J. Trop. Agric. and Fd. Sc.

36(2)(2008):
S.L. 000–
Tan, M.000
Muhammad Ghawas, M.Y. Mohamad Najib and M. Zawayi

Preliminary evaluation and selection of stevia under

Malaysian conditions
(Penilaian dan pemilihan awal aksesi stevia dalam keadaan Malaysia)

S.L. Tan*, M. Muhammad Ghawas*, M.Y. Mohamad Najib** and M. Zawayi*

Key words: stevia, accessions, field evaluation, leaf yield, ratooning

Abstract
Accessions of stevia (Stevia rebaudiana Bertoni) were introduced from Russia,
Paraguay, Canada, USA and Japan. After vegetative propagation, they were
field planted for observations on their leaf yield over 11 harvests in the period
of one year. Of the 67 accessions, six with high rates of success in vegetative
propagation (thus, yielding more plants) were selected. All of these originated
from Canada, except for one from Russia. The selected accessions were evaluated
in two field trials, over seven and six harvests. The highest yielding accessions
were MSR 028, MR 012 and MR 007. MSR 028 topped 10 t/ha in cumulative
fresh leaf yields, which is equivalent to 2.8 t/ha dry leaf yield and similar to
what has been reported in Canada where stevia is planted as an annual. Thus,
ratooning may be able to overcome the problem of early harvests (after 1 month)
necessitated by the short daylength conditions in Malaysia.

Introduction sugarcane cultivation, and the country has

Stevia (Stevia rebaudiana Bertoni) is a been largely dependent on sugar imports to
herbaceous plant originating from Paraguay. satisfy local demand. Malaysians are known
The plant, especially the leaves, produces for their ‘sweet tooth’, consuming a lot of
diterpene glycosides, primarily stevioside sugar not only in their drinks and beverages
and rebaudioside, which have a sweetening but also in their snacks, such as traditional
effect reportedly 40–250 times sweeter than cakes. This unhealthy habit may be partially
sucrose (Brandle 2004). For this reason, responsible for the alarming rise in diabetic
interest in this plant has picked up in recent cases – from 0.65% of the population in
years because of its potential as a 1960 to 16–18% in 1998 (Mustaffa 1998).
non-calorific natural sweetener – a boon to Apart from a doctoral thesis in 1990
the health food industry, particularly targeted (Wong 1990), very little research has been
to individuals with an obesity problem as carried out on stevia in the country. With
well as diabetics. the resurgence of interest, in 2004, several
Interest in this plant has also arisen in introductions were made from various
Malaysia as a result of the sugar shortage sources which were subsequently evaluated
not too long ago. Except in the extreme under local conditions. This paper reports
northern part of the Peninsula, the generally preliminary results of these evaluations,
wet climate of Malaysia does not favour
*Rice and Industrial Crops Research Centre, MARDI Headquarters, Serdang, P.O. Box 12301, 50774 Kuala Lumpur,
Malaysia
**MARDI Bukit Raya, P.O. Box 1, Pendang Post Office, 06707 Pendang, Kedah, Malaysia
Authors’ full names: Tan Swee Lian, Muhammad Ghawas Maarof, Mohamad Najib Mohd Yusof and Zawayi Mat
E-mail: sltan@mardi.gov.my
© Malaysian Agricultural Research and Development Institute 2008


Evaluation and selection of stevia

culminating with the shortlisting of a Table 1. Frequency of fertilizer applications

number of promising accessions. and rates in the evaluation trials on
stevia accessions
Materials and Methods Ratoon Months after Fertilizer rate (t/ha)
Single plot observations field planting Organic NPK
Through a collaborative project with a
private company, Stevian Biotechnology 1st   3.0 0.5 –
Corporation Sdn. Bhd., accessions of stevia 2nd   4.5 – –
3rd   6.0 0.5 0.5
were introduced from Russia, Paraguay,
4th   7.5 – –
Canada, USA and Japan. The accessions 5th   9.0 0.5 –
were multiplied vegetatively through 6th 10.5 – –
cuttings in a greenhouse used as the nursery. 7th 12.0 1.0 1.0
When they reached a height of 5 cm,
the plants were transferred to the field at
MARDI Headquarters Station, Serdang.
In the field, the various accessions
including one originally studied by Wong
(1990), were planted in 1.2 m wide ridges,
spaced 24 cm apart, with a plant spacing
of 20 cm. Basal fertilizer using organic
fertilizer (processed chicken dung) at 1 t/ha
was applied between ploughing and building
the beds. After the first ratoon, 0.5 t/ha of
organic fertilizer was applied. The next
fertilizer application was after the third
ratoon, using 0.5 t/ha of organic fertilizer Plate 1. Early flowering in the field due to local
short-day conditions
and 0.5 t/ha of a compound NPK fertilizer
(10:10:10), and thereafter after every 1½ Selection of promising accessions were
months as in Table 1. The fertilizers were based on two criteria:
applied between the plant rows (Muhammad • Group A comprised accessions which
Ghawas et al. 2007). Manual weeding was had a high rate of success in vegetative
carried out twice per month. propagation, yielding more plants.
Owing to early bud emergence under • Group B comprised accessions which
the short daylength conditions in Malaysia had a high computed cumulative yield
(Plate 1), the plants were harvested at one per hectare.
month after field-planting in July 2005.
Harvesting was carried out by cutting Replicated trials
back the plants at about 8–10 cm from the All the replicated trials adopted the same
soil surface. Thereafter, the plants were agronomic and cultural practices as before.
harvested approximately every month
over a period of one year from the time of Trial 1  The six accessions in Group
field-planting (until May 2006), totalling A were evaluated in a replicated trial
11 harvests. Owing to the variable numbers (following a Randomized Complete Block
of plants from each accession, the final Design or RCBD) over seven harvests
cumulative yield (in t/ha) of each accession from November 2005 to July 2006. Two
was calculated based on a population of checks were included in the trial, namely
166,667 plants/ha. MSR 031 (an accession of Russian origin
with moderate yield, of interest to Stevian
Biotechnology Corporation Sdn. Bhd.)


 S.L. Tan, M. Muhammad Ghawas, M.Y. Mohamad Najib and M. Zawayi

and MSR 069, the ‘Malaysian’ accession. plants propagated from each accession
Sample size per plot in each of the three ranged from 2 to 87.
replications was 30 plants. There was an increasing trend in yield
over the 11 harvests as shown by the yields
Trial 2  The above trial was duplicated per harvest, averaged over the 67 accessions
with the six accessions in Group A in a (Figure 1). There appears to be a dip in
replicated trial (RCBD) over six harvests yields at the sixth and ninth harvests.
from February to July 2006. No check
variety was used in Trial 2. Every plot in
each of the four replications accommodated
45 sample plants as well as border rows.
Trial 2 was conducted to confirm the yield
performance of the accessions over a
different growing period.

Results and discussion

General botanical description
Stevia is a perennial herbaceous plant,
with simple, opposite leaves with rather
short petioles (Plate 2). Leaf shape can
range from oblanceolate (MSR 007) to
ovate (MSR 012) to spatulate (MSR 028)
(Plate 3). The leaf margin is generally
dentate although may be scalloped as in
MR 028.
The plants are determinate, i.e. will
stop growing once they bloom as the flowers
are borne at the tips of the branches or
stems. Flower heads consist of five white Plate 2. Stevia rebaudiana plant
florets each.

Single plot observations

A total of 68 accessions resulted from
the seed batches introduced as well as
one ‘Malaysian’ accession, left over from
the research carried out by Wong (1990)
(Table 2). Two of the total of 69 accessions
failed to be propagated and were dropped Plate 3. The three promising stevia accessions,
from the field evaluation. The number of MSR 007, MSR 012 and MSR 028

Table 2. Number of stevia accessions derived from seeds of different origins

Accession No. of seedling Surviving Country

numbers accessions accessions of origin
MSR 001–MSR 028 28 27 Canada
MSR 029–MSR 054 26 25 Russia
MSR 055–MSR 057   3   3 Paraguay
MSR 058–MSR 060   3   3 USA
MSR 061–MSR 068   8   8 Japan
MSR 069  1  1 ‘Malaysia’


