SAGO PALM 27: 1−8 (2019)

Wind-resistant characteristics of native and Indonesian tissue-cultured
sago palms (Metroxylon sagu rottb.) in Leyte, philippines
Masanori Okazaki1,*, Mitsuhisa Baba2, Toshihiko Momose3, Shun Nishiyama4,
Nadirman Haska5, Marcelo A. Quevedo6, Ma. Kristine L. Aban6 and Suzette B. Lina7
1

2

3

Japan Soil Research Institute, Inc., Nishitokyo, Tokyo 188-0001, Japan

Department of Veterinary Science, Kitasato University, Towada, Aomori 034-8628, Japan

Department of Environmental Sciences, Ishikawa Prefectural University, Nonoichi, Ishikawa 921-8836, Japan
4

Ishikawa Agricultural Experimental Station, No-1-1, Mizuho, Noto, Houzu, Ishikawa 927-0311, Japan

5

Biotech Center of the Agency for the Assessment and Application of Technology, Jakarta, Indonesia
67Philippine Rootcrops Research and Training Center (PhilRootcrops),
Visayas State University, Leyte, Philippines

Department of Soil Science, Visayas State University, Leyte, Philippines* Corresponding author

Abstract: Native sago palms were transplanted from Dulag to a Pangasugan experimental field, Leyte,
Philippines in 2005 and tissue-cultured sago palms from Indonesia were transplanted to Pangasugan in 2007.
The growth of native Dulag Philippines (NDP) and Indonesian tissue-cultured (ITC) sago palms was evaluatedusing the growth rate for palm height and number of leaves. The tissue-cultured sago palms (2.13 m/year) had ahigher growth rate than that of the native sago palm (1.38 m/year) until 2012. The recovery of ITC sago palm
(1.48 m/year) after wind damage by Typhoon Yolanda (maximum wind velocity: 65 m/s) in 2013 was slower
than that of NDP (2.14 m/year) from 2014 to 2016. The development of living leaves of both NDP and ITC sago
palms increased from 2 to 16 before Typhoon Yolanda hitting. Typhoon Yolanda teared off leaves, resulting in 2
for NDP and 4 for ITC. Until 2016 thirteen living leaves were observed for both NDP and ITC. The bending
moment (Mb) at the height of palm trunk breaking by Typhoon Yolanda varied from 141 to 342 kNm for NDP
sago palms and from 37.7 to 183 kNm for ITC sago palms. These Mb values show the strong wind resistantproperties of sago palms. Both NDP and ITC sago palms, after being hit by Typhoon Yolanda werecharacterized by quick regrowth from the growing point of the trunk. We can conclude that the strong windresistant characteristics of sago palms lend considerable support to their survival in typhoon-prone areas of thePhilippines.
Keywords: bending moment, Indonesia, native, Philippines, tissue-cultured

Introduction

Okazaki and Kimura (2015) showed the areas andnumbers of typhoons in the Pacific Ocean from 1970

to 1997. Seventy-seven typhoons occurred within thesago growing areas 35 ° north latitude from theequator and 100 to 190 ° east longitude. Six to nine

typhoons out of twenty typhoons in the Philippine

territory and territorial waters directly affect thePhilippines, and five of these storms are destructive(InterRisk Asia, 2017; Asian Disaster Reduction

Center, 2019). Strong winds from October toDecember have caused serious damage to theeconomy and people of the Philippines.

A standing plant must have a strong trunk and rootsystem to withstand wind damage, such as breakage

and other injuries. Fujita (2014) insisted that tree

M. Okazaki et al.

2

forms are an important factor in withstanding strong

Pangasugan, Leyte in November 8, 2013 (Ministry ofcurving and so on. Uprooting and trunk breaking arebiomass production. Sago-growing countries havewind. Severe plant damage from strong wind takes theform of uprooting, trunk breaking, inclination,

important damages from the viewpoint of occurrence
frequency and influence (Suzuki, 2012). Uprooting

occurs when the base foundation for the root system isdefeated, in the decreasing effect order of bending
strength of trunk > bending stress and bending

moment produced by wind load > resistance of rootsystem. On the other hand, trunk breaking is observedwith the failure of trunk bending moment against

wind load, in the decreasing effect order of resistanceof root system > bending stress and bending moment

produced by wind load > bending strength of trunk(Suzuki, 2012).

The bending moment of the trunk (Mb) is
introduced by the equation
Mb = 1/2 ρ CdAV 2H

where Mb is the bending moment (kg m /s ), ρ is the air
22

density (kg/m ), Cd is the drag coefficient (0.3 to 0.6 for3tree species), A is the lateral cross section of the tree

crown (m2), V is the wind velocity (m/s), and H is theheight from the ground to the wind center (m).

Drag is a crucial factor in determining the forces ona tree in high wind (Vogel, 1989). The dragcoefficient (Cd) indicates the conversion percentagesof wind energy to wind load (Mayhead, 1973). The

bending moment (James, 2010) of palms determines
the wind resistance of trunks and leaves. Until 2015,

the maximum wind velocity in building standards was
30 to 46 m/s (Information Center for Building

Administration, 2015) in Japan. However, muchhigher maximum wind velocities have been observedin Japan recently, for example, 85.3 m/s in Miyako

Island, Okinawa (Japan Meteorological Agency,2019). Accordingly serious damage by much higher
maximum wind velocities should be estimated.

Typhoon Yolanda (Haiyan) (895 hPa in the center, 65

m/s maximum wind velocity, 90m/s maximum
instantaneous wind velocity), one of the strongest

tropical typhoons, directly hit the sago field in

Land, Infrastructure, Transport and Tourism, 2014).

Tissue culture technology will change sago

tried to introduce tissue culture to sago seedlings bysomatic embryogenesis (Alang and Krishnapillay,

1987; Hisajima et al., 1991; Tahardi et al., 2002;
Ogita and Yamaguchi, 2003, Sumaryono et al., 2009;
Novero et al., 2010; Sumaryono et al., 2012; Ibrahim

et al., 2014). In 2007 eight tissue-cultured sago
seedlings in the Biotech Center of the Agency for theAssessment and Application of Technology,
Indonesia were transplanted in Pangasugan (Okazaki

et al., 2012; Nishiyama et al., 2014) to elucidate

whether Indonesian tissue-cultured (ITC) sago

seedlings were able to grow in a different
environment. The mean height of eight palm seedlings
was around 30 cm at transplanting time. The growing
speed and strength of tissue-cultured sago palms

should be compared to those of native Dulag

Philippines (NDP) sago palms in Leyte, because there
is no data on the growth of ITC sago palms underfield conditions.

The growing points and leaves of 8-year-old nativeand 6 year-old tissue-cultured sago palms weredamaged and partially separated from the apical partsof the palms by Typhoon Yolanda (Nishiyama et al.,2014; Nishiyama et al., 2015). The damaged apicalpart of the sago palms had recovered gradually(Nishiyama et al. 2018).

The objectives of this study are to show the wind-

resistant property of native (NDP) and Indonesiantissue-cultured (ITC) sago palms in Leyte, Philippines

and to evaluate the successful regrowth of sago palms
in typhoon-prone areas of the Philippines.
Materials and Methods

1. Native and Indonesian tissue-cultured sago palms
Native (NDP) sago palm seedlings were collectedfrom Dulag, Leyte, Philippines in 2005 and transplanted

to Pangasugan. The tissue-cultured (ITC) sago seedlings

were transported from the Biotech Center of the Agency

Wind-resistant characteristics of native and Indonesian tissue-cultured sago palms (Metroxylon sagu Rottb.) in Leyte, Philippines

3

for the Assessment and Application of Technology,

3. Palm height and number of leaves

pretreatment after washing suckers. The explants were

the petiole. The palm height was measured and the

Jakarta, Indonesia to Pangasugan in 2007. The explants

The sago palm growth rate is regulated by thewere provided by means of sanitization andnumber of developing leaves per year and the size of(soil, compost and fertilizers) and incubated in an air-

growth stage. Gradually, however, longer intervals

planted in polyethylene buckets containing a medium
conditioned greenhouse for 6 to 8 weeks until two

leaves developed, and adapted to the environment until
development of the fourth leaf. The explants weregrown to a seedling weight of 500 g. Then they weretransported by air to the Philippines and acclimated for

5 days and transplanted to the sago field at Pangasugan.
At the time of transplanting in the field, the sago
seedlings had a fourth leaf.

2. Experimental field and plots

The sago experimental field was located in a 0.4 ha

lowland area of Pangasugan, Leyte, Philippines. The

area is in an Af climate (Köppen climate classification)with over 2200 mm of precipitation/year. The soil has

leaves counted at the short interval during the early

were used. The height of the sago palms and the trunk

diameter at breast height were measured using ameasuring pole (Senshin Kogyo 10m), a measuring

tape (Sekisui Jushi Eslon 12-50HRW 50m) and adigital clinometer (Haglof ECIID), and the number ofleaves was counted with the naked eye. These threefactors are closely related to the growth of trees(Editorial Board of Forest Ecology and Conservation,2010).

4. Bending moment of the sago palm

According to the proposal (Shi-igai, 1993;

Ishikawa, 2005; Suzuki, 2012), the bending

moment (Mb) of the sago palm was calculated,a silt loam texture (Lina et al., 2009), a slightly acidic

based on the wind-receiving area (lateral cross(Table 1). Twelve NDP sago seedlings from Dulag, inand palm height from the living leaf at the lowest

pH of 6.3 to 6.5, and electrical conductivity of 46 to

51 μ S/cm and 1.97 ± 0.40 to 2.13 ± 0.50 gN/kg

section) of sago palms which was calculated by the

product of living leaf length at the lowest position

Table 1. Chemical properties of soils (control) in Pangasugan, Leyte, Philippines

position, and thecenter of windblowingwaspresent at the trunk

breaking point. The
bