life of modern man and of all mankind. He became one of the first crops, wine and vinegar from ancient times played a significant role in the development of trade and navigation. Many historical facts and events are associated with grapes. It is impossible to tell all about the grapes, but the mere fact that the whole science, ampelography, is involved in planting and its cultivation deserves attention and respect.
According to the works of N. I. Vavilov, the Asian region and the Middle East became the birthplace of this culture and the center for the development of viticulture. It is here that still grows the largest number of still unexplored wild species of grapes. Here, in Georgia, evidence was discovered for the existence of winemaking relating to the 6th millennium BC.
Since then, the zone of distribution of heat-loving culture has expanded significantly. And today the grapevine cannot be met unless on the Antarctic continent. In total, more than 10 million hectares of wine and table grape varieties are allocated in the world. With the development of breeding and industrial technologies, grape varieties are becoming increasingly important not only for winemaking, but also for fresh use, making juices and raisins.
Classification of grapes: types and origin
In total, in the genus Vitis, according to the existing classification, more than seven dozen species are divided into three groups:
- is Euro-Asian;
- East Asian;
- North American.
The Euro-Asian group is, in fact, a species of Vitis vinifera, the cultural subspecies of which gave the largest number of technical and table grapes existing today. According to A. Negrul, they are divided into three geographical groups:
- orientalis– eastern;
- occidentalis - Western European;
- pontica– originating from the Black Sea coast.
Of the 28 species that make up the American group, three are well known and cultivated. At the same time, Vitis labrusca is not only the ancestor of most American varieties, but also the species, whose descendants, due to unpretentiousness and yield, are most widely distributed in the world. The berries of this type are easily recognizable by the peculiar taste, which is often called "lisy" or strawberry. An example of the most common natural hybrid of European and American type is the technical grape variety Isabella, whose history goes back almost two centuries.
The largest East Asian group of grapes includes 44 species, of which only one is studied and used in viticulture. This is Vitis amurensis - Amur grape.
Bushes are grown today in professional and amateur farms, giving rounded and elongated berries of all shades from almost black and purple to amber yellow and greenish.
Moreover, white grapes are also the result of selection work, but performed by nature itself. All wild grape species produce a dark berry, but as a result of a spontaneous mutation, which successfully entrenched, some plants lost the ability to produce staining fruits of anthocyanins. So there were white grapes.
However, grapes are not only a plant that gives juicy berries, but also a spectacular decorative vine. Therefore, certain species, such as Amur and girlish grapes, as well as Isabella are actively used in landscape design and gardening. There is even room grapes. This is a distant relative of the cultural representatives of the genus Vitis - tsissis, resembling its fruiting counterparts in the form of leaves and the appearance of the bush.
Modern grape varieties and selection of new varieties of
If we talk about existing grape varieties, whose berries have long been firmly established in human life, there are more than 20,000 of them in the world, and the vast majority are hybrids, in the genotype of which there is a European cultural grape, American labruska and Amur species.
Each of this species has its advantages and disadvantages, therefore, breeders are actively working to highlight the best features and get new table and technical grape varieties:
- with high winter hardiness;
- with large, sweet or seedless berries;
- with earlier maturity;
- with abundant regular yields;
- with good resistance to diseases and pests.
Back in the middle of the last century, Michurin was able to obtain resistant hybrids of winter-hardy Amur grapes and unpretentious American varieties, many of which are used and still early grape varieties, which made it possible to significantly expand the boundaries of viticulture in the Soviet Union.
More than half of the regions where grapes are grown in Russia are classified as zones with a sharply continental climate.
This means that the vine must withstand:
- harsh winters;
- frosts, inevitable in spring and autumn;
- lack of moisture in the spring and summer months;
- the early period of rain falling at the time of ripening or harvesting.
On the basis of the varieties obtained back in the Soviet years, such disease-resistant, cold-resistant grape varieties, such as Codreanca, Delight, Original, were derived, themselves becoming “parents” for several generations of high-yielding hybrids.
Terms of ripening of grapes
The most important is the problem of obtaining grape varieties for wine and dessert purposes, with a short growing season.
There is an opinion that the ability of a plant to quickly form a crop depends on many factors, the main of which is genetic predisposition. However, in different climatic and weather conditions, grapes of the same variety can produce a crop with a time difference of 1–2 weeks.
In addition, there are significant differences in the phenotype between varieties of northern and southern origin. For example, an early grape variety of northern origin not only in a short time gives a sweet berry, but also has time to prepare for winter. During the growing season his vine matures. Southern varieties with the same ripening time cannot often boast of such a property; their vine ripens after the grapes are harvested. And unripe seeds are often seen in ripe berries.
The period from the moment when the buds burst until the maturity of the berries in varieties of different maturity dates is:
- very early ripening 105–115 days;
- early maturity 115–125 days;
- average maturity 125–130 days;
- medium maturity 130–140 days;Late maturation
- 140–145 days;
- very late maturation more than 145 days.
