Chamomile: Cultivation Experiences in Slovakia

Chamomile has long been one of the most important medicinal plants cultivated in Slovakia. Its cultivation started in the beginning of the 1950s in the former Czechoslovak Republic. Diploid variety Bohémia with a high content of chamazulene and α-bisaboloxide A and B was sown. In 1957 the tetraploid variety Pohoelicky Velkokvety with similar characteristics, as far as efficacious compounds are concerned, was bred, but this variety was restricted because of the high degree of disintegration.

Chamomile is a plant with a wide growing range and can be grown in the Slovak Republic almost everywhere. It grows best in warmer areas protected from wind with plentiful sunshine and mean yearly precipitation ranging from 550 to 800 mm. Soils rich in nutrients and humus, heavy to mild, mold to luvisol character are the most suitable. After almost 40 years of experience, the crops reached the required level of market production; the cultivation of chamomile in beet and potato regions was proved to be the most suitable.

With regard to the initial slow growth of chamomile, it is necessary to choose the foregoing agricultural plant that leaves the land weed-free and in a good state. From this point of view root crops, peas, beans, and mustard are the most suitable; corn is also good. Clover, clover and grass mixtures, dill, coriander, and caraway are not suitable at all. It is also possible to grow chamomile in monoculture until the weed flora resistant to the herbicides permitted is formed.

The second precondition of successful chamomile cultivation is a high-quality soil preparation. In one-year chamomile cultivation, the stubble is ploughed over by medium-deep ploughing (180-220 mm) immediately after the foregoing agricultural plant harvest. Soil surface is adjusted by cold-crusher and harrow so that it was smooth enough, clod-free, and hardened. In monocultural growing, after the harvest of chamomile, it is necessary to remove the rest of the herb by a postharvest cutting machine and then a break-up and rolling follows.

Simultaneously with the medium-deep ploughing, fertilizers are applied. To produce 1 ton of drug from 1 ha the following average doses of pure nutrients are recommended in the ratio 1N:0.14P:2.05K for 1 ha: 60 kg N, 10 kg P, 142 kg K. Only one third of nitrogenous fertilizers is applied before sowing, the remaining two thirds are applied in two doses after overwintering and the second weeding.

Chamomile can be sown at any time of year on the soil surface, because the germination requires the presence of light. However, in order to reach a high crop and to be able to dry the harvested biomass, the sowing is limited to two periods.

Autumn sowing from August 15th to September 15th is recommended for the regions with regular autumn rainfall and frosts coming after October 20th. Chamomile sown in this period germinates quickly, takes roots well, and grows in the period of humid and warm-enough weather.

Spring sowing is suitable for all regions with the exception of dry and warm ones, where total rainfall for April and May does not reach 50 mm and day temperatures exceed 15°C. Spring sowing is applied to approximately 30% of production area in order to ensure continuous harvest up to August 15th. The sowing takes place from March to the end of April, and five to six harvests are reached.

The quantity of the seeds sown depends on the seed quality and varies from 1.5 to 2.5 kg / ha. In monoculture a self-seeding occurs, thus the quantity of seeds for sowing applied is lower. Chamomile is sown, dependent on the subsequent mechanization, to rows 30–45 mm apart.

From the point of view of mechanized harvest and drug quality, overriding attention should be paid to the purity and the state of health of the stand. Herbicides are effective in the struggle against weeds; however, they must be applied correctly. The most important damage to chamomile is caused by sucking insects, above all by Erophyes convolvens and representatives of Thysanoptera, Heteroptera, and Homoptera.

Cultivation areas of chamomile in Slovakia have varied from 150 to 400 ha in the last ten years, according to market demands. These demands are much influenced by the amount of chamomile collected from natural resources, which reached 30 to 50%. Up to 1990 only one firm was a monopoly bulk buyer and processor of chamomile. Export is recorded directly by producers for west European countries (Table Purchase of Chamomile by Liecivé Rastliny (Medicinal Plants) Malacky Division, Export in Tons and Prices).

