Cultivation of Echinacea in Europe: Field Practices

Nutrient Supply

Information on nutrient requirements and fertilization of Echinacea species is very limited. In the early cultivation handbooks, the fertilization instructions are quite general. German writers have proposed mixing fertilizers in 100 to 200 kg/ha at ratios of N:P:K = 12:12:20 with additional compost between the rows every spring.

In 1986, Bomme published the first growing instructions on E. purpurea and E. pallida with the following fertilization recommendation: nitrogen, 150 to 180 kg/ha; phosphorus, 70 to 100 kg/ha; and potassium, 220 to 250 kg/ha. This recommendation was followed by other cultivation handbooks in Europe. In Hungary, Praszna (1993) proposed the same doses with additional 30 tons/ha of manure in the previous autumn. In Poland, the first growing instructions proposed nitrogen, 60 to 80 kg/ha; phosphorus, 40 to 60 kg/ha; and potassium, 80 to 100 kg/ha.

According to Dachler and Pelzmann (1999), in soil with good conditions, phosphorus and potassium seem to be suitable in doses 70 and 150 kg/ha, respectively. The total quantity of nitrogen is 120 kg/ha, which is applied after sowing or transplanting, and after the first cut if a second cut is expected.

Detailed Experiments

Detailed studies on the fertilization of Echinacea started during the 1980s. The first fertilization data were published in northern Italy, where a fertilization trial was carried out using E. pallida in 1984-1985. The experimental area was in a mountain environment with acidic (pH = 4.95) and nonirrigated soil. The applied nitrogen quantities were 0, 100, and 200 kg/ha and the phosphorus and potassium doses were 0 and 100 kg/ha, respectively. Bezzi and Tessari (1989) found a positive effect of potassium on root production. The average root yields ranged between 1.1 to 1.3 tons/ha, while with higher doses of potassium, the root yields ranged between 1.5 to 1.9 tons/ha. The content of echinacoside — varying between 0.296% and 0.951% — was positively affected by the nitrogen and phosphorus.

The detailed nutrition requirements of the three Echinacea species were determined by German researchers. According to their results, 1,000 kg of fresh Echinacea plant biomass contain 3 to 9 kg of nitrogen, 1 to 2 kg of phosphorus, and 4 to 8 kg of potassium. The quantities of these main elements vary with the species and plant parts. The highest quantities of the main elements were extracted from E. purpurea, followed by E. pallida, and the lowest was from E. angustifolia (). In calculating the applied fertilization level, these figures have to be corrected for by the actual nutrient level of the soil, demonstrated by soil analyses. The calculated, appropriate phosphorus and potassium quantities for fertilization must be added in autumn and the appropriate nitrogen doses should be added separately in spring before transplanting, after the start of growth of young plants and after the first herb harvest.

In Poland, in a detailed experiment, the highest yield was obtained with N = 100, P205 = 60, and K20 = 100 kg/ha. The effects of the fertilization on the dried root yield were evident during the second and third growing years (1.94 and 1.99 tons/ha, respectively), but decreased in the fourth year (1.35 tons/ha). The effect of the lack of nitrogen was more significant in the dry herb yields, which decreased linearly, that is, 8.38, 3.72 and 2.38 tons/ha, respectively. The total contents of the polyphenolic compounds ranged, in the herbs between 3.7% and 5.0% and in the roots from 1.6% to 3.5%, but the various fertilization levels had no effect on the contents of the polyphenolic compounds.

In another Polish experiment, the effect of two soil types on the yield was compared in pot conditions. The biomass yield depended on soil type and level of fertilization. The total biomass was higher on loamy soil by 64% to 71% in the first and second experimental years, but the contents of phenolic acids (chlorogenic, caffeic, and ferulic acids) were higher in sandy soil.

Organic Fertilization

Much less data are available on organic fertilization of Echinacea. In Finland, composted and granulated chicken manure (Biolan) is used regularly in a dose of 2.5 tons/ha in organic cultivation (N:P:K = 4:1:2). Incorporating this quantity into soil before planting seems to be suitable for 2-year growth.

Weed Control

Chemical Weed Control

Although Echinacea grows in meadow ecosystems in wild places, it is not weed tolerant in cultivation. Therefore, although weed control is a very important factor throughout the entire cultivation period, it is especially important in the first year. In small cultivation areas, mechanical weeding is an ideal and easy way to keep populations free from weeds. However, in the case of larger, industrial production, chemical weed control becomes necessary, especially if direct sowing of seeds has been employed.

In Europe, registered herbicides exist only in Poland where several experiments were carried out for elaborating chemical weed control methods for E. purpurea (). Among 18 tested herbicides, three preparations have given good weed control alone or in combinations. Azogard (prometryn) in the dosage of 2.0 kg/ha provided good control of broadleaf weeds; Kerb 500 SC (propyzamid) in the dosage of 2 kg/ha controlled grass and broadleaf weeds; and Fusilade Super (fluazifop-P-butyl) in the dosage of 1.51/ha controlled grass weed. The residuals of these herbicides in the raw material were at a permissible level.