However, there are already very early grape varieties that, under favorable growing conditions, are ready to be happy with the crop in 90–95 or even 85 days.
Frost tolerance of grapes
But even when growing varieties with short growing periods, it is impossible to get any significant yield if the plants do not have the required winter hardiness and are not able to survive during the seasonal frosts and winter cold. Cold-resistant grape varieties are indispensable in Russian conditions with a continental climate, where, along with the hot summer and in the southern regions, winters are quite severe.
According to the accepted classification, varieties are divided into four groups:
- weakly resistant, wintering at temperatures from –15 to –17 ° C;
- moderately stable, carrying cold from –18 to –22 ° C;
- with increased resistance, surviving at frosts from –23 to –27 ° C;
- is very resistant to frost and can withstand temperatures from –28 to –35 ° C.
Interestingly, during the year, the ability of grapes to resist cold can vary.
During the period of intensive growth, a sudden cooling down to –3 ° C can completely destroy the bushes of even frost-resistant grape varieties, which practically lose this property during summer time. Shoots at this time are filled with juices, lignification is insignificant, and the plant has no protective substances and reserves. By autumn, winter hardiness increases and reaches a maximum by January. At the same time, perennial wood is more protected than shoots. And the place of accretion of a scion and a stock differs in the greatest sensitivity.
When growing non-grape varieties, it is necessary to take into account that the buds on the bush have different degrees of protection from cold:
- Dormant buds are more secure.
- In the second place are the replacement, lateral buds.
- Central kidneys are most often affected by frost and winter cold.
The frost tolerance of grape varieties depends not only on meteorological conditions, but also on the location of the vine at a particular site, its age, readiness for winter, damage by diseases and pests.
The most active breeding work is in the direction of obtaining new varieties, the berries are consumed fresh. It is table grapes that today hold the first place in popularity among amateur gardeners and professional growers.
It is easy to select from the total mass of table grapes for a number of characteristics:
- in the size and attractive shape of large brushes;
- beautiful color, shape and size of the berries;
- pronounced aroma and taste of ripe fruit.
When breeding such varieties, much attention is paid to reducing the acidity of the berries, yields and obtaining large fruits and filled brushes. A number of agrotechnical measures that are not carried out on wine grapes are also aimed at this. Among these techniques:
- artificial pollination;
- rationing brushes and inflorescences;
- thinning of berries on clusters;
- removal of leaves shading brush.
The yield and quality of table grapes also depend on the climate, topography and soil on which the vine grows.
If earlier the harvest of table grape varieties was practically not stored, today there are varieties, both for local consumption, and that can withstand transportation and very long storage.
Seedless grapes whose berries are either completely devoid of seeds, or have only their beginnings, are becoming increasingly popular. Such berries are in demand not only fresh, juices are made from grapes, especially raisins that are not containing stones are especially valued. Lack of seeds is a serious factor in attracting consumers; therefore, recently a small group is expanding rapidly, replenishing hybrids and varieties of pink, black and white grapes of different ripening and destination terms.
It is believed that seedless grapes are represented by two types:
- raisins, belonging to the eastern group of grapes;
- cinnamon, belonging to the Black Sea basin group.
Kishmish is considered one of the most popular varieties in the world. But if on the shelves of shops more often there are grapes with rather small, but extremely sweet berries, today breeders already offer boneless early grapes with large fruits of black, white and pink color.
Since technical grapes are intended for processing, its main distinguishing feature is its juice content. The amount of juice obtained from the berries of technical or wine grapes can reach 75–85%.The second important indicator is the ratio of the mass of the comb and the weight of the berries on the brush. The denser the brush and the lower the weight of the comb, the more valuable the raw material.
At the same time, the appearance of the bunch, the harmony of color and the size of the fruits are not so important. Much more attention is paid to the mechanical and chemical composition of berries, sugar content and acidity, on which the type and quality of the products will depend. Getting a decent harvest on technical grapes depends not only on the genetic and biological characteristics of the plant, but also on the growing conditions. No wonder there are vineyards, numbering in history for several centuries and famous for its great wine.
Connoisseurs are well aware that the quality of the wine and its bouquet, in addition to the geographical and climatic aspect, is influenced by the specific location of the vine. For example, the color saturation of berries in wine grape varieties directly depends on the light intensity, the direction of the rows and the geometry of the slope on which the bushes grow. Due to the unique characteristics of individual varieties, for example, a shade of taste, like Cabernet, or aroma, like the existing varieties and hybrids of Muscat, winemakers manage to get interesting, unlike other wines and drinks.
If table grape varieties are usually not tied to a particular locality, then for technical varieties, the division into native and introduced is relevant. Moreover, the local technical grape varieties are highly valued and are the raw material for the manufacture of sometimes unique brands of wines, whose production in another locality is simply impossible.