Table Purchase of Chamomile by Liecivé Rastliny (Medicinal Plants) Malacky Division, Export in Tons and Prices

Year Wild Cultivated Export Price, 1st class (€)
1986 46 5 2.13
1987 46 15 2.13
1988 28 15 2.25
1989 62 14 2.25
1990 34 15 2.50
1991 20 7 14 2.75
1992 26 34 3.00
1993 34 39 3.00
1994 18 5 45 3.25
1995 19 16 27 3.50

The present need of chamomile drug is insufficient for the inland market in Slovakia. Cham-omile flower is imported by processing pharmaceutical firms. On the other hand, producers export their product directly, or by means of commercial firms to west European markets under relatively advantageous conditions. In order to intensify producers’ activities in the field of medicinal plants, the interest group Rumancek (Chamomile) was found in 1996. It is a nonprofit association of both trade and juristic persons that represents the interests of improvers, cultivators, and processors of medicinal, aromatic, and tonic plants. The objective of the association is the enlargement of area and the rise of efficiency of breeding, cultivation, and processing of medicinal, aromatic, and tonic plants both for inland market and export, which should reach 20% of domestic production. The next goal of the association is to ensure the coordination in the field of breeding, cultivation, research, and production of final products from medicinal, aromatic, and tonic plants and to reach 2500 ha of cultivation area in the Slovak Republic, including the area for chamomile up to 500 ha. The overall picture of chamomile cultivation gives us its economic evaluation. It was applied to a model firm in the Agricultural Farm Rozkvet in Nová L’ubovna village in the years 1983–1992. This agricultural firm completely exploited the chamomile biomass for drug, seeds, essential oils, and extracts. Adequate prices and state appropriation for the years 1991–1992, when there was a disproportion caused by the growth of outlays and fall of prices and a substantial reduction of appropriations, had a favorable influence on economic results. The negative influence of prices and appropriation inputs changed the orientation of the market with respect to the export of chamomile drug above. The conditions for prospective quick growth of chamomile cultivation also within the criteria of alternative cultivation are given by long-term absence of pesticides in soil, fertilizers being applied only in minimum doses, and mechanical cultivation.

Research, Breeding, Seed Growing, and Varieties

Research

State research of medicinal plants in the former Czechoslovakia was a dominant task mostly of the institutions situated in Slovakia. From the beginning of complex research, Slovakofarma Hlohovec was a co-ordinator. Ing. Ivan Varga, present director for science and research of Slovakofarma, was the responsible coordinator of these activities in the years 1980–1997.

Chamomile research started in 1976 at the Department of Experimental Botany and Genetics of the Faculty of Science of P. J Safárik University in Kosice (FS PJSU) by a partial task force on the “research of chamomile cultivation in soils with high salt content.” The goal of the research was to find the most suitable complex chamomile farming technology aimed at the obtaining the maximum crop of high-quality drug.

The research continued from 1980 to 1990 and was expanded by another research workplace: Agricultural Farm in Nová L’ubovna. It was aimed at the solution of problems of large-scale cultivation of this medicinal plant, harvest, the development of a wide-space chamomile harvester, postharvest arrangement by presorting of plant biomass, and also the sorting and stalk removing of the dry drug. It also built up a shop for scientific and technological development and piece production of machines for harvest, postharvest arrangement, and technological processing of chamomile.

Breeding and Seed Growing

Simultaneously with cultivation research, the research collectives dealt with breeding and preparing the material for registration for a variety tests.

In the course of 20 years the collective of breeders of the Department of Experimental Botany and Genetics of FS PJSU in Kosice, Agricultural Farm Rozkvet, and the firm Vilora bred up to four varieties of chamomile. Breeding work consisted principally of breeding of indigenous Spanish chemotypes with local varieties and was aimed at maintenance of chamazulene content on the original level, but reaching high content of α-bisabolol to the detriment of α-bisaboloxide A and B. This was reached in the period evaluated. Prospective work in this field is aimed at coumarine and flavonoid compounds.

In order to maintain or improve the qualitative characters of chamomile essential oil, maintenance breeding and seed growing on the principles of production process are carried out.

Chamomile is grown on seed plots with a 5-acre area. Seed plots are founded by sowing the seeds of plants in which essential oil contents and composition fulfills the standards of the drug quality. With this objective individual plants are analyzed by thin-layer chromatography, essential oil composition is studied, and plants with detectable amounts of α-bisaboloxides A and B are eliminated. The propagation areas are founded from the seeds produced on seed plots.

