud and do not produce double almonds; the main varieties include "Flour en Bas", "Aï" and "Tardive de la Verdière".

Italian ecotype

It is a group of late-flowering almond trees with a hard shell consistency, with a large number of double almonds per fruit. Among these varieties of self-compatible or self-fertile character, cylindrical fruits and short amygdaloid, "Genco", "Tuono" and "Filippo Ceo" stand out..

Tunisian ecotype

Typical varieties of the Sfax regio on the Tunisian coast, with dry climates and mild winters that promote very early flowering. They are varieties of precocious maturation, grains with high lipid content and few double almonds, the varieties "Achaak" and "Zahaf" stand out..

References

  1. Almond. (2019). Wikipedia, The Free Encyclopedia. Recovered at: es.wikipedia.org
  2. Caring for the Prunus dulcis or Almendro plant (2019) Plant sheets with their care since 2001. Retrieved from: consultaplantas.com
  3. Fernández M., A. V. (2010). Self-compatibility in the almond tree (Prunus amygdalus Batsch): genetic structure of the Sf allele and modifications of its expression (Doctoral dissertation, Centro de Investigación y Tecnología Agroalimentaria de Aragón).
  4. Lavín, Arturo & Silva, Reina (2001) Fruit trees for the Interior Drylands. INIA Bulletin Nº 30. Behavior of Carozos and Pomáceas. Cauquenes Agricultural Research Institute, Chile. ISSN 0717-4829.
  5. Morales Valverde, R. (1999). Ethnobotany: Almond blossoms.
  6. Mori, A., Lapsley, K., & Mattes, R. D. (2011). Almonds (Prunus dulcis): Post-Ingestive Hormonal Response. In Nuts and Seeds in Health and Disease Prevention (pp. 167-173). Academic Press.
  7. Navarro Muñoz, A. (2002). The almond tree: varieties and cultivation techniques. Junta de Andalucía, Ministry of Agriculture and Fisheries, Andalusia (Spain).
  8. Prunus dulcis. (2019). Wikipedia, The Free Encyclopedia. Recovered at: es.wikipedia.org
  9. Prunus dulcis (2018) Argentine National Pest Surveillance and Monitoring System. Recovered at: sinavimo.gov.ar

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