North American ginseng production has been reviewed from both Western and Oriental publications on the most important aspects of the industry, botany, and culture of ginseng (Proctor and Bailey 1987). An international ginseng conference organized in 1994 brought the world ginseng community together for the first time (Bailey et al. 1995). The focus of this paper is to review the present industry with special attention to the challenges that confront the industry in the next decade.
World ginseng production and marketing is at a crossroads. In the marketplace there will be increased competition and traditional methods of marketing will be challenged. For instance, North American producers have sold most of their dried root at the farm to buyers, who export and trade in the Hong Kong market and subsequently distribute and retail. With increased production new approaches are needed to secure guaranteed markets for the North American ginseng industry to remain viable and profitable. Marketing approaches that must be tested include vertical integration, value-added production, and Asian joint ventures.
All phases of ginseng cultivation practices are being questioned. In North America the traditional wooden lath shade is being replaced by black polypropylene shade and every aspect of production from seeding to harvesting and drying is being evaluated for increasing efficiency. In Korea traditional labor sources are vanishing so new shade structures and mechanization are being assessed. As production methods change increasing attention is being given to environmental concerns about fertilizers and pesticides. The ginseng production system in the next decade will include an integration of horticultural, biotechnological, and agrochemical methods in an acceptable economic package that optimizes root quantity and quality and safeguards the environment.
For American ginseng (P. quinquefolium L.) to receive wider acceptance, documented scientific research will be necessary to confirm findings. Work with both American and Korean ginseng will need to be carried out in Western Laboratories. A small start has been made. For instance, Wiklund et al. (1994) showed that P. ginseng prepared as standardized product (Pharmaton SA, Lugano, Switzerland) improved the quality of life in a middle aged Swedish population. In Canada, a Ginseng Research Foundation has been formed by ginseng producers and University researchers to support scientific research on the production, properties, uses and clinical effects of ginseng grown in Canada (Francis 1995). This is a small effort but it indicates recognition that for wider acceptance of ginseng and its products supporting clinical testing is essential. The Swiss pharmaceutical company, Pharmaton SA, a successful marketer of ginseng in Europe since the 1960s, agrees (Faleni 1995).
Oriental ginseng can be distinguished from American using ginsenoside profiles because Oriental contains ginsenoside Rf and American does not (Tanaka et al. 1986; Lang et al. 1993). Protein analysis can be used to distinguish between ginseng species and any included adulterants (see But et al. 1995a for references). Using ginsenoside profiles (Cui et al. 1994), Liberti and Der Marderosian (1978), and Rückert (1980) showed that some commercial value-added products did not contain ginsenosides. In the Liberti and Der Marderosian (1978) study 8 of 23 products did not contain ginseng. In some cases the label indicated that the products contained Siberian ginseng (Eleutherococcus senticosus) or Brazilian ginseng (Pfaffia paniculata) neither of which contain ginsenosides. The inclusion of ephedrine in a product led to an accusation of doping of a Swedish athlete (Cui et al. 1994).
A comprehensive ginseng evaluation program has been initiated by the American Botanical Council to determine if adulteration has occurred in 250-300 commercial ginseng products (Blumenthal et al. 1995). This program should increase consumer confidence and correct problems in manufacturing and labelling. Manufacturing and retailing reports indicate that ginseng has increased its position and profile in the marketplace. For this trend to continue into the next century, all sectors of the global ginseng community will benefit by ensuring that the consumer has confidence in all products on the market.
World ginseng production increased from 1978 to 1985 (Table 1). Since then South Korean production increased to about 5000 t (Table 1) but has remained around this figure (Park and Kim 1995). Annual production figures often reflect growing conditions for the crop, particularly the incidence of disease (see below) rather than change in crop area. The variation in Wisconsin production from 1985 to 1994 (range 519 to 736 t; mean 623 t) likely reflects high incidence of disease rather than grower changes in crop area (Table 2).
In Canada, ginseng production has increased steadily in the last 10 years with British Columbia's first crop sold in 1986 (Table 2). My projection is that Canada's production will not increase beyond present levels.
The major unknown in world ginseng is Chinese production and its marketing. One development in China has been to grow American Ginseng, known in China as Wulong ginseng for local markets to replace costly imports, and also possibly export (Wang et al. 1995). The project was initiated in 1975 and large scale planting is now taking place after much research and development.