Chamomile anthodia disintegrate during the manipulation after harvest and drying. The mass is sieved; receptacles, ligulate florets and disc florets, dust, and flower and seed fragments are removed. Sorted seeds are dispatched packaged.

Varieties

At the present four varieties of chamomile are permitted in Slovakia.

Bona (National Variety Book CSFR 1495 / 1984)

Reproduction concerned the rise of content in (–)-α-bisabolol essential oil at the expense of bisaboloxides, keeping a high level of chamazulene. Reproduction started in 1975 through the cross-breeding of wild-growing material from Spain with the variety Bohemia and following selections on the screening basis for individuals with high content of (–)-α-bisabolol in dichlormethan extracts by reduction with thin-layer chromatography and gas chromatography. The variety testing was executed from 1980 up to 1983.

The early diploid variety was of a smaller size with middle-green leaves and middle-sized reductions. The content of volatile oil equals 0.9%, chamazulene content in essential oil 16.1% and (–)-α-bisabolol 35%. During maintaining breeding (–)-α-bisabolol increased in essential oil by 42.9%.

Novbona (National Variety Book CR reg. No 3052 and SR ev. No 3332)

The variety Bona served as the basic material. The breeding took place in Nová L’ubovn˘a from 1983 to 1990. By the selection through evaluation of the chemotype, inside the variety population, the part of plants with a high content of (–)-α-bisabolol and chamazulene increased.

The early diploid variety consisted of up to small plants, bright green fine leaves, small up to middle size of flower level, middle average of reduction, without tongue-shaped flowers, and including tongue-shaped flowers. In the variety population the (–)-α-bisabolol chemotype is represented by 94%. The content of essential oil in the drug equals 0.9%. The essential oil contains 18.0% chamazulene and 46.1% bisabolol.

Goral (National Variety Book CSFR 1888 / 1990)

As basic material for the polyploid induction through colchicining in 1978, this was used in newbreeding and later registered as Bona. In the following years the population was selected on the basis of analysis for chromosome numbers and through chemotype screening individuals with appropriate characteristics. On the basis of the variety examined from 1986 to 1988, the variety was agreed on in 1989.

In comparison with diploid varieties, the variety distinguishes itself by increased breakdown. The mesh oversize up to 2 mm is 26% in comparison with 10% in the case of the variety Bona. The variety population represents itself as a mixture of chemotypes (35% (–)-α-bisabolol and 65% bisabololoxide). The content of essential oil is 1.1% and chamazulene in essential oil is 24.5% but the content of (–)-α-bisabolol 24% does not exceed the sum of other materials of the bisabolol type. Goral is favored by the farmers because of good harvest characteristics.

Lutea (National Variety Book C R reg. No 3051 and SR reg. No 3333)

The basic material for breeding the variety of the bisabolol type is the variety Goral. In 1987 and 1988 under laboratory conditions and in strong isolation, selected individuals were cultivated on the basis of chemotype screening. In 1989 and 1990 the breeding was implemented under field conditions in Nová L’ubovna.

Middle early tetraploid variety consisted of middle high plants, middle green central leaves, middle height of flower level, high detracted average without tongue-shaped leafs and with tongue-shaped leaves. The variety has a stable chemotype composition of the population (over 92% of (–)-α-bisabolol). The content of essential oil in the drug equals 1.2%, chamazulene in essential oil is represented by 21.2%, and (–)-α-bisabolol 43.3%. The breakdown is on the level of diploid varieties.

Values of secondary metabolites in the period 1991–1995 can be studied in Figure 5.6.2 (the varieties Bona and Novbona) and Figure 5.6.3 (varieties Goral and Lutea).

Principles of Quality: Drug Description

The criteria for quality classes of chamomile flowers are governed by the Branch Standard 86 62 11.

Quality, max. %
Criteria 1 2 3 4
Overripe, crushed flower heads passing through the sieve III (2 mm) 8 16 30 40
Flower heads with stem longer than 20 mm and with leaves 7 10 15 20
Flower heads with stems longer than 40 mm 1 2 3 4
Bare receptacles and undeveloped flower heads Unique 8 12 16
Inorganic impurities 0.5 1 1.5 2
Loss by drying 14 14 14 14
Ash 13 14 15 16
Ash insoluble in HCl solution 4 5 6 7
Content of oil min.% 0.4 0.4 0.3 0.3

In special cases of the use of chamomile flowers, Flos chamomillae, for pharmaceutical needs, the evaluation was performed according to the Czechoslovak Pharmacopoeia IV 1984 and 1987.

