Tobacco is grown for its aromatic leaves, which after harvesting are dried, sorted and put through a fermentation process, after which they become the base from which cigars and cigarettes are made. The cultivation of tobacco is special in that it easily adapts to the soil and climate, so it changes its morphological properties according to these conditions.
The tobacco plant has a spindle-shaped and developed root that has good suction power and can penetrate the soil to a depth of 1-2 meters and up to 80 cm in width. The tobacco stem can grow up to 3 meters, is upright and covered with fine hairs. One stem can develop 20 – 100 leaves. The leaves are egg-shaped and are also covered with hairs that contain resins and essential oils that are essential for the quality of tobacco. Tobacco flowers appear singly or in groups, so that they form a cluster of flowers, and they can be white, yellow or pink in color. The tobacco fruit is a round or oval quiver of brown color, which contains up to several thousand seeds.
Types of tobacco
There are about a hundred different types of tobacco, and according to their quality we can classify them into three groups:
- Weaker tobacco – contains less than 1% nicotine.
- Medium strength tobacco – contains 1 – 2% nicotine.
- Strong tobacco – contains more than 2% nicotine.
Considering the quality and color of the dry leaf, we distinguish the following types of tobacco:
- Dark – more used for chewing and in pipes and cigars.
- Bright – mainly used in cigarettes.
According to the method of leaf drying, tobacco is divided into:
- Air cured – tobacco that has been dried in the air. Drying is done in large open drying rooms with natural air flow. This drying process lasts 4-8 weeks and it achieves a low level of sugar in the leaves. Air cured tobacco is further divided into dark, cigar and light types. The most famous bright types are Maryland and Burley, which, along with the Virginia type, are the most widely grown in our area.
- Fired cured – tobacco dried over an open fire. Leaves dried in this way take on the smell of the wood on which they are dried and turn dark. They have a strong smell and a good texture. They are used to make chewing tobacco and added to pipe mixes. Because they have a high proportion of nicotine and nitrogen, they are extremely strong when smoked.
- Flue cured – tobacco that has been dried in hot air in drying rooms. This method of drying achieves a uniform golden yellow color, and this tobacco is mainly used as one of the ingredients in cigarette blends.
- Sun cured – tobacco dried in the sun. It is produced in areas where long sunny periods prevail. Dry, light yellow leaves with a high concentration of sugar and a low level of nitrogen and nicotine are obtained. This type of tobacco is divided into Virginiasun cured tobacco and oriental and semi-oriental types.
According to the chemical reaction of the smoke, we distinguish:
- Alkaline tobaccos – contain more proteins, nitrogenous substances and nicotine.
- Sour tobaccos – contain more carbohydrates.
When it comes to aroma, we distinguish between aromatic and non-aromatic tobaccos. Aromatic tobaccos are oriental tobaccos that, due to essential oils and other aromatic substances, have fragrant leaves after drying, and release a special aroma when smoked.
Many enjoy tobacco because of the chemical composition of its leaves, which affects the central nervous system. When it comes to the chemical composition of tobacco, the most important is nicotine, it can have a calming or irritating effect on the human body, depending on the state of the nervous system. Of the other ingredients that attract and encourage people to enjoy tobacco, resins and essential oils stand out.
High-quality tobacco should not contain more than 8% protein because it has a bitter taste, burns less, has an unpleasant smell and stimulates coughing. When tobacco is processed from leaves and waste, nicotine is obtained in its pure form, and as such it is used in the pharmaceutical industry and as an insecticide for plant protection and in the household.
Planting tobacco
Due to the lack of suitable land for growing tobacco, it is mainly grown in monoculture, which leads to soil depletion and the appearance of a greater number of pests and various diseases. Tobacco must be grown in crop rotation, because only in this case can a high and high-quality nature be achieved. It can be planted in the same place every four years.
Good starters for tobacco are legumes and small grains, and after removing tobacco from the plot, it would be best to sow fodder peas with cereals, rye or vetch, and plow the green mass to improve soil properties.
