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As soon as the word “almond” is heard, some people imagine delicious nuts with a characteristic shape, while others imagine a small tree covered with a cloud of soft pink flowers. Children know Raffaello sweets, and adults know Amaretto liqueur, the indispensable ingredient of which is the aromatic kernel of the seed, which is not actually a nut. Unfortunately, almonds do not grow everywhere. Our only edible species is cold, but through the efforts of breeders, the crop is gradually expanding into cool regions.
Are almonds an apricot kernel or not?
Some people believe that apricot kernels are almonds. This is a misconception, and a dangerous one at that. Apricot kernels, like almond kernels, contain amygdalin, which releases hydrocyanic acid when broken down. True, the concentration of poison in the kernel is low, and during heat treatment it is significantly reduced, but it can still cause harm to the body, especially children.
Apricots are grown for their juicy fruits; the pits are supposed to be discarded before consumption. Therefore, breeding is aimed at developing varieties with diverse pulp characteristics, and no one is working to reduce the concentration of cyanide compounds in the kernel.It is enough that they do not turn into fruits.
Almonds, as a fruit tree, are planted exclusively for the production of kernels, mistakenly called nuts. Over thousands of years of selection, the concentration of amygdalin in them has been reduced to a minimum.
It is impossible to confuse an apricot pit and an almond pit. In the latter, it is similar to peach, although usually smaller in size, and covered with deeply depressed dots and strokes. If you compare the apricot and almond seeds in the photo, the difference is clearly visible:
Where do almonds come from?
The subgenus Almond belongs to the genus Plum of the Rosaceae family and consists of 40 species. Only one of them is edible - the Common Almond (Prunus dulcis). It is its cultivated trees that produce seeds, the kernels of which are eaten. They are called almond nuts, and although this is incorrect from a botanical point of view, the name has stuck.
Species trees produce seeds with bitter kernels containing large amounts of amygdalin (2-8%). They are widely used in the perfume industry and for the manufacture of medicines; only a small part is used by the food industry to give products a characteristic taste and aroma.
The kernels of the species plant are commonly called bitter almonds (Prunus dulcis var. Amara). Sometimes they are considered inedible, but this is not true. You can eat bitter almond kernels, although in small quantities. It is believed that the lethal dose for children is 5-10 “nuts”, for adults – 50. But, if you consider that even sweet almonds are recommended to eat no more than 10 kernels per day, everything turns out to be not so scary. In addition, heat treatment significantly reduces the concentration of amygdalin in the bones.
Cultivars that have been bred over thousands of years to reduce bitterness are called sweet almonds (Prunus dulcis var. Dulcis). The concentration of amygdalin in it does not exceed 0.2%. It is these seeds, or shelled kernels, that are sold in markets and supermarkets.
Based on this, we can conclude that edible almonds are divided into two groups:
- bitter, that is, the species plant and its forms;
- sweet - artificially bred varieties with a kernel containing a low concentration of amygdalin.
Where do almonds grow?
Common almonds have been grown for so long, and the crop itself has proven so attractive for cultivation in hot, arid climates, that scientists can only guess where it comes from. Most botanists agree that the primary source of occurrence of the species is in Western Asia. The almond tree is mentioned in the Bible; from later sources, the “Book of One Thousand and One Nights” should be noted, the roots of which go back to ancient times, and the origin has not yet been clarified.
Cultivated tree plantations covered the territory of Ancient Greece and Rome in the Mediterranean, Tunisia, Algeria, Morocco in Africa. In the Fergana Valley, there is the “city of almonds” Kanibadam (Tajikistan). In addition to the Central Asian countries - Uzbekistan, Kyrgyzstan and Tajikistan, the culture is widespread in Armenia, Dagestan and Georgia, where the trees came from Persia, China, Iraq, Turkey and Afghanistan.
Today, almond trees are grown in Chile and Australia, in Central and Asia Minor, southern Europe and northern Africa. But the largest industrial plantations are in the state of California. It is the United States that is the world's largest exporter, where in 2018 the production of cores reached 1.1 million tons, and the supply to the foreign market was about 710 thousand tons. They are followed by Spain, Iran, Italy, Morocco and Syria by a wide margin.
Sweet almond trees grow in the Caucasus and Crimea. All 8 varieties included in the State Register were created in the Nikitsky Botanical Garden. Selection is aimed at breeding trees that can withstand low temperatures, recurrent frosts and soil moisture that exceeds what is usual for the crop.
Ornamental trees
In addition to edible varieties, there are ornamental trees and shrubs. They also love warmth, but can grow in regions with much harsher climates. For use in landscape design, varieties are bred by crossing the following species with Common Almond:
- Steppe, Low or Bobovnik grows under natural conditions in South-Eastern and Central Europe, Western Siberia and Central Asia. It can be cultivated near Vologda and St. Petersburg.
- Georgian – promising for landscaping, less frost-resistant than the previous species, endemic to the Caucasus. Can grow in the Moscow and Leningrad regions.
- Ledeboura, whose habitat is the foothills of Tarbagatai and Altai. Showed sufficient frost resistance in Belarus, Moscow and Leningrad regions. Often used to create varieties and hybrids.
- Petunnikova - a fairly winter-hardy endemic of the western Tien Shan. Grown in Western Siberia, Central Asia, Moscow, Kyiv, Voronezh.
- Triloba or Louiseania triloba, native to North Korea and China, is most often grown as an ornamental tree. This species tolerates moderately frosty winters quite well without sudden temperature changes. It can be grown under cover even in the North-West.
