influence of soil preparation, seedling rates, and organic
mulch on the production of woods-cultivated ginseng
North American ginseng (Panax quinquefolius
L.) has long been recognized as a valuable horticultural crop because of the properties of
its roots for both herbal and medicinal purposes. The wild root is generally
described as having the highest quality. Unfortunately, over-harvesting and inappropriate
management in 1800's led to its decline. Today, ginseng production can be divided in three
distinct categories: 1- wild simulated root, 2- woods-cultivated
root, and 3-
field-cultivated root. The aims of this study were to compare different treatments in
natural forests and in pesticide and chemical free environments in order to produce high
quality roots. To achieve this goal, three soil preparations (1- wild
tillage, and 3- preparation of beds), three kinds of organic mulch (1- forest
2-decidious leaves, and 3-wood chips/leaves), and three plant densities (25 to 35 kg per
ha) were studied. The effects of these treatments on germination rate, plant
mortality and root morphology were analysed on seedling. Our results have shown that mulch
type has an effect on plant mortality, whereas soil preparation (tillage and bed
preparation) improved the germination rate and growth of ginseng
seedling. Plant density
had no significant effect for the first year of growth. Data will be discussed in terms of
improved crop management for better plant growth.
- Ginseng, an obligate shade plant, is grows
naturally in broadleaf forests of Northern Asia and North America (Proctor and Bailey
1987). American ginseng (Panax quinquefolius L.) ranges from southeastern Canada southward
to the Carolinas and Georgia and westward to states bordering the Mississippi River.
Habitat destruction through the cutting of deciduous forests and intensive harvesting for
their medicine properties, however, have contributed to its progressive disappearance in
North America (Charron and Gagnon 1991). North American ginseng has long been recognised
as a valuable horticultural crop because of the properties of its roots for both herbal
and medicinal purposes. Traditional Asian medicines use this valuable root extensively.
Data from Statistics Canada indicate that the average Canadian export price on
field-cultivated ginseng root in 1997 was 23.93 Canadian $/lb. For 1996, the U.S. exports
of wild ginseng root (including wild simulated root, woods cultivated ginseng and wild
root altogether) were also recorded as having an average price about 242 Canadian $/lb.
Unfortunately, new fungal diseases affecting large-scale ginseng fields are now
threatening the profitability of this culture. Moreover, ginseng root quality has
decreased noticeably over the last few years, resulting in significantly lower prices.
Growing ginseng in its native forest environment is another approach, which is less
expensive, and produces high quality roots in pesticide and chemical free environments.
- Numerous studies have been conducted on the
ecology of natural populations of ginseng (Charron and Gagnon 1991, Lewis and Zenger 1982,
Stathers and Bailey 1986), reproductive biology (Lewis and Zenger 1982), chemical
composition (Kim et al. 1995, Ma et al. 1994), medicinal properties (Carlson 1986),
field-cultivated growth, yield, photosynthetic rate, respiration and transpiration under
various solar radiation and/or temperatures conditions (Konsler 1986, Lee et al. 1980,
Proctor and Tsujita 1986). Unfortunately, the wild simulated root, and woods-cultivated
root production techniques have received limited attention. Quantitative differences in
total ginsenosides and qualitative differences in individual ginsenosides between wild and
cultivated plants have been reported (Betz et al. 1984) which might be attributed to
physiological stresses and differences in growth rate (Konsler et al. 1990). Woods growing
is potentially profitable in the United States and is now practiced by more people
(Persons1 1994). In New Zealand, Smallfield and al. (1995) have shown that American
ginseng can be grown successfully under canopies of Pinus radiata planted on volcanic ash
soil in the Central North Island. Cultivating ginseng within natural forest (Korean pine
forests) is the future direction for ginseng plantations in China (Wang et al. 1994).
- There are two different approaches for growing
ginseng under natural forest shade: 1- the wild-simulated method (minimal disturbance to
the forest floor), and 2- woods cultivation (preparing cultivated beds) (Persons1 1994).