Weed Control in Organic Cultivation

Time-consuming manual weeding is one of the most significant factors in production cost and it is the main limiting factor in field size for cultivation. Mechanical weeding and the use of various mulches comprise two more practical methods for large-scale cultivation.

In larger-scale organic cultivation, the use of plastic mulch is common, since its spreading is mechanized at present for strawberry and cucumber cultivation. Plastic mulch can decrease the labor cost of weed control by 70% to 80% and produces a 114% increase in fresh plant weight. Cleaning rows between plastic mulch rows could be easily mechanized as well using regular lawnmowers. The heat accumulation in the soil under the plastic mulch in cooler areas is an additional advantage of this method. In warmer climates, use of black plastic mulch could be a disadvantage since it retains heat. Consequently, growers need to prepare for irrigation.

Crop Protection

Thus far, only a few diseases and insect attacks have been observed in cultivation areas of Echinacea. Li (1998) concluded that plant disease does not seem to be a problem with Echinacea in North America. However, it is generally expected that during continuous cultivation, some new diseases and insects will occur. Only a few diseases have been reported in Echinacea: leaf spots caused by either Cercospora rudbeckii PK or Septoria lepachydis Ell&Ev, and root rot caused by Phymatotrichum omnivorum (Shear) Dug. In Poland, Kucharski (1997) reported that Alternaria alternata was identified in E. purpurea cultivations.

For preventing disease infections, treatment of seeds before sowing is proposed in some countries. The preparations are Polyram-Combi for E. purpurea and E. pallida, in 0.2% concentration for 24 hours in Germany. In Poland, Dithane M-45 or Penncozeb 75 WG in a dose of 3 to 5 g/kg of seed, or Dithane 455 SC or Penncozeb 455 SC in a dose of 4.5 ml/kg of seed are proposed. Kucharski (1997) listed the observed insects on E. purpurea in Poland: Philenus spumarius, Phytomyza atricornis, and Liriomyza strigata. In a coneflower growers manual, Polish experts proposed a wide range of insecticides as effective against these insects. The use of chemical preparations in plant cultivation is regulated by the authorities and varies among countries. Plant protection in organic cultivation is problematic at present.

Harvest and Yield

Harvest times of Echinacea depend on the propagation methods used, age of plantation, and species. The accumulation of biomass during the initial growing years is quite low. According to a Romanian study, total fresh plant weights from transplanted seedlings were 414 g/plant of E. purpurea and 184 g/plant of E. pallida. The weights increased linearly to the third year, reaching 1422 g/plant fresh weight of E. purpurea and 1210 g/plant of E. pallida ().

Good adaptation of E. purpurea to various climatic conditions shows that fresh plant biomasses were similar in Romania and Finland after the second year. The total fresh plant weight in Finland ranged between 547 to 870 g/plant, and in Romania, the average weight was 698 g/plant.

According to German experiences and recommendations, harvest possibilities of the main Echinacea species are summarized below.

Herb harvest, first year of cultivation: The optimum harvest time occurs when the main flowers are in full flowering. Of the three species, only E. purpurea flowers in the first growing year in central Europe. The other two species may have flowers at the end of the summer. In the northern part of Europe (e.g., Finland), in the case of transplanting in early June, there are no flowers at all during the first year. In the propagation years, flowering and harvesting times are generally in the early autumn: for E. purpurea, October; for E. pallida, the end of September or beginning of October; and for E. angustifolia, the end of September.

Second to fourth years of cultivation: After the propagation year, flowering of well-established populations starts earlier. The optimum harvest time occurs when the plants are in full flowering: for E. purpurea, the end of August or beginning of September; for E. pallida, the end of July or beginning of August; and for E. angustifolia, the end of July. For optimum contents of active ingredients, it is proposed to harvest as many full bloom flowers as possible. During autumn, a second harvest of the herb biomass may be achieved, but the proportions of the flowers then are generally lower. The stem height for cutting should not be lower than 10 cm aboveground. Lower cutting may result in poor overwintering and less growth in subsequent years. The times of the second harvest should not be too late in the year. In Poland, harvest in the second and third years is usually carried out between September 18 and 24, but in the fourth year, it is earlier, such as August 20. The harvest of herb biomass in smaller plots is carried out by hand, but on a larger scale, machinery is used.

Root Harvest

The root size of E. pallida and E. angustifolia is suitable for harvest beginning after the second growing year. According to Romanian and Polish experiences, root harvest during the end of the third year results in higher root yields. In the case of good growing conditions, root harvest of E. purpurea propagated from seedlings can occur in the first year.

The root harvest can be combined with the herb harvest as well. This means that before the root harvest, the herb could be utilized without harmful effects on root quality. The roots can be harvested in smaller areas by hand but on an industrial scale, machinery must be used. From the practical point of view, poor root harvests depend on improper root depth. Horizontally, the roots of E. angustifolia are concentrated in a region extending 150 mm on either side of the row. More than 90% of the roots of 2-year-old plants could be dug out from a depth of 27 cm. The roots of 3-year-old plants are deeper, since 78% and 92% of the total root yield are obtained from the 36-and 45-cm depth.