Another problem associated with Chinese ginseng root is that of adulteration of American root and value-added products in the Hong Kong market (But et al. 1995b). American Ginseng is 5 to 10 times more expensive than comparable Chinese ginseng in the Hong Kong market, hence the attraction of adulteration. To counter the problem chemical analyses have been developed to allow identity of ginseng constituents of value-added products (Cheung et al. 1994). To protect its interests in the Hong Kong market the Ginseng Board of Wisconsin has organized a labelling system for genuine American ginseng products and has been fairly successful.
Hong Kong continues to be a major importer, distributor, processor, and retailer of ginseng (But et al. 1995b; Evans 1995). Over 80% of American ginseng grown in North America is shipped to the Hong Kong market as is much of the Oriental ginseng from China and Korea. Redistribution of ginseng from Hong Kong is world-wide with major destinations being Taiwan, Japan, Malaysia, Singapore, and the U.S. Hong Kong has become a major center for ginseng trade because of a strong herb industry, a large population of Chinese origin, its strategic location, and a strong finance and communication system. In addition, Hong Kong has become a center for scientific research into Chinese traditional medicine and cures (Evans 1995). The Chinese University of Hong Kong is helping to integrate Chinese and Western techniques and approaches to testing traditional medicines and cures. Ginseng is included in these studies. The prominence of Hong Kong as a ginseng world center may change in the next decade because of its return to China in 1997, changes in the herb industry, and increasing use of Western medications. However, Evans (1995) claims that these changes will be minimal. He points to the major transformation of Southern China that has taken place and the amount of trade and investment between Hong Kong and the mainland.
There has been a strong European market for ginseng since its introduction by Pharmaton SA in the 1960s. Well established markets are in Scandinavia, Poland, Germany, Spain, Holland, Belgium, the UK, France, and Italy. The Eastern European countries, which already have a strong herb and medicinal plant industry, are projected to be receptive to ginseng.
Cultivation is also being attempted in Australia (Baxter et al. 1995) and New Zealand (Follett et al. 1995). Ginseng use in oceania is likely to rise because of increasing immigration from South East Asian countries and demand for natural medicines. Since imported ginseng is used to meet market demands, domestic production, and a move to agricultural diversification are stimulating interest in ginseng.
In the past, North American ginseng growers have sold their crops to buyers who exported the roots to Hong Kong (Chan 1984). These growers have become uneasy about these traditional buyers and are considering developing their own joint ventures with established marketing systems in the Orient. This is a daunting task given the distances, regulations, and cultural complexities involved. Some corporate ginseng growing and marketing has occurred in the last decade e.g. Chai-Na-Ta Corp. (Gill 1995).
The deciduous aerial stem of ginseng has 3 leaflets in seedlings, 5 leaflets per leaf in mature plants with leaf number correlating with age of the plant. Ginseng plants start to flower in the second year. Hu (1976) described the flowers of Oriental ginseng as small, 2-3 mm across; sepals 5, green; petals 5, cream yellow, ovate, apex obtuse; stamens 5, filaments, short; pistil 1, ovary inferior, 2 locular; styles 2, united at base; disk cup-shaped. A typical flowering 4-year old American ginseng plant may carry 30-40 berries in an umbel inflorescence with an average of two cream white seeds, 5-6 mm long and 4-5 mm wide, in each berry.
The ginseng plant has a fleshy taproot which often has two to five laterals and is light yellowish white in color. Dry matter content of the root is about 30%.
Ginseng is cultivated under artificial shade or simulated forest conditions to meet its requirements of about 30% of full sunlight (Proctor 1980; Stathers and Bailey 1986; Proctor and Bailey 1987; Proctor et al. 1988; Proctor et al. 1990; Persons 1995). Artificial shade growing is the more common cultivation method worldwide. Woods growing accounts for about 4% of U.S. production (see Table 2) and provides a high quality root for an expanding niche market (Persons 1995).
The establishment of ginseng gardens in the spring has been difficult because of the inability to store stratified seed from fall to spring. In preliminary work we have been able to stratify and germinate "green" (Aug. harvested) seed in the following May very successfully in the greenhouse (80%-100% germination) but with limited success in the field (30%-40% germination). We have used a combination of seed treatment regimes and growth regulators, particularly gibberellic acid, to achieve this early stratification and germination. We propose to refine our preliminary work so that spring planting is a viable and profitable production system and an alternative to fall planting (Hovius et al. 1995).
