Peppermint (Mentha piperita) is an essential oil and medicinal crop.
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Economic importance
Mint is grown to produce leaves that contain (1.5) 2.0-3.5% essential oil. Peppermint essential oil is used in medicine, perfumery and confectionery.
Essential oil promotes the expansion of blood vessels of the heart, lungs and brain, is used as a wound healing, choleretic, analgesic and sedative. A mixture of menthol and oil has anti-inflammatory properties and is used for colds.
The main component of the essential oil is menthol, the content of which reaches 50-70%.
Cultivation areas and yield
Peppermint was introduced into cultivation about 250-300 years ago.
In Russia, mint was brought from England and began to be cultivated in the 19th century.
It is grown as a cultivated plant in small areas in Western Europe, Asia (China, Korea, Japan) and the USA.
The main crop areas on the territory of the former USSR are located in the Krasnodar Territory and North Ossetia of Russia, the forest-steppe part of Ukraine, Moldova, Belarus and the Baltic countries.
In 1984, the sown area in the USSR was about 9 thousand hectares.
The yield of dried peppermint leaves reaches 0.8-1.0 t/ha (Vavilov). According to other data, the average yield is 1.5-2.0 t/ha, in favorable conditions it reaches 3.5 t/ha.
Botanical description
Peppermint (Mentha piperita L.) is a perennial rhizomatous plant belonging to the Lamiaceae (Labiatae) family.
The rhizome lies in the soil at a depth of 5-6 cm.
Stems erect, branched.
Plant height 50-80 cm.
The leaves are opposite, small, oval-lanceolate, serrated along the edges. On the underside of the plastic sheet, along the veins, there are numerous glands in which essential oil is formed.
The flowers are mostly female, small, pinkish, collected in groups in loose spike-shaped inflorescences. Flowering occurs profusely, but seeds are almost not formed.
Biological features
Peppermint is undemanding to heat.
Able to overwinter well with little snow cover without shelter.
The buds on the rhizomes begin to grow at a soil temperature of 2-3 °C. Young shoots of mint are able to tolerate frosts down to -6 °C. It does not tolerate sharp fluctuations in temperature from the end of winter to early spring, which is associated with the beginning of the germination of rhizomes.
Moisture-loving plant. The optimal soil moisture, at which the above-ground mass develops most intensively, is 80% of the lowest soil moisture capacity. Does not tolerate prolonged drought.
Peppermint is demanding on light: when shaded, the oil content in the leaves decreases.
The best soils are low-lying fertile sandy loamy or light loamy chernozems and drained cultivated peatlands. It grows poorly on heavy, alkaline, sandy and acidic marsh soils.
Vegetation and reproduction
Reproduction is vegetative by means of rhizomes and shoots.
Seedlings are harvested from young shoots, which are formed from overwintered lashes and rhizomes in spring. For these purposes, segments of rhizomes with 3-4 knots are better suited than parts of lashes. Planting material harvested in autumn is usually stored in special piles. The pile is a dug trench 1 m wide and 50-60 cm deep. The rhizomes in the pile are laid in layers of 5 cm and sprinkled with soil. From above they fall asleep with a layer of soil 20-30 cm thick. The optimum storage temperature in piles and storages is +1 … +3 °С.
Sometimes the rhizomes are not dug up, and the field of mother plants of mint is covered with straw manure or other insulating materials.
Crop rotation
In the crop rotation, fertilized tilled crops (potatoes, sugar beet), as well as winter crops, going along fertilized fallows and along the turnover of the layer of perennial grasses, are considered the best predecessors of mint.
With good care, peppermint can be grown in one place for 2-3 years.
Fertilizer system
Peppermint is responsive to organic and mineral fertilizers.
The recommended application rate for manure is 15-20 t/ha (Vavilov; according to other recommendations, 30-50 t/ha of manure or compost, Kolomeichenko), directly under mint.
Recommended application rates for mineral fertilizers N90P60K90. (Vavilov; according to other recommendations, when combined with organic fertilizers – N45P45K45, in the absence of organic fertilizers – N60-90P60-90K60-90, Kolomeichenko).
Manure and part of the mineral fertilizers are applied as the main fertilizer in the fall, the rest of the mineral fertilizers are applied before cultivation, when planting rhizomes and as top dressing.
Peppermint responds well to ammonium nitrate, ash and bird droppings.
Recommended fertilizer application rates for feeding seedlings: 100 kg of ammonium sulfate, 150 kg of superphosphate, 50 kg of potassium salt or 5 tons of diluted slurry, 200-300 kg of chicken manure per 1 ha. The first top dressing is carried out immediately after the start of the seedling vegetation, the second – after 20-25 days.