Wang et al. (1994) observed that root weight decreased with increasing shade density and
that soil preparation could produce an increase in ginseng weight when ginseng was
cultivated for 7 years under different forest canopies using the seed scattering method
with no soil preparation or with soil preparation. Root characteristics also changed with
the type of forest (fertility, climate, shading).
- It is well known that the natural leaf mulch
under the forest canopy plays an important role in the growth of ginseng as it conserves
moisture during dry periods in the summer and provides protection for roots from
excessively low soil temperatures during the winter (Stathers and Bailey 1986). A study
done by Konsler (1982) during 4 years has shown that oak and poplar mulches produced the
highest yields while straw was among the lower yielding mulches. Roots from pine needle
mulch tended to be among the largest during the first two years but by the fourth year
were among the smallest while wheat straw and hardwood leaf mulches consistently produced
- Root growth and incidence to diseases are
strongly influenced by plant spacing. Under field growing conditions many studies have
been done in order to optimise plant spacing (Konsler 1982, Konsler and Shelton 1984).
However, little is known about the response of American ginseng to plant spacing in its
woodland habitat. The objective of this study was to study the effects of soil
preparation, plant density and mulches on germination rate, plant growth and mortality and
root morphology for the first year of ginseng growth under its natural forest
- Experimental Methods
- Experimental site
- The experiment was conducted in a sugar
maple-beech forest located at Ile d'Orléans, Québec, Canada (lat. 46.58, long. 70.58).
The woodland soil is a loam-clay with 11.7 % organic matter and pH of 4.6. Total
precipitation for may to September 1997 is 436.2 mm. Normal daily air temperatures for the
month of May, June, July, August and September are 15.9, 22.8, 24.9, 24.3 and 17.7 °C,
respectively. Natural forest canopies provide 70-80% of shading. Preparation of the wooded
sites consisted in the removal of all brush and small saplings. For wild-simulated
planting, the leaves were raked aside and the soil surface was loosened on 2.5 cm with a
heavy-tined rake. Seeds were scattered, raked in, mulched by returning the original leaf
litter, and left to grow naturally. In wood tilled cultivation, seeds were planted 2.5 cm
deep and mulched with natural leaf cover or according to the mulch
treatments. Beds of 9 x
2 x 0.10 m were made and seeds planted 2.5 cm deep according to the plant spacing
treatments. Fifteen cm of wood chips or deciduous leaves mulch was put on individual
plots. In the second experiment, beds of 11 x 1 x 0.10 m were made and seeds planted 2.5
cm deep according to the plant spacing treatments.
- In the first experiment, three soil preparation
treatments (1- wild simulated, 2- tillage on 15 cm depth, and 3- preparation of beds on 10
cm), and three plant densities (1- 25 kg per ha, 2- 30 kg per ha, and 3- 35 kg per ha)
were compared. The experimental design was a completely randomized blocks with three
replications and two repetitions for a total of 54 plots. In the second
soil preparation treatments (1- wild simulated, 2- tillage on 15 cm
depth, and 3-
preparation of beds on 10 cm), and three kinds of organic mulch (1- natural forest
2- 15 cm of deciduous leaves, and 3- 15 cm of wood chips/leaves
mixing) were studied. The
seedling rate for the second experiment was 30 kg/ha. The experimental design was a
completely randomized blocks with four replications for a total of 36 plots. Each plot of
the first experiment was 2 x 9 m in size and 2 x 11 m for the second
Stratified American ginseng seeds were purchased from commercial source and planted in
- Monitoring, sampling and
- The number of seedlings found in a 2 m2 in each
plot was recorded weekly during the 1997 growing season (09/06/97 to 07/08/97). Nine
plants per experimental unit were dug in mid-August and stem
length, root and shoot fresh
and dry weights measured as well as leaf area. Morphological analysis of nine plants per
experimental unit was done with WinRhizoÔ software (Régent Instruments,
The GLM procedure was used for the contrast analysis of this two factorial experiments
(SAS Institute Inc.). The contrasts were determined a priori and the number of comparisons
was equal to the degrees of freedom of the treatments.