There are many aspects of ginseng seed stratification that have not been investigated but which probably influence germination, seedling emergence and crop stand. For instance, there have been no studies on ginseng seed development in the umbel in relation to germination. In other plants with an umbellate inflorescence such as carrot, variability in seedling weight at emergence is associated with variation in embryo length, which is influenced by umbel order and the date of harvest (Gray and Steckel 1983).
Early attempts to tissue culture ginseng from various tissues were reviewed by Proctor and Bailey (1987). Since then callus, shoots, embryoids, and plantlets have been cultured from roots (Jiu 1992), seed (Lee et al. 1990; Arya et al. 1993), protoplast (Arya et al. 1991), and young flower buds (Shoyama et al. 1987) of Oriental ginseng. The two reports for American ginseng were of root cultures producing callus, embryonic calli, and plantlets (Wang 1990) and leaf and root explants giving somatic embryos (Tirojah and Punja 1995). Although considerable progress has been made much more research and development is needed before tissue culture regeneration systems can replace seeding.
The in vitro culture of Oriental ginseng cells or tissue for the production of ginsenosides has been successful (e.g. Furuya et al. 1983; Choi et al. 1990; Inomata et al. 1993; Choi et al. 1995). Similar systems for American ginseng have not been reported. For ginsenoside production from ginseng cell cultures to be commercially successful large amounts of ginsenosides must be produced rapidly. Choi et al. (1995) selected two ginseng cell lines, KGC 13 and KGC 15, for ginsenoside production and of these KGC 13 produced the highest level reported to date with 80 mg/15 ml culture medium in 34 days. Their work also suggested that some cultured lines may produce more ginsenosides than intact roots. Further work is needed to check the stability of selected lines and details of bioreactor culture.
Plant cell culture for ginsenosides may have a place in production of these metabolites for inclusion in value-added products. It will complement field culture of roots rather than replace it since consumer preference is for whole roots.
A plea by Proctor and Bailey (1987) for authoritative guides or bulletins on ginseng diseases, particularly for North America, has been answered e.g. Parke and Shotwell 1989; Brammall and Fisher 1993; Anon. 1995; Reeleder and Fisher 1995a, b). An illustrated compendium, Diseases and Pests of Vegetable Crops in Canada (Howard et al. 1994) includes discussion of 8 fungal diseases, 3 insect pests, 3 nutritional and other disorders, and nematodes and slugs in ginseng. A more extensive list for Korean ginseng is presented in Table 3.
Research on diseases in ginseng in North America has received increasing attention in the last decade. Darmono and Parke (1990) characterized the chlamydospores of Phytophthora cactorum and Darmono et al. (1991) isolated and determined the pathogenicity of Phytophthora from forest soils and ginseng gardens. Reeleder and Brammall (1994), working on damping-off and root rot diseases, demonstrated that isolates of Pythium spp., Cylindrocarpon destructans and Rhizoctonia solani reproduced symptoms observed in the field. However, new pest problems are also being reported. Hudelson and Parke (1995) reported an extreme problem in establishing ginseng seedling stands. Healthy-looking seedlings develop a red discoloration of the foliage and the roots rot and the disorder has been called "mystery seedling disease" (MSD). Pathogenicity trials suggest the involvement of Cylindrocarpon, Pythium, and a fungus putatively identified as Septonema. Control of MSD has been difficult with soil fumigation and fungicides having only limited success.
Insect problems in ginseng are minor compared to diseases (Table 3). A new insect problem is pit-making pittosporum scale, Asterolecanium arabidis (Signoret) which causes depressions in the stems at the feeding sites and distorted shoot development (Schooley pers. commun.). It is thought that the scale has been carried by birds into the ginseng gardens from adjacent woodlots containing host plants.
Globally, the commercial cultivation of ginseng requires the application of pesticides. Registered pesticides for Korean pests are listed in Table 3. Pesticide evaluation and registration in other countries is on-going. In Canada some pesticides are registered as in Korea (iprodione and mancozeb), some await full registration (metalaxyl), whereas others (chlorothalonil and pentachloronitrobenzene) are registered in Canada but not in Korea (Anon. 1995).
