Strong tobacco (Nicotiana rustica, russian “makhorka”) is an alkaloid plant and industrial crop.
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Economic importance
Strong tobacco is grown for smoking (shag) grits, snuff and chewing tobacco. For smoking purposes, shag is used much less frequently than tobacco .
Dried shag leaves contain 5-15% nicotine, 15-20% organic acids, including 7-14% citric and 3-4% malic acids. The stems of shag plants contain less of these substances.
The raw materials of shag are used in the pharmaceutical industry for the production of nicotinic acid (vitamin PP), the food industry for the production of citric acid and the textile industry.
Shag seeds contain 35-40% fatty oil, which is used in the manufacture of paints, varnishes and soaps.
Strong tobacco can serve as a raw material for the production of environmentally friendly insecticides. The soil and climatic conditions of many regions of Russia make it possible to significantly expand the sown areas of this crop.
Crop history
North America is considered the birthplace of shag.
Cultivation areas and yield
The cultivated area occupied by shag is much less than the cultivated area of tobacco. It is cultivated in India, Algeria, Tunisia, Poland.
Strong tobacco is cultivated in the Central Black Earth zone of Russia, in Mordovia, Chuvashia, Tatarstan and Western Siberia, as well as in Ukraine.
In the USSR, the sown area of shag was 10,000 hectares in the USSR.
Botanical description
Strong tobacco or makhorka (Nicotiana rustica L.) is an annual plant of the Solanaceae family. Not known in the wild. It is an interspecific hybrid from the natural cross-pollination of two wild species (Nicotiana undulata and Nicotiana paniculata).
Taproot, highly developed.
The stem is erect, ribbed, with a loose core. Plant height reaches 1.2-1.5 m.
The leaves are petiolate, fleshy, heart-shaped or ovate with a wrinkled surface, dark green, light green or yellow-green. The number of leaves per stem is a varietal characteristic and is usually 12-20.
In the axils of the leaves, lateral shoots are formed – stepchildren.
The stems and leaves are covered with short capitate hairs with a strong specific smell.
Inflorescence – panicle. The flowers are bisexual, green or yellowish-green, quintuple type, with bracts. Plants are self-pollinating, but cross-pollination is also noted.
The fruit is a bivalve (two-celled) multi-seeded box. In one box 200-600 seeds are formed. Seeds are small, brown or cream. Weight of 1000 seeds 0.25-0.35 g.
Biological features
Strong tobacco is less demanding on heat than tobacco. Germination of shag seeds begins at a soil temperature of 7-8 °C. The optimum temperature for growth and development is 20-25 °C.
Shag is sensitive to low temperatures, plants are damaged at a temperature of -2 … -3 °C.
Strong tobacco is demanding on moisture. Optimum soil moisture is 55-70% HB. The transpiration coefficient is 450-500.
Strong tobacco is a long day plant. With the advancement of its crops to the north, it accelerates its development, which allows it to be grown even in the Arctic.
Loamy chernozems, gray forest, sandy and loamy sod-podzolic soils are considered optimal for shag.
Vegetation
There are two periods in tobacco culture:
- growing seedlings from seeds in greenhouses or soil ridges;
- growing tobacco from seedlings in the field.
The seedling formation period usually lasts 45-50 days, but depends on the variety and usually ends by the time 5-6 true leaves appear.
The period from planting seedlings in the field to the onset of technical ripeness of the leaves of the upper tier lasts 80-120 days. Rooting of seedlings after its transplantation in the field is 10-15 days, after which the phases of stemming, budding, flowering, seed formation and maturation begin.
The formation of leaves in tobacco occurs in tiers.
Technological properties of leaves are determined by varietal characteristics, layering, growing conditions.
Crop rotation
The best predecessors of strong tobacco in the crop rotation are winter cereals, corn, root crops, legumes, annual and perennial grasses, vegetables.
Bad predecessors are gourds, potatoes (all solanaceous), hemp, sunflower, as they have common diseases and pests with it.
Strong tobacco serves as a good forerunner for many field crops.
Strong tobacco allows repeated crops.
