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As soon as the word “almond” sounds, some represent tasty nuts of a characteristic shape, others – a small tree covered with a cloud of pale pink flowers. Children know Raffaello sweets, and adults know Amaretto liqueur, an indispensable ingredient of which is a fragrant kernel of a stone, 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 culture is gradually mastering cool regions.
Is almond an apricot pit or not?
Some believe that apricot kernels are almonds. This is a delusion, and a dangerous one. Apricot kernels, like almonds, contain amygdalin, which releases hydrocyanic acid when split. True, the concentration of poison in the core is low, and during heat treatment it is significantly reduced, but it can still harm the body, especially for children.
Apricots are grown for their juicy fruits, the pits are supposed to be discarded before use. Therefore, breeding is aimed at breeding varieties with various pulp characteristics, and no one is engaged in reducing the concentration of cyanide compounds in the kernel. It is enough that they do not turn into fruits.
Almonds, like a fruit tree, are planted exclusively to obtain kernels of seeds, erroneously called nuts. Over the millennia of selection, the concentration of amygdalin in them has been reduced to a minimum.
It is impossible to confuse apricot and almond pit. In the latter, it looks like a peach, although usually smaller in size, and is covered with deeply depressed dots, strokes. If we compare the seeds of apricot and almonds 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 his cultivated trees that give bones, the kernels of which are eaten. They are called almonds, and although this, from a botanical point of view, is incorrect, the name has taken root.
Species trees produce seeds with bitter kernels containing a large amount 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 seeds of a species plant are commonly called bitter almonds (Prunus dulcis var. Amara). Sometimes they are considered inedible, but this is not so. Bitter almond kernels can be eaten, although in small quantities. It is believed that the lethal dose for children is 5-10 “nuts”, for adults – 50. But, given that even sweet almonds are recommended to eat no more than 10 kernels a 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 for 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 bones, 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 does almond grow
The common almond has been cultivated for so long, and the crop itself has proved so attractive for cultivation in hot, arid climates, that scientists can only speculate where it comes from. Most botanists agree that the primary focus of the appearance of the species falls on Western Asia. The almond tree is mentioned in the Bible; from later sources, the “Book of a Thousand and One Nights” should be noted, the roots of which go back to ancient times, and the origin has not yet been clarified.
Cultural plantations of trees covered the territory of Ancient Greece and Rome in the Mediterranean, Tunisia, Algeria, Morocco in Africa. In the Ferghana Valley, there is a “city of almonds” Kanibadam (Tajikistan). In addition to the Central Asian countries – Uzbekistan, Kyrgyzstan and Tajikistan, the culture is common in Armenia, Dagestan and Georgia, where the trees came from Persia, in 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 nuclei reached 1,1 million tons, and the supply to the external market – about 710 thousand tons. Spain, Iran, Italy, Morocco and Syria follow them 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. Breeding is aimed at developing trees that can withstand low temperatures, return frosts and soil moisture that is higher than usual for the crop.
Decorative trees
In addition to edible varieties, there are ornamental trees and shrubs. They also like warmth, but can grow in regions that have a much more severe climate. For use in landscape design, varieties are bred by crossing the following species with Almond Ordinary:
- Steppe, Low or Bobovnik under natural conditions grows in Southeast 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 one, species, endemic to the Caucasus. Can grow in the Moscow and Leningrad regions.
- Ledebour, whose range 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 – quite winter-hardy endemic of the western Tien Shan. Grown in Western Siberia, Central Asia, Moscow, Kyiv, Voronezh.
- Three-lobed or Louisiana three-lobed, which is 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. Under cover it can be grown even in the Northwest.
Photo of flowering almond three-lobed variety Rosemund
What does an almond look like
The Almond subgenus includes low deciduous trees up to 10 m high and shrubs no more than 6 m tall. The culture is distinguished by abundant attractive flowering, as well as a fleshy mesocarp, which often dries out after the core ripens.
The most important economic value is Almond Ordinary, which gives edible fruits and is involved in the creation of ornamental varieties. The botanical description of the plant does not exactly repeat all the features of other species, but will give an idea of the culture as a whole.
What does an almond tree look like?
Almond Ordinary forms a tree 5-6 m high. Under favorable conditions, it is able to 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, smooth. Annual growth greenish-gray, reddish on the sunny side. Many young branches come off the trunk at right angles, making the tree seem thicker than it really is. Depending on external conditions, the shape of the crown can be sprawling, pyramidal and even weeping.
Vegetative (leaf-giving) buds with a sharp tip, generative (fruit) – rounded, covered with fluff. First, in March-April, pink flowers open, only then do elongated-lanceolate green leaves with a silvery coating appear.
The root system of the almond tree is powerful, but slightly branched. The culture forms several strong processes 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 almonds 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 stone is about 3 cm in size, shrinks and cracks . In this case, the fruit often separates from the peel and falls to the ground.
The almond stone has a characteristic shape – oblong, asymmetrical, with a pointed tip, with a deep depressed strip 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, bumpy, mottled with deep pits and furrows.
The core is covered with wrinkled skin of brown shades. On a break it has a white color with a creamy tint. The shape of the kernel follows the outline of the shell. Almonds are divided into four groups:
- paper-shell – nuts are easy to crush with your fingers;
- soft-shelled – the core is easy to get with tongs;
- dense-shelled – nuts are crushed with tongs, if you make an effort;
- hard-shelled – The core can only be removed with a hammer.
Bones or trees of varieties of sweet and bitter almonds are almost impossible to visually distinguish 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 by 20-30 years, sharply decreases after 50-65 years. An adult tree can produce 6-12 kg of peeled kernels per season. The stones are harvested, depending on the ripening period, from July to September.
How almond blossoms
Blooming branches of almonds have been sung by generations of Oriental poets, and Van Gogh immortalized them on his canvas. And indeed, the many opening buds surrounding a tree in early spring with a pink or white cloud look magical.
They appear in March or April, rarely – by the end of February, before the leaves bloom. Large flowers, in Almond Ordinary – pale pink, with five petals, symmetrical, solitary, 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 a warm and temperate climate rarely see fruit-bearing trees – they need real heat and a warm spring without return frosts. But there are many ornamental varieties with double or single flowers that are hardy enough to grow in the Leningrad Region, Primorsky Territory and Western Siberia.
How does an almond grow?
In the photo of almond bushes growing in natural conditions, it can be seen that they are located one by one or in a few groups. The culture never forms thickets. This is due to the fact that almonds make high demands on illumination and do not like compact plantings.
Taken from a bird’s eye view of a California plantation, you can see that the trees grow freely, a significant gap is left between their crowns. Only in this way can a significant harvest be obtained.
But almond trees make low demands on soils. This does not mean that they will grow anywhere. Almonds prefer light clays or loams, but will also take root on carbonate or leached chernozems. Trees feel good on rocky slopes, sheltered from the north wind.
The culture easily withstands drought, but it may not endure heavy rains or watering. The almond tree can survive frosts down to -25°C, but a decrease 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 crumble after the New Year or the temperature drops to -8 ° C. But fruit-bearing trees in August may be left without leaves, but with nuts. Remarkably, green almonds do not crumble at the same time – the culture is enough for ripening and further vegetation of the chlorophyll contained in the pericarp.
Conclusion
The almonds produce edible kernels in a hot, dry climate with a predictable warm spring. But the efforts of breeders create new varieties, it is possible that soon it will be possible to get a crop in the Middle lane. Decorative almonds, obtained from frost-resistant species, bloom and decorate gardens even in the Leningrad Region and Western Siberia.