Ginseng growers are concerned about pesticide use and residues and are continually looking for new strategies for pest control. For example, Yu and Ohh (1995) reported that Korean ginseng growers use soil amendments of antagonistic microbes plus organic matter to reduce root rot. In North America, Joy and Parke (1995) are investigating the biological control potential of Burkholderia cepacia, strain AMMD, for Alternaria leaf blight. This disease is a major problem worldwide (Anon. 1995 and Table 3) and the preferred control chemical is mancozeb. A biological control agent as an alternative to mancozeb is needed.
Another approach to disease control in ginseng would be to breed resistant types. This is very long-term because of breeding difficulties such as the 20 months required for seed germination and yield assessment in a perennial plant. Biotechnology may have a place in the breeding of ginseng. Agrobacterium-mediated transformation has already been achieved in ginseng (Lee et al. 1995; Tirajoh and Punja 1995).
A major problem in ginseng cultivation is that a second planting made in the same ground will fail, a phenomenon known as "replant disease." Growers recognize the problem and do not replant the same land. This poses problems where there is a limited land base for cultivation.
Ginseng replant disease is very complex (Li 1995; Yu and Ohh 1995) with no single factor being responsible, even though Ohh et al. (1992) confirmed that Cylindrocarpon destructans was the causal organism leading to replant problems.
A concerted, international effort is needed to solve the replant disease problem. Such a solution will likely include biological, ecological, and chemical approaches. The characteristic features of ginseng replant disease must be understood. For example, does the disease induce leaf symptoms and, if it does, is it in year 1, 2, or 3? Does the disease inhibit root growth leading to weak, necrotic, and poorly branched roots with altered shoot, root ratio? Does it cause mineral nutrient imbalances? How long do the pathogens persist in the soil?
The root-knot nematode (Miloidogyne sp.) reduced the growth of naturally infested 6-year old Korean ginseng roots by reducing fresh and dry weight and root length and diameter (Ahn et al. 1983). Vrain (1993) reported similar results for American ginseng. Soil fumigants for nematode control are recommended (Anon. 1995) and may also reduce ginseng replant disease. However, it is expected that use of soil fumigants will be prohibited in the near future. Hence, new approaches that are more environmentally acceptable are needed. For instance, pre-planting with plants having nematocidal properties e.g. members of the Compositae (Gommers 1973), and steam pasteurization need to be evaluated. Availability of self-propelled field bed steamers makes this approach attractive.
In the establishment of ginseng gardens bed plows and bed groomers are used extensively and are now fairly standard throughout the North American industry. The sowing of seed has progressed rapidly in the last decade. The one-row, hand-held Planet Junior which gave both a crude-sizing capability and a spreading device that produced scattering of the seed to reduce bunching has been replaced with tractor mounted multiple-row seeders. Although these units allow seeding of 2 ha or more per day there is still an opportunity to improve plant stand and final root quality using sized seed and precision seeding.
Straw spreaders range from the single spreader of small rectangular bales to large spreaders using large rectangular bales (1.2 x 1.2 x 2.4 m). The latter totally mechanize the straw spreading system, including the handling of the bales.
The traditional wood lathe shade system is rapidly being replaced by plastic shade systems. The plastic system requires fewer shade support posts thus allowing fewer and wider passes with the sprayer and fewer posts to purchase and install. Some growers are evaluating retractable shade. Light sensors or time clocks are being used to withdraw shade. Shade removal may allow drying out of the foliage in gardens, thus reducing disease incidence. Possibilities exist for improving yield by allowing more light to reach the plants under cloudy conditions, or earlier or later in the day. Possibly all artificial shade for ginseng growing will be plastic by the turn of the century.
Many different types of sprayers are used. The most common type uses a hydraulic boom; sophisticated sprayers have large spray tanks and complete hydraulic drive systems in self-propelled units.
The objective in root harvest and post-harvest is to mechanize the complete process. The most advanced diggers convey the root into bulk bins. These bulk bins can be moved with fork lifts to cold storage or processing lines. At the processing lines the bins are mechanically dumped for root washing, inspection, and loading onto drier trays. These drier trays can be moved mechanically into dryers. Most ginseng driers in North America are modified tobacco kilns with the necessary technology being taken from the tobacco industry. After drying, the roots are inspected again and loaded into drums with automatic weight recording. The system described above is the one that all growers should reach within the next decade.