Light, structural, loose and airy soils on hilly or other inclined positions are best for growing tobacco. The soil should be slightly acidic to neutral. If small grains or other early pre-crops were grown on the land where tobacco will be planted, it is necessary to plow shallowly, 10 cm deep. Summer plowing should be done at the beginning of August, and deep plowing at a depth of 30 – 35 cm in autumn. It is also necessary to do undermining, then towards the end of winter, harrowing, and till the sowing of tobacco, cultivation. Immediately before planting, the soil is prepared with a seeder and 30 cm high beds are formed.
If you plan to plant tobacco on poor and lighter sandy soils, manure must be added to them during the basic soil treatment. Mineral NPK fertilizers should also be added to the soil in the ratio 5:20:30 and 7:14:21 (500 – 1000 kilograms per hectare). It is recommended to use fertilizers that have more nitrogen in ammonium form, so 30 – 70 kg of nitrogen, 100 – 200 kg of potassium and 70 – 140 kg of phosphorus are needed per one hectare.
On smaller areas, tobacco is planted in rows between which a distance of 75 cm should be left, while the distance between plants in a row should be 30 – 40 cm. In plantation cultivation, a distance of 100 cm is left between the rows, and the distance between the plants within the rows should be 35 cm. Tobacco is planted by hand, in holes 10 cm deep, or with four-row planters at a depth of 8 – 16 cm.
Cultivation of tobacco and maintenance of plantations
The minimum temperature required for the germination of tobacco seeds is 5°C, but the seeds will germinate much faster at a temperature of 12°C. Plants do not tolerate low temperatures, so they will suffer if the temperature drops to -1°C.
We distinguish long-day tobacco cultivars, short-day cultivars and neutral cultivars. In any case, tobacco needs a lot of light, so it should not be planted in shaded areas, allowed to take over the plantation or grown in too dense a structure. More light means better photosynthetic activity and accumulation of carbohydrates, and therefore more nature and better quality of the leaves.
When it comes to water, tobacco has the greatest needs during seed germination and during the growth phase. After the tobacco is planted in a permanent place, it is important to water the plantation regularly so that quality roots can develop. If there is a drought during the time of intensive vegetative growth of plants, it is necessary to carry out irrigation. Later, as the tobacco matures, its water needs decrease.
Tobacco plantations should be protected from weeds, and they can be controlled mechanically or chemically. If you want to avoid the use of chemical agents, regularly cultivate, hoe and weed the plantations. Cultivation is done after the rain, but when the soil has dried enough. The first cultivation should be done 7 – 14 days after planting, and the next when the plants reach a height of 30 cm.
It is also necessary to cut off the flowers and leaves because they consume nutrients that should go to the leaves. Cleaning the petals and plucking the flowers is done when 60% of the plants are in the budding phase. It is important to do this on time because every delay reduces the yield by 1% per day.
Hydroponic tobacco cultivation
Given that growing tobacco in beds has not proven to be good enough, today tobacco seedlings are most often grown hydroponically – in polystyrene containers in greenhouses, on the surface of the nutrient solution. For the production of seedlings in this way, tunnel-shaped greenhouses 15 – 45 m long and at least 4.5 m wide are needed. The greenhouses should be covered with polyethylene film 0.22 mm thick and erected in places where maximum sunlight and heat can be used. The air temperature in the greenhouse during the day should range from 22 – 24°C, and at night it should not be lower than 15°C.
Before sowing, you should add NPK fertilizer in the ratio 20:10:20, and after the plants develop four leaves, they should be fed with nitrogen.
Peeled tobacco seeds are sown in polystyrene tiles of size 303 x 515 mm. The tiles are mechanically filled with a mixture of black and white peat. The machine uniformly fills the trays and compacts the substrate as much as necessary, and in the seed boxes it makes depressions, into which it adds one peeled tobacco seed.
For the production of tobacco seedlings in this way, sowing is done 50 – 60 days before transplanting into the field, that is, in the first half of March. After sowing, the plates are placed on the nutrient solution in the greenhouses. The nutrient solution is obtained by mixing water and water-soluble mineral fertilizer.
Fungicides, Kidan and Previcur, are added to the nutrient solution as a preventive measure, each in an amount of 10 ppm. The mentioned preparations will protect young tobacco plants from potential diseases. In the sprouting and rooting phase of the plants, it is necessary to add water to the nutrient solution and at the same time add the same protective agents (5 ppm of each of them). In the event that a disease appears, the same amount of the mentioned means can be added again.