Strong tobacco crop rotation
Among the strong tobacco crop rotations are used:
- grass-rowed:
- 1-2 – perennial grasses, 3-4 – strong tobacco, 5 – leguminous, 6 – strong tobacco, 7 – annual grasses with overseeding of perennial grasses – 42.7% strong tobacco;
- 1 – clover , 2-3 – strong tobacco, 4 – corn for silage, 5 – strong tobacco, 6 – annual grasses with overseeding of perennial grasses – 50% strong tobacco;
- tilled:
- 1 – corn for silage, 2-3 – strong tobacco, 4 – grain legumes, 5 – strong tobacco – 60% strong tobacco;
- 1 – annual herbs, 2 – strong tobacco, 3 – root crops, 4 – strong tobacco – 50% strong tobacco.
Fertilizer system
Strong tobacco consumes relatively few nutrients from the soil. For the formation of 100 kg of dry leaves and stems, it consumes 2.4 kg of nitrogen, 1 kg of phosphorus, 3.5 kg of potassium.
Strong tobacco responds well to the application of organic and mineral fertilizers. The application rate of manure depends on the fertility of the soil and is usually 40-60 t/ha. When combined with mineral fertilizers, the rate of manure is reduced.
The recommended application rates of mineral fertilizers to obtain a yield of dry leaves and stems of 3.0 t/ha on various soils are:
- on sod-podzolic – 120 kg/ha of nitrogen 120, 60 kg/ha of phosphorus, 90 kg/ha of potassium;
- on leached chernozems – 90 kg/ha of nitrogen, 60 kg/ha of phosphorus, 60 kg/ha of potassium;
- on peatlands – 20 kg/ha of nitrogen, 90 kg/ha of phosphorus, 120 kg/ha of potassium.
Manure and 2/3 of the entire norm of phosphorus and potash fertilizers are applied in autumn under deep plowing. In the spring, for cultivation, when sowing or planting seedlings and for top dressing, all nitrogen fertilizers and the rest of phosphorus and potash are applied.
Before sowing shag, a mixture is prepared in the field, consisting of superphosphate, at the rate of 20-30 kg of phosphorus, and 5-10 times the amount of humus. Seeds are poured into the mixture and mixed well, after which they are sown.
When planting seedlings, superphosphate (20 kg of phosphorus) and nitrogen fertilizers (15-20 kg of nitrogen) are applied simultaneously with irrigation water. The remaining amount of mineral fertilizers is used as top dressing.
Tillage system
Autumn tillage for strong tobacco includes:
- two peelings (after grain crops) with disc tools to a depth of 6-8 cm and 10-12 cm;
- early deep plowing by 25-30 cm (Vavilov; according to other recommendations 20-22 cm, Kolomeichenko).
In the spring, plowing is harrowed and 1-2 cultivations are carried out, followed by harrowing and leveling the soil surface.
Growing methods
Strong tobacco can be grown in two ways: seedlings (seedlings) and sowing seeds in the field (seeding).
The seedling method is important for the northern regions of cultivation. This method is associated with an increase in the cost of growing seedlings and planting them. However, low-lying areas flooded with hollow water and insufficiently structured soils can be occupied under it.
Elevated areas with light structural soils are best suited for seedlings.
Growing seedlings (saplings)
Strong tobacco seedlings are grown in greenhouses or on soil ridges.
The seeding rate in greenhouses is 1.5-2 g/m2, on warm beds – 2-2.5 g/m2, on cold beds – 2.5-3 g/m2.
Before sowing, the seeds are subjected to dressing in a weak solution of formalin and germinated at a temperature of 25-28 °C for 3-4 days. Before sowing, the seeds are mixed with clean sand in a ratio of 1:40.
For planting 1 hectare of shag, depending on the varietal characteristics, there are 30-45 m2 of greenhouses or 45-60 m2 of warm ridges.
Seedling care
Seedling care involves maintaining the optimum temperature (18-20 °C), thinning plants, 2-3 feedings, watering and hardening.
Seedlings ready for planting should have 5-6 true leaves and a height of 8-12 cm. Growing seedlings in greenhouses usually takes 30-35 days, in ridges – 40-45 days.