After harvesting the leaves, mineral fertilizers are applied in the amount of N90P120K90 with embedding them with harrows.
Tillage system
An important agricultural technique is considered to be snow retention, which is carried out with the help of rocker crops.
Planting
Peppermint is planted with rhizomes in early spring, simultaneously with the sowing of early spring crops. In the conditions of Moldova and the Krasnodar Territory with relatively mild winters and high soil moisture in autumn, planting of rhizomes can be carried out in autumn – at the end of October – the first half of November.
The best planting method is with row spacing of 70 cm. When planting, the rhizomes are laid in a continuous tape in moist soil, the grooves are immediately covered with soil.
Planting is carried out by transplanting machines adapted for planting rhizomes, or manually.
The planting rate of rhizomes is 800-1000 kg/ha (Vavilov; according to other recommendations, 500-600 kg/ha, Kolomeichenko).
Planting depth in spring (6) 7-8 cm, in autumn – 10-12 cm.
As planting material, seedlings from young shoots can be used, which are bred in the spring in a nursery from overwintered lashes and rhizomes. The shoots of seedlings are dug out of the nursery and immediately planted with watering in a wide-row way (70 cm), in a row the distance between plants should be 12-15 cm.
Planting of seedlings in the southern regions begins in April, in Ukraine – in early May, with a plant height of 8-10 cm at the rate of 8-10 plants per 1 m of row. Plant density should be at least 130 thousand/ha.
Crop care
Full shoots when planting rhizomes occur in 28-30 days.
Before germination, harrowing is carried out with light or medium harrows across the rows.
During the growing season, 2-3 (Vavilov; according to other recommendations, up to 4-5 during the summer, Kolomeichenko) processing of row spacings are carried out. The first inter-row cultivation is carried out when shoots appear, leaving protective strips 15-20 m wide. Subsequent treatments are carried out as necessary with weeding.
In plantings of the second and third years, if necessary, segments of rhizomes or rooted shoots are planted.
When leaving the plantation for the second and third years, after harvesting the second cut, to ensure good development of rhizomes, row spacing is cultivated to a depth of 6-8 cm. Autumn mulching with manure at the rate of 20-30 t/ha gives a good result.
Harvest
Peppermint leaves are harvested during the first, second and third years of life. Maximum productivity is noted in the second year of plant life.
Harvesting is started in the phase of technical ripeness. In plants of the first year of cultivation, it occurs when 50% of plants bloom (Vavilov; according to other recommendations, in the full flowering phase, Kolomeychenko) or at the end of July, the second and third years – with mass budding or at the end of June.
Mowing is carried out by hay mowers, legume mowers and bean harvesters, for example, ЖБА-3.5А.
The mowed mass is left in the field for 1-2 days, the moisture content of the mass should reach at least 30%. After drying, it is picked up with the help of pick-up loaders, collected in vehicles and sent for processing.
The developed technology for harvesting and processing mint with whole dried plants in container cubes provides for:
- mowing plants and laying them in swaths using ЖБА-3.5L, ЖБА-4.2 harvesters, Е-301 mowers;
- drying of green mass within 1-2 days;
- selection of rolls with simultaneous grinding of dried mass and loading into
- processing machines of the КУФ-1.8 type; Е-280;
- transportation of raw materials to the place of processing.
Cultivation under irrigation conditions
Peppermint is responsive to watering. Under irrigation conditions (during the Soviet period), it was grown in the Kuban, Moldova and southern Ukraine, which made it possible to obtain up to two crops of essential oil raw materials per year. The collection of essential oil reached 60-90 kg/ha compared to 20-30 kg/ha in the absence of irrigation.
Irrigation is started when the soil moisture is 70-75% of the lowest moisture capacity. Watering is carried out using a sprinkler. Irrigation rate is 450-500 m 3 /ha. Watering is stopped two weeks before harvesting the leaves.
Continuous harvesting of mint rhizomes and thinning of transitional plantations is carried out using КПМ-2 root-thinner-thinners.
Mint rhizomes are stored in above-ground ridges. Shelter of the ridges with earth is carried out with a БН-100А bead-coverer with a thickness of the shelter of 10-15 cm. When a stable cooling occurs, that is, temperatures down to -8 … -10 °C, the thickness of the shelter is increased to 15-20 cm. The optimum storage temperature of rhizomes in the ridges is 0 …-4 °С.
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.