Diseases and pests
Diseases that can threaten tobacco cultivation are tobacco blight and tobacco mosaic virus.
Tobacco burner
Blight can appear at any stage of plant development, and it is caused by the pseudofungus Peronospora tabacina, which attacks only the aerial parts of tobacco. Round-shaped chlorotic spots appear on the face of the leaves of infected plants, and a blue-gray velvet coating is formed on the reverse side.
The fire blight is controlled with preparations based on active substances (benalkyl and mancozeb in the amount of about 3 kg/ha and metalaxyl and mancozeb in the amount of 2.5 kg/ha).
Tobacco mosaic virus
Symptoms that may point to this disease are the yellowing of leaves and veins, the appearance of light and dark zones on the leaves, and the slow growth of tobacco. Since there are several strains of the virus, it is difficult to determine the exact virus without using the appropriate molecular and serological techniques in the laboratory.
Pests can include thrips and aphids. They are carriers of viral diseases, so viruses can be prevented by timely control of these pests.
Apart from them, corn moth caterpillars, wireworms and ground owls can also appear.
Tobacco harvest
Tobacco leaves gradually ripen from the bottom to the top of the stem and are harvested in a technical harvest. Harvesting usually starts 55 – 60 days after planting and is done by hand or machines. 2 – 3 leaves ripen per week, and harvesting usually starts at the beginning of July and lasts until mid-October.
Tobacco leaves are ready for harvesting when they stand at a right angle to the stem, the leaves take on a bright yellow-green color and break slightly when trying to harvest. If the land is flat and the plants ripen evenly and are of uniform height, harvesting can also be done with a combine harvester.
Processing, storage and purchase of tobacco
After harvesting, the tobacco leaves are placed in baskets and then taken to stringing. They are placed on a two-meter-long thread, which is then placed in a closed and dark room until it turns yellow. After that, it should be further dried in the sun. When dried, the tobacco is prepared for purchase. The leaves are ready for purchase when they contain 15-16% moisture. They should not be too wet, because then they will stick, but not too dry, because then they will crumble.
The dried tobacco is taken out of the frames and transferred to separators, where dusting and sorting are then carried out. After separation, according to quality and insertions, it is placed in cardboard boxes and stored in the manufacturer’s warehouse.
The purchase of tobacco by inserts is done on the purchase line, and the position, color and size of the leaf, tissue characteristics, mechanical damage, damage from pests and diseases, and the amount of dirt and moisture are evaluated.
History of tobacco
In the countries of the Old World, tobacco was first heard of after Columbus’ voyages to America. Tobacco arrived in France for the first time thanks to Jean Nicot, the French ambassador to Portugal, who presented tobacco as a medicinal plant. Later, the most important chemical composition of tobacco – nicotine – was named after him.
In Europe, tobacco was initially grown as a medicinal plant. Tobacco leaves were placed on wounds, and tobacco juice was taken against stomach ailments. In a book on herbs from 1656, it is stated that tobacco clears the throat, protects against the plague, relieves toothache, relieves fatigue and pain, and treats inflammation, wounds and ulcers.
Around 1650, Prince Friedrich Wilhelm of Brandenburg settled the Huguenots in the devastated areas, and they began to grow tobacco as their agricultural activity. About ten years later, they started opening shops where you could get chewing tobacco. In 1688, tobacco cultivation spread from that area to other places.
Today, the largest producer of tobacco is China, and it is grown in another 120 countries around the world. Wild or rustic tobacco called Nicotiana rustica is grown in Poland and Russia. Most of the produced tobacco is used for the production of cigarettes, and the most widespread type is Virginia tobacco, to which almost all other varieties belong.
The stalks are removed from the cleaned and dried tobacco leaves, and then they are used in pipes or rolled into cigars and cigarettes. When smoking tobacco, most of the toxic nicotine is burned, while a smaller part evaporates and is taken into the body by inhalation.
Smoking cigarettes creates a nicotine addiction that is difficult to get rid of later. Smoking is associated with various diseases and health problems such as problems with the heart and blood vessels, impotence and some forms of cancer.
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