Transplanting
Planting seedlings of strong tobacco is recommended to be carried out in the early stages, after spring frosts, when the topsoil warms up to 10 °C. For the south of Ukraine, landing begins in late April – early May, in the Central Black Earth zone of Russia – in the second decade of May, in the north of the Non-Chernozem zone and in Siberia – in the third decade of May – early June.
Planting of seedlings is carried out manually or with the help of transplanters with a row spacing of 50-60 cm and a distance between plants of 20-30 cm.
For large-leaved varieties of shag, the plant density is recommended to be 60-70 thousand/ha, medium-leaved – 70-80 thousand/ha, small-leaved – 80-90 thousand/ha.
A square-nest method of placing plants according to the 50 × 50 cm scheme can be used, while two plants are planted in a nest.
Sowing (seedling)
They start sowing strong tobacco at an early date, simultaneously with the sowing of early grain crops.
For sowing, a mixture of germinated and dry seeds is used in equal amounts. Germinated seeds germinate 6-7 days after sowing, dry seeds – after 15-18 days. This approach allows you to get good seedlings if early shoots from germinated seeds have suffered from frost.
The method of sowing shag is wide-row with row spacing of 50-60 cm. For sowing, special or grain seeders with depth limiters can be used. The seeding rate is 2-3 kg/ha. Seeding depth no more than 1 cm.
Landing care
Before the emergence of seedlings during the formation of the soil crust, its destruction is carried out with the help of rotary hoes.
The first loosening of row spacing is done at the beginning of emergence to a depth of 5-6 cm. The second loosening is carried out 8-10 days after the first to a depth of 6-8 cm.
Bouquet of crops begins in the phase of two true leaves. With a wide-row sowing method with row spacing of 60 cm, the width of the cutout is 20 cm, and the length of the bouquet is 10 cm, the distance between the centers of the bouquets should be 30 cm. After 2-3 days, the bouquets are thinned, leaving 3-5 well-developed plants in them.
The final breakthrough is done 10-12 days after bouquet, when the plants have 5-6 leaves. With a wide-row sowing method, one plant is left in each bouquet, with a square-nested method – two of the best. Simultaneously with thinning, the first top dressing is carried out.
The recommended planting density of shag seedlings is the same as seedlings: 60-70 thousand plants per ha for large-leaved varieties, 80-90 thousand/ha for small-leaved varieties.
After thinning, 2-3 loosening of row spacings and top dressing are performed.
Before the first or second inter-row treatment, the seedlings and seedlings are cleaned, that is, the removal of 2-3 lower leaves.
During budding, topping is done, that is, the removal of inflorescences, and when lateral shoots grow by 5-7 cm, pinching.
Harvesting and drying
Harvesting of shag is carried out in one step with whole plants at the onset of technical ripeness, which is characterized by brittle leaves and their sagging. At the same time, mature leaves emit a strong peculiar smell. Delay in harvesting shag can lead to damage to plants by autumn frosts.
To speed up the drying of ripe shag, its stems are cut from top to bottom (plastered) 3-4 days before harvesting, leaving the lower part of the stem 5-6 cm long intact so that the plants do not die. The layering method allows to reduce drying by 10-12 days and reduce the loss of dry matter.
The shag is harvested by hand in dry, sunny weather. For this, the plants are cut down at the root, leaving not even small stumps. Cut down plants are left in the field for drying. Drying is completed when the leaves become soft and will not break when bent.
From the field, shag is transported to drying rooms, where it is subjected to languishing at a temperature of 30-40 ºС for 20-24 hours. The width of the stack is made equal to the length of two plants, the height is 50-70 cm. After languishing, the shag is dried for 25-30 days in well-ventilated rooms. Drying is considered complete when a moisture content of 35% is reached.
Sources
Crop production / P.P. Vavilov, V.V. Gritsenko, V.S. Kuznetsov and others; Ed. P.P. Vavilov. – 5th ed., revised. and additional – M.: Agropromizdat, 1986. – 512 p.: ill. – (Textbook and textbooks for higher educational institutions).
V.V. Kolomeichenko. Crop production / Textbook. — M.: Agrobusinesscenter, 2007. — 600 p. ISBN 978-5-902792-11-6.