Synonym: Flos chamomillae vulgaris is the dried flower head of Matricaria recutita L. species chamomile. It must contain min. 0.4% oil and min. 0.035% chamazulene calculated to guayzulene (1,4-dimethyl-7-isopropylezulene-C15H18-Mr198.31).

Identity Tests

Microscopy: methodical procedure as with DAB10 standard.

Chamomile Flower (Matricariae Flos)

The chamomile flower consists of flower sets Matricaria recutita with the min. content of 0.4%

(V / m) blue volatile oil.

Properties

The drug has an aromatic agreeable aroma. The opened flower heads consist of a single covering, which has the shape of one to three rows of leaves, conical lengthwise, eventually half-round bed (young flower heads), 12 to 20 edge-placed tongue-shaped flowers with white tongues, as well as several dozen central yellow tubular flowers.

Identity Test

A. The covering leaves are egg-formed or spear-formed having bright brown-gray edges. The flower bed is mostly conical and hollow without chaffs. The crown of tongue-shaped flowers consists of a single basal bright yellow or bright brownish and yellow tubular part coming over to white wide egg-shaped tongue. The crown of the tubular flowers is yellow, increasing in height, where it becomes five-pointed having on the base bright brownish to brown colors.

B. The flower heads will be separated into proper parts. Follows test with microscope using chlorhydrate R solution. The outer epidermis of bed flowers has a skin edge composed of one layer of radial prolonged cells and a central zone of chlorophyll-containing structure. Over the structure can be found the epidermis with lengthwise-shaped cells with lateral wavy walls and crack openings as well as glandular hairs. On the edges of guiding beams can be found multiple pointed basic cells with big diameter.

C. The test follows the chromatography method on the small layer (V.6.20.2) using a layer of silicate gel GF 34 R.

D. The identity test. Into reagent flask is placed 0.1 ml of reagent solution with a 2.5-ml solution containing 0.25 g dimethylaminobenzaldehyde in the solution of 5 ml 25% phosphoric acid, 30% acetic acid, and 40 ml water. The solution is heated for 2 min in water bath. After adding 5 ml petroleum ether, the solution is stirred up and the water phase is distinctly green-blue to blue in color.

Purity Test

External state means no more than 25% particles separated by mesh 710.

Foreign matters: (V.4.2). The drug has to correspond to the ash test (V.3.2.16), upper limit 13.0%.

Content Determination

The determination follows the determination of volatile oil content in the drug (V.4.5.8) using 30.0 g drug, a 1000-ml flask, 300 ml water as distillation liquid, and 0.5 ml xylol R as receiver during 4 h distillation with the distillation velocity of 3–4 ml / min. Storage: Protect against light!

Tests of Purity

  • Crushed and overripe flower heads (undersized on the sieve IV): max. 20%
  • Flower heads with the stem longer than 20 mm on other parts of the mother plant (relics of
  • stems, leaves, etc.): max. 8%
  • Flower heads with the stem longer than 40 mm: max. 1.0%
  • Undeveloped flower heads: max. 5.0%
  • Bare receptacles: max. 5%
  • Foreign organic impurities: max. 2%
  • Inorganic impurities: max. 5%
  • Loss due to drying: max. 14.0%
  • Ash: max. 11.0%
  • Ash insoluble in HCl: max. 3%

Mechanization: Picking Technique and Picking Machines

Picking Technique

Manual Picking

This method of picking is sufficient for smaller areas in gardens. It is carried out by cutting, trimming, or combing using combs, which are similar to those used for picking of bilberries. This method of picking is very extensive and labor consuming, but it cannot be replaced by a mechanized method for picking areas determined for production of seed.

Mechanized Picking

Great attention has been paid to the mechanized picking of chamomile during the last 20 years. The question arises about the direct picking in several rows with the width of span from 200 cm to 610 cm according to the type of picking machine. The adapter is equipped with a comb dresser and cutting roller. The proper combing machine is represented by the finger comb with uniform radius of curvature along the entire length of the bar and with constant distances between individual fingers. Flower heads are released by the rotary brush. Flower heads are transported by worm conveyers or by inclined scraper conveyers, or pneumatically using underpressure.