Evaluation and selection of stevia

Data from those accessions with the yields of these six accessions over the
most number of plants (Group A) as well seven harvests in Trial 1 are presented in
as those with the highest extrapolated Figure 2. There was a peak in yields at
yields from the 11 harvests over a period the sixth harvest, followed by a decline at
of one year (Group B) are presented in the seventh harvest. This peaking in yield
Table 3. In Group A, accessions MSR 012 did not seem to be associated with the
and MSR 029 were higher yielding than monthly rainfall pattern. All six accessions
the check, MSR 069 (67.4 t/ha). Except for produced cumulative yields not significantly
MSR 029 which came from Russia, these different from the two checks, MSR 031
accessions originated from Canada. All the and MSR 069. The highest cumulative yield
nine accessions in Group B outyielded MSR obtained by accession MSR 007 at 10.4 t/ha
069 by 223–300%, i.e. about 2¼ to 3 times. was 56% and 78% higher than MSR 031
The countries of origin of these accessions and MSR 069, respectively. This is followed
were Canada, Russia and USA. closely by MSR 028 at 10.3 t/ha (Table 4).
In Trial 2, the trend in increasing yields
Replicated trials followed by yield decline was repeated
The six accessions in Group A were (Figure. 3), with the peak at the fifth harvest
observed to have wider leaves. Mean rather than the sixth. Again, the peak was
not associated directly with the rainfall
1,200 pattern. The best performing accession after
Mean yield (g/harvest)

◆
1,000 ◆ ◆
◆
◆ ◆
◆
◆
six harvests was MSR 028 at 10.8 t/ha, a
800
◆
◆ yield which was significantly higher than
600 ◆ all the other accessions except MSR 012
400 (Table 4).
200
Based on the results from Trials 1
0
1 2 3 4 5 6 7 8 9 10 11 and 2, it may be concluded that the most
Harvest number promising accessions in Group A are MSR
Figure 1. Yield trend (averaged over 67 028, MR 012 and MR 007 (Plate 3). It
accessions) of stevia over 11 harvests in one year

Rainfall ◆ MSR 007 ● MSR 012 ■ MSR 023 ▲ MSR 024

6.00 ■ MSR 028 ▲ MSR 029 MSR 031 ◆ M 069 500.0

450.0
5.00 ◆
400.0
●

■ 350.0
Monthly rainfall (mm)

4.00
300.0
Yield (t/ha)

3.00 ● 250.0
◆
▲

200.0
2.00 ▲
150.0
◆
■
◆ ■
◆
◆ ▲
■
▲ 100.0
1.00 ▲
■
●
■
●
● ■ ●
●

●
▲
◆
■
●
●
▲
◆
●
▲
◆
▲ 50.0
■ ▲ ■ ◆
◆
■ ▲ ●
▲
◆ ■
◆ ● ■
◆ ■
▲
0.00
▲
●
0.0
1 2 3 4 5 6 7
Harvest number
Figure 2. Yield trends of six selected stevia accessions compared to two checks
(MSR 031 and MSR 069) over seven harvests in Trial 1


 Table 3. Stevia accessions which are promising in terms of number of plants or cumulative yields compared with the check MSR 069

Accession Origin Plants/ Harvest number Total Cumulative

plot (g) yield (t/ha)
1 2 3 4 5 6 7 8 9 10 11
Group A
MSR 007 Canada 87 2500 3800 3380 2800 * 3000 5620 4620 2170 3410 3720 35020 67.22
MSR 012 Canada 76 2760 2910 2020 4120 * 4550 4940 4940 3100 5560 3920 38820 85.30
MSR 023 Canada 66 1910 2050 1980 2060 3500 2100 1700 1700 1800 1650 1780 22230 56.25
MSR 024 Canada 63 1100 1600 * 1760 2670 2050 2350 2350 2400 2550 2660 21490 56.97
MSR 028 Canada 79 1950 2200 3400 3380 4700 2150 1680 1680 2000 2850 3560 29550 62.47
MSR 029 Russia 79 2200 6200 5200 5500 5300 5600 2960 2960 2490 1750 1520 41680 88.11
Group B
MSR 005 Canada 5 280 400 420 320 320 320 380 380 310 760 1000 4890 163.33
MSR 013 Canada 18 800 800 1720 2780 2260 1440 1550 1550 1400 1580 1520 17400 161.43
MSR 017 Canada 17 400 450 1300 2380 2340 1360 1760 1760 1750 800 3400 17700 173.88
MSR 025 Canada 18 900 1020 1700 1880 1460 1600 2280 2280 2200 2100 1800 19220 178.32
MSR 050 Russia 14 510 970 1540 1500 1500 1150 1240 1240 1150 1700 1100 13600 162.23
MSR 051 Russia 14 500 930 1520 1300 1680 1200 1260 1260 1200 1100 680 12630 150.66
MSR 058 USA 15 460 980 1700 1400 1280 800 2000 2000 1690 1480 720 14510 161.54
MSR 059 USA 10 220 480 1520 890 900 790 1600 1600 720 1280 660 10660 178.02
MSR 060 USA 14 600 850 1100 1100 1300 600 2400 3000 1760 2220 2020 16950 202.19
MSR 069 ‘Malaysia’ 58 2500 2850 * * * 1650 2700 2700 3660 4500 2860 23420 67.43
*No harvest because plant growth too little


S.L. Tan, M. Muhammad Ghawas, M.Y. Mohamad Najib and M. Zawayi
Evaluation and selection of stevia

is also interesting to note that at the peak to dry, this is equivalent to a fresh yield
harvest, the yield was almost half the of 7.88 t/ha. The practice in Canada is to
cumulative yield after sixth or seventh handle the crop as an annual and completely
harvests. This may have implications on harvest it in one go when the plants reach
the decision of whether or not to continue about 40–60 cm tall after about 4 months.
maintaining and harvesting the ratoon crops This is followed by replanting. However,
past the peak yields. in Malaysia because of short daylength
It has been estimated in Canada that conditions, the plants have to be harvested
a dry yield of 2.2 t/ha of dried leaves much earlier before they flower, i.e. at about
is necessary to make stevia cultivation one month after field-planting. However,
profitable (Columbus 1997). With a by managing stevia as a ratooning crop,
conversion rate of roughly 28% from fresh the data from our trials show that yields
exceeding the break-even yield set by
Table 4. Cumulative yields over 7 and 6 harvests Canada were achieved after 6 –7 months.
of selected stevia accessions in Group A Using the above-mentioned conversion
rate, 10 t/ha fresh yield is equivalent to
Accession Cumulative Peak yield
yield (t/ha) (t/ha)
2.8 t/ha dry yield. This is higher than the
yields reported in China (1.3–1.4 t/ha),
At 6th harvest
equivalent to Canadian yields (2.85 t/ha), but
MSR 007 10.44a 5.00
lower than yields in USA (3.6 t/ha), Russia
MSR 028 10.33ab 4.26
MSR 012   8.60ab 4.63 (1.4–5.5 t/ha) and India (4 t/ha) (Midmore
MSR 029   6.81ab 2.70 and Rank 2002). In order to improve stevia
MSR 031 (Check 1)   6.71ab 2.96 yields in Malaysia, it is obviously necessary
MSR 024   5.80ab 2.04 to select for less photosensitive genotypes to
MSR 023   5.42b 1.41 ensure that the plants do not flower so early
MSR 069 (Check 2)   5.85ab 2.81 which necessitates an equally early harvest,
At 5th harvest leaving insufficient time for the crop to
MSR 028 10.76a 4.26 develop more biomass.
MSR 012   7.07ab 3.42 It will also be necessary to study the
MSR 024   5.41b 2.21 performance of the nine accessions in Group
MSR 007   5.15b 2.13 B which show high yield potential but
MSR 029   4.52b 2.14
were marred by their lower success rate in
MSR 023   3.84b 1.37
vegetative propagation. With the improving
Values with the same letter are not significantly techniques in vegetative propagation since
different (p <0.05)