Yields

The three Echinacea species differ in terms of biomass production and end yields. In general, E. purpurea is the highest-yield species, and the lowest-yield species is E. angustifolia. The yields of E. pallida range between these two.

Field cultivation yield depends on several factors such as age of plants, climate, place of cultivation, and cultivation methods used. On the basis of experimental and practical cultivation results, Bomme (2000) presented the possible yields of the three main species in Germany. According to these results, in the optimal cases, the yields of E. pallida could be nearly as large as those of E. purpurea, producing 54 tons of fresh and 10 to 12 tons of dry herb/ha. The drying ratio between the fresh and dry herb yield of E. purpurea is generally 3.8 to 4.9:1, and for E. pallida, 4.0 to 5.5:1. Due to the higher dry matter content of the roots, the drying ratio of the root yields is lower, ranging between 2.6 and 4.0 to 1.

Seed Production

There is no specific report dealing with seed production of Echinacea. Only Lithuanian studies have reported seed productivity of E. purpurea (). Collection of seeds is carried out during the second through the fourth years of plant age. Seeds must be collected from well-developed, healthy, and strong individual plants. One flower head contains 356 to 563 tubular flowers, but only 36% to 61% of them produce ripened seeds.

The best seed collection time is when seeds are biologically ripe, 1 to 1.5 months after flowering, in August and September. During this time, the cones of the dry flowers are brownish in color. The best weather for seed production occurs when the air temperature is relatively high, with abundant sunny days and moderate quantities of rain. The harvest is carried out manually, selecting for the largest cones.

The harvested cones are kept in a dry place for a week and then the flower heads are crumbled mechanically. Larger quantities of flower heads are simultaneously crumbled by using a grain combine. The crumbled masses of seeds and stems then must be separated and seeds are finally cleaned by machine.

The separation of seeds from other parts of the flowers is somewhat difficult due to their similarity in weight and size. A laboratory separator for E. purpurea (Kamas Westrup LA-LS, Sweden) has a 4-mm hole size in its upper and middle screens, and 0.1 mm in the lower screen. The optimum speed of its motor is 390 rpm. The clean seeds are stored at a constant temperature in a moderate-humidity chamber.

Mechanization

Mechanization is the main mechanism involved in large-scale cultivation of Echinacea. Without proper machinery, the cultivation areas and the quantity of the harvested raw materials remain small and costly, and labor intensive. Nevertheless, the grower must ensure that the machinery employed does not negatively affect the quality of the raw materials. The solutions used in mechanizing individual technological elements are quite variable, and reflect the machinery used in different countries, cultivation areas, and farms. Generally, machinery specific to medicinal plants does not exist nor has it been designed. Therefore, all existing machinery at the local level must be tested, and if necessary, adapted for the requirements of Echinacea. Machinery used in different aspects of cultivation is summarized below.

Soil preparation: plough, harrow, rotary harrow, rotary cultivator, tiller, bed ridger, bed lister

Fertilization: manure spreader, fertilizer spreader

Propagation: one-row manual seed driller, two- to five-row precision seed driller, greenhouse seed driller, pot filling and seeding line

Transplantation of seedlings: one- to four-row transplanter (for vegetables)

Crop protection: plant protection sprayer

Mechanical weeding: plastic film layer, interrow cultivator, row rotary cultivator, rotary weeder, rotary hoe, potato ridger, harrow, harrow comb

Herb harvest: self-loading trailer, flail, chopper, cutterbar unit, swather, rotary mower

Root harvest: carrot, sugarbeet harvester, potato elevator digger with windrowing attachment, root spinner, shaker digger, root washing machines, rotary drum washer, root cutting machines

Seed harvest: standing combine, crusher, threshing machine, seed dressing machine

Postharvest processing: chopper, cutter, press

Drying: dryers, batch dryer, conveyor belt dryer

Packaging: packaging machine

Quality Requirements

For Echinacea end products, there are pharmacopoeia standards or monographs at the national level; for example, in Germany such requirements are found in the Deutsches Arzneibuch (DAB). In Europe, monographs issued by the European Scientific Cooperation on Phytotherapy (ESCOP) also include E. purpurea radix, E. purpurea herba, and E. pallida radix (ESCOP, 1997). However, there are no general, specific quality requirements for field cultivation. Medicinal companies have their own quality requirements; growers supply raw materials that must comply with them. These companies are mainly concerned with the authenticity of the plants cultivated, microbiological purity, and presence of pesticide residues and heavy metal contents of the raw materials.

Toward ensuring high-quality raw materials and end products for the medicinal industry, a strict compilation of regulations known as Good Manufacture Practice has been accepted in European Union countries. Significant efforts were then focused on the preparation of similar guidelines for field cultivation of medicinal plants as well, to ensure appropriate raw materials from the field. The results of efforts until 1989 were compiled by Franz (1989), and the final accepted guidelines of Good Agricultural Practices were published by Mathe and Franz (1999).

Bertalan Galambosi “Cultivation in Europe” (2004)