Photo of blooming three-lobed almond variety Rosemund
What does almond look like?
The Almond subgenus includes low deciduous trees up to 10 m high and shrubs no more than 6 m tall. The crop is distinguished by abundant attractive flowering, as well as a fleshy mesocarp, which often dries out after the kernel ripens.
The Common Almond has the greatest economic importance, producing edible fruits and participating in the creation of decorative varieties. A botanical description of a plant does not exactly replicate all the features of other species, but will give an idea of the culture as a whole.
What does an almond tree look like?
The Common Almond forms a tree 5-6 m high. In favorable conditions, it can reach 10 m. Individual specimens, for example, a two-hundred-year-old (usually trees live no more than 130 years) almond from the Crimean Cape Ai-Todor has grown to 15 m.
The bark of an adult tree on the trunk and old branches is gray-brown, covered with vertical cracks, young trunks are dark gray and smooth. The annual growth is greenish-gray, with a reddish hue on the sunny side.Many young branches extend from the trunk at right angles, making the tree appear denser than it actually is. Depending on external conditions, the shape of the crown can be spreading, pyramidal and even weeping.
Vegetative (leaf-producing) buds have a sharp tip, generative (fruit) buds are rounded and covered with fluff. First, in March-April, pink flowers open, only then elongated lanceolate green leaves with a silvery bloom appear.
The root system of the almond tree is powerful, but poorly branched. The culture forms several strong shoots penetrating several meters deep (under natural conditions - up to 4-5 m) and is practically devoid of fibrous formations. This root structure allows the tree to survive in arid mountainous areas.
What do almond fruits look like?
Almond fruits are not nuts at all, but drupes with a maximum length of 6 cm. The weight of the kernel can reach 5 g, but in most varieties it does not exceed 3 g. Green almonds are covered with an inedible velvety pericarp, which dries out after the seed ripens, about 3 cm in size, wrinkles and cracks . In this case, the fruit often separates from the peel and falls to the ground.
The almond seed has a characteristic shape - oblong, asymmetrical, with a pointed tip, with a deep depressed stripe along one edge. It can be more or less elongated, rounded, flattened or almost cylindrical. The shell of the stone is from yellowish-gray to dark brown, dense, rough, lumpy, mottled with deep pits and grooves.
The kernel is covered with a wrinkled skin of brown shades. At the break it has a white color with a cream tint. The shape of the kernel follows the contours of the shell. Almond seeds are divided into four groups:
- papershell – nuts can be easily crushed with your fingers;
- soft-shelled – the core is easy to remove using forceps;
- hard-shelled – nuts are crushed with tongs if you apply force;
- hard-shelled – the core can only be removed with a hammer.
It is almost impossible to visually distinguish the seeds or trees of sweet and bitter almond varieties from each other. But usually (though not always) the shell of the latter is hard, and the kernel has a strong characteristic odor. But the taste of bitter and sweet almonds is easy to distinguish.
Most often, fruiting begins in the 3-4th season after planting, reaches a maximum at 20-30 years, and sharply decreases after 50-65 years. An adult tree can produce 6-12 kg of peeled kernels per season. The seeds are collected, depending on the ripening period, from July to September.
How almond blossoms
Blooming almond branches have been sung by generations of Eastern poets; Van Gogh immortalized them on his canvas. Indeed, the many opening buds surrounding a tree in a pink or white cloud at the beginning of spring look magical.
They appear in March or April, rarely - towards the end of February, before the leaves bloom. Large flowers, in the Common Almond, are soft pink, with five petals, symmetrical, single, up to 2.5 cm in diameter. The calyx is bell-shaped, stamens - from 15 to 30, one pistil.
The flowering of species almonds is very beautiful, but decorative varieties and hybrids are much more impressive.Residents of regions with warm and temperate climates rarely see fruit-bearing trees - they need real heat and a warm spring, without recurrent frosts. But there are many ornamental varieties with double or simple flowers that are frost-resistant enough to grow in the Leningrad region, Primorsky Krai and Western Siberia.
How does an almond grow?
The photo of almond bushes growing in natural conditions shows that they are located one at a time or in small groups. The culture never forms thickets. This is due to the fact that almonds have high light requirements and do not like dense plantings.
A bird's eye view of a California plantation allows one to see that the trees are growing freely, with a significant gap left between their crowns. This is the only way to get a significant harvest.
But almond trees have low requirements for soil. This doesn't mean they will grow anywhere. Almonds prefer light clays or loams, but will also take root on carbonate or leached chernozems. Trees do well on rocky slopes, sheltered from the north wind.
The crop can easily withstand drought, but may not tolerate heavy rains or watering. The almond tree can survive frosts down to -25°C, but a drop in temperature during or after flowering will cause the ovary to drop.
Interestingly, seedlings and young trees are in no hurry to shed their leaves. They fall off after the New Year or the temperature drops to -8° C. But fruit-bearing trees may be left without leaves, but with nuts, already in August.What is noteworthy is that green almonds do not fall off - the crop has enough chlorophyll contained in the pericarp for ripening and further vegetation.
Conclusion
Almonds, which produce edible kernels, grow in hot, dry climates with predictably warm springs. But through the efforts of breeders, new varieties are being created; it is possible that soon it will be possible to get a harvest in the Middle Zone. Ornamental almonds, obtained from frost-resistant species, bloom and decorate gardens even in the Leningrad region and Western Siberia.