Rainfall ◆ MSR 007 ● MSR 012 ◆ MSR 023

4.50 ■ MSR 024 ▲ MSR 028 ● MSR 029 450.0
▲
4.00 400.0
3.50 350.0
Monthly rainfall (mm)

3.00 300.0
Yield (t/ha)

2.50 250.0
◆
2.00 200.0
■
1.50 ▲
●
◆
150.0
●
1.00 ▲
◆
■
◆
●
▲ 100.0
◆
● ■
0.50 ▲
●
■
●
●
■
◆
◆
●
■
● ◆ 50.0
●
◆
◆ ◆ ●
0.00 00.0
1 2 3 4 5 6
Harvest number
Figure 3. Yield trends of six selected stevia accessions over six harvests in Trial 2


 S.L. Tan, M. Muhammad Ghawas, M.Y. Mohamad Najib and M. Zawayi

the time of their introductions, this problem Midmore, D.J. and Rank, A.H. (2002). A new
with multiplication rate may be overcome. rural industry – Stevia – to replace imported
chemical sweeteners. A report for the Rural
Industries Research and Development
Acknowledgement Corporation. RIRDC Web Publication No
Rainfall data were kindly provided by the W02/022, 50 p. RIRDC Project No UCQ-16A
Climatological & Hydrological Division of Muhammad Ghawas, M., Zawayi, M., Mansor,
the Malaysian Meteorological Department. P. and Muhamad Azhar, A.B. (2007).
Penanaman dan pengeluaran tanaman stevia.
References Bul. Teknol. Tanaman, MARDI (accepted for
Brandle, J. (2004). FAQ – Stevia, Nature’s Natural publication)
Low Calorie Sweetener. Agriculture and Agri- Mustaffa, B.E. (1998). Diabetes Epidemic in
Food Canada. Retrieved on Sept. 2007 from Malaysia Website of the Malaysian Medical
http://sci.agr.ca/london/faq/stevia_e.htm Association. Retrieved on ?????? from http://
Columbus, M. (1997). The cultivation of stevia, mma.org.my/mjm/3_diabetes_04.htm
“Nature’s Sweetener”. Ontario Ministry of Wong, L.J. (1990). Genetic studies of stevioside
Agriculture and Food (OMAF) Herb Series. content and agronomic characters and their
Retrieved on Sept. 2007 from http://www. responses to cloning in Stevia rebaudiana
omaf.gov.on.ca english/crops/facts/stevia.htm Bert. PhD thesis, 102 p. Faculty of
Agriculture, Universiti Pertanian Malaysia

Abstrak
Aksesi stevia (Stevia rebaudiana Bertoni) telah dibawa masuk dari Rusia,
Paraguay, Kanada, Amerika Syarikat dan Jepun. Selepas pembiakan tampang,
aksesi tersebut ditanam di ladang untuk pemerhatian hasil daun selama 11
penuai dalam tempoh setahun. Antara 67 aksesi, enam yang menunjukkan
kadar pembiakan tampang yang tinggi (dengan menghasilkan lebih anak pokok)
dipilih. Semuanya berasal dari Kanada, kecuali satu aksesi dari Rusia. Aksesi
terpilih dinilai dalam dua uji kaji ladang masing-masing selama tujuh dan enam
penuaian. Aksesi yang paling berpotensi dari segi hasil terdiri daripada MSR 028,
MR 012 dan MR 007. MSR 028 dapat melebihi hasil segar kumulatif sebanyak
10 t/ha dalam kedua-dua uji kaji. Hasil ini bersamaan dengan 2.8 t/ha hasil daun
kering dan tidak berbeza daripada apa yang dilaporkan di Kanada apabila stevia
ditanam sebagai tanaman semusim. Ini bermakna, melalui cara ratun, mungkin
masalah menuai awal (selepas satu bulan) yang terpaksa dilakukan kerana
keadaan tempoh siang yang pendek di Malaysia dapat diatasi.

Accepted for publication on 3 July 2008