The marketplace demands high quality roots. A large quantity of low quality, poorly dried and inappropriately shipped roots destroyed the Canadian ginseng business for about 100 years from 1750 to 1850 (Hellyer 1984). Most problems leading to low quality roots start with the grower and can be avoided. These include inadequate soil drainage, untimely and poorly applied pesticides, and neglect of good sanitary practices.
A range of chemicals have been isolated from ginseng with the ginsenosides receiving most attention. Oriental testing has shown that the biological activity of the ginsenosides appears to match traditional and empirical claims and uses. Scepticism still remains, particularly in the West, although sales of ginseng products are rising steadily. Extensive clinical testing is needed to sustain and expand ginseng use.
Seeding is still the major method of propagation of ginseng in spite of some success in culturing different parts of the plants. A major remaining challenge in tissue culture is to produce flowering plantlets which give viable seed.
The production of ginsenosides in large-scale plant cell culture has been successful. More remains to be done in selecting cell lines that produce large amounts of ginsenosides quickly in bioreactor culture.
Opportunities exist for shortening the stratification period of American ginseng seed to allow spring planting. This may reduce disease incidence. Since only one-third of ginseng seed sown ultimately produces plants harvested after 3 years any approach that reduces disease incidence and improves seed germination, seedling emergence and crop stand must be pursued.
Disease is the major problem in ginseng cultivation from seed stratification, soil preparation prior to planting, right through to drying of the roots. Replant disease remains as an unresolved problem and needs full characterization and new approaches for control. Much progress has been made in research and related extension activities in disease control. Continued progress is expected with the new, concerted global attack on disease research and investigation of new strategies. Work on biocontrol of diseases shows promise. The application of Agrobacterium-mediated transformation for disease resistance is interesting and exciting.
Pest control studies must continue to investigate timing and amount of pesticide applied, to include integrated pest management, and to consider new methods of soil fumigation. Use of soil fumigants will be prohibited. Steam pasteurization is more environmentally acceptable than chemical fumigation and may be a replacement for it.
Decreased labor populations and increased associated costs for ginseng production are causing rapid mechanization in every aspect of the ginseng industry. Engineers, machinery dealers, and fabricators, and growers are being challenged to increase efficiency by mechanization.
At present ginseng production is an established part of North American medicinal crops industry. Trade could expand if ginseng finds an increasing market here and abroad.
|Production in dry wt(t)|
|Country||Production in dry wt (t)|
|Common name||Scientific name||Chemical applied for controly|
|Alternaria blight||Alternaria panax Whetzel||Bordeaux mixture, Captafol|
|Anthracnose||Colletotrichum panaciocola Uyeda et Takimoto||Iprodione, Mancozeb, Polyoxin|
|Grey mold||Botrytis cinerea Persoon|
|Phytophthora blight||Phytophthora cactorum (Cohn.et Lebt.) Schroter||Benomyl Metalaxyl|
|Rhizoctonia stem rot||Rhizoctonia solani Kuhn|
|Root rot complex||Fusarium solani (Mart.) Sacc.||Rizolex Benomyl, Captafol, Gyron|
|Seedling rot||Phythium ultimum Trow|
|Sclerotinia white||Sclerotinia sclerotiorum (Lib.) DeBary |
Sclerotinia inor Jagger
|Phoma stem blight||Phoma panacis Nakata et Takimoto||Rizolex|
|Damping-off||Rhizoctonia solani Kuhn|
|African mole cricket||Gryllotalpa africana Palisot de Beauvois||Deltamethrin|
|Black cutworm||Agrotis ipsilon Hufnagel|
|Common cutworm||Agrotis fucosa Butler|
|Dark gray cutworm||Agrotis tokionis Butler|
|Japanese wheat wireworm||Agriotes sericeus Candaze|
|Korean black chafer||Holotrichia diomphalia Bates||Diazinon, Etoc|
|Larger black chafer||Holotrichia morosa Waterhouse|
|Small velvety chafer||Serica orientalis Motschylsky|
|European corn borer||Pyrausta nubilalis Hubner|
|Rodents and other pests|
|Striped field mouse||Apodemus agrarius Thomas||Brodifacoum|
|Snail||Bradybaena sieboldiana Pfeifer||Bordeaux mixture|
|Potato rot nematode||Ditylenchus destructor Thomas|
|Northern root-knot nematode||Miloidogyne halpa Chitwood||Mocap|