Effect on emergence and
the first experiment, soil preparation treatments had a significant effect (P=0.01) on
plant emergence, mortality and survival while plant densities did not affect significantly
these parameters (table 1).
Soil preparation gave better results than wild simulation (more than twice as high
emergence). However, large variation within experimental units was observed. The soil
preparation increased drainage and soil temperature. Seed germination occurred when soil
temperature reached 5 oC (Wang et al. 1994). Plant spacing had no effect on these
parameters very likely because the seedlings were too small to observe density effect.
Under optimal conditions, the germination rate of stratified seeds is ~ 60-70 % (Oliver
1996). With densities of 25, 30 and 35 kg/ha and a germination rate of 65 %, the emergence
rates are 54, 64 and 75 plants/2 m2, respectively. The poor results obtained could be
explained by the cold rainy conditions that prevailed in spring 1997, by insufficient soil
drainage and by seed diseases. In fact, pathogens propagation, causing damping-off such as
Rhizoctonia, Pythium, Fusarium and Phytophtora, are favored under cold and wet conditions
In the second
experiment, wood chips/leaves mulch favored plant emergence (P=0.01), more than twice as high emergence
compared natural forest floor and 4 times with deciduous leaves. The wood chips mulch is
less humid than the two other ones, and might increase
temperature. Adding deciduous
leaves to the forest floor is generally no recommended because soil humidity increases and
as a consequence, the thick layer of mulch affects seedlings
emergence. The slugs were
responsible for most of the mortality rate. Their impact is lower when wood chips were
used because this mulch has an abrasive effect on the slugs (Oliver 1996).
Effect on growth and
Soil preparation treatments
had a significant effect (P=0.05) on plant growth and root morphology (Tables 3, 4 and
5). Bed cultivation and soil tillage
increased leaf area by 16% while shoot and root fresh weights increased by 18-24% and 40%,
respectively. No significant effect was observed on stem length and shoot and root dry
weights. The total length (cm), area (cm2) and volume (m3) of smaller roots (<1 mm)
were 80-83%, 60-63% and 44-50 % higher, respectively, under disturbed soil (tillage and
bed cultivation) compared with the not-disturbed soil (wild simulated plants;
However, no significant effect of soil preparation on
these parameters was found for bigger roots (>1 mm). Moreover, root projected area
(cm2), and the number of root apex and root divisions increased by 55-60%, 36-51% and
60-65%, respectively, under disturbed soil in comparison with the not-disturbed soil while
mean root diameter decreased by 13-22% (carrot shaped with soil preparation for the first
year of growth). These results suggest that under disturbed soil, rootlet development is
favored very likely as a way to increase water and nutrient uptake. An increase in the
latter two physiological functions is generally linked to higher leaf area, plant fresh
weight and seedling survival.
After the first growing season, seed rates did not affect significantly: 1) the growth
(leaf area, root and shoot fresh and dry weights), 2) the morphology of wood-cultivated
American ginseng (Tables 3, 4 and
5) or 3) the incidence of
Plant spacing effects may eventually show up later during plant development (up to 3-4
years). For field-cultivated American ginseng, Konsler and Shelton (1984) have observed a
strong influence of plant spacing (29 to 258 plants m2) on root growth during the 6 years
of the study. Average root size was proportional to the space available per plant, while
root yield per unit area was closely related to plant population. They reported the
increased probability of disease epidemics and alleopathic reaction with increasing plant
Results from this study have shown that woodland
soil preparation by tillage or cultivated beds improved the establishment and growth of
wood-cultivated American ginseng after the first growing season, due to better root
development for water and nutrient uptake. However, no significant difference was observed
between soil tillage and beds cultivation. In general, mulch wood chips favored plant
emergence and survival. It is too early to report on any effect of plant spacing on
growth, root quality, and incidence of diseases of wood cultivated ginseng. In order to
better know the long term effects of soil preparation, plant spacing and mulch treatments
on American ginseng root growth and quality, further observations and analysis will be
done in the next 4 years.
J.M., A.H. Der Morderosian
and T.M. Lee. 1984 Continuing studies on the ginsenoside content of commercial ginseng
products by TLC and HPLC. II. Proc. 6th North American Ginseng
Conference, Guelph, ON,
||Carlson A.W. 1986. Ginseng:
America's botanical drug connection to the orient. Econ. Bot. 40:233-249.
||Charron D., D. Gagnon. 1991. The
demography of northern populations of Panax quinquefolium (American ginseng). J. Ecology
||Kim, D.C., S.M. Chang et J.
1995. Effects of the chemical properties of field soils on the contents of sugars and
saponin in ginseng roots. Agr. Chem. biotechnol. 38(1): 72-77.
||Konsler T.R. 1986. Effect of
stratification temperature and time on rest fulfilment and growth in American ginseng. J.
Am. Soc. Hortic. Sci. 111:651-654.
||Konsler T.R. 1982. Some responses
of American ginseng (Panax quinquefolium L.) to kind of bed mulch and to plant spacing
thru four growing season. Proceeding of the fourth national ginseng
USA Eds C.R. Roberts and J English.
||Konsler T.R. and J.E.
1984. Plant spacing, mulches and soil effects on cultivated American ginseng (Panax
quinquefolium L.). Sixth North American ginseng conference, University of Guelph, Canada,
Eds J.T.A. Proctor.
||Konsler T.R., S.W.
Shelton and E.J. Staba. 1990. Lime and phosphorus effects on American
ginseng:II. Root and
leaf ginsenoside content and their relationship. J. Amer. Soc.
Hort. Sci. 115:575-580.
||Lee J.C., SK
Cheon, Y.T. Kim and
J.S. Jo .1980. Studies on the effect of shading materials on
temperature, light intensity,
photosynthesis and root growth of Korean ginseng (Panax ginseng C.A. Meyer). Korean Soc.
Crop Sci. 25:91-98.
||Lewis W.H.and V.E.
Population dynamics of the American ginseng, Panax quinquefolium
(Araliaceae) Am. J. Bot.
Y.C., J. Zhu, L. Benkrima, L.
Sun, S. Sain, C. Kont, and Y.Y. Plaut-Carcasson. 1994. A comparative study on ginsenosides
in different commercial ginseng products and tissue culture samples using
International Ginseng Conference Proceeding, Vancouver, Canada. Eds W.G.
Whitehead, J.T.A. Proctor and JT Kyle.
||Oliver, A. 1996. Ginseng
Production Guide for commercial growers. 1996 ed., British Columbia: Ministère de
l'Agriculture, des pêcheries et de l'Alimentation.
||Persons,1 W.S. American ginseng
farming in its native woodland habitat. 1994. In The challenges of the 21st century in
Vancouver, edited by W.G. Bailey, C. Whitehead, J.T.A. Proctor, and J.T.
Fraser University, B.C., 78-83.
||Persons,2 W.S. 1994. American
ginseng: green gold. Revised ed., Asheville, North Carolina: Bright Mountain Books,
||Proctor J.T.A. and W.G.
1987. Ginseng: Industry, botany and culture. Hort. Reviews 9:187-236.
||Proctor J.T.A. and M.J.
1986. Air and root-zone temperature effects on the growth and yield of American ginseng.
J. Hortic. Sci. 61:129-134.
||Stathers R.J. and W.G.
1986. Energy receipt and partitioning in a ginseng shade canopy and mulch
Agricultural and Forest Meteorology 37:1-14.
B.M., J.M. Follett,
M.H. Douglas, J.A. Douglas and G.A. Parmenter. 1995. Production of Panax spp in New
Zealand. Acta Hort. 390:83-89.
||Wang H., J. Fan, X. Yang, G. Fan,
Q. Liou and H. Dai. 1994. A study on ginseng cultivation under forest conditions and its
physiological and ecological characteristics. International Ginseng Conference
Vancouver, Canada. Eds W.G. Bailey, C. Whitehead, J.T.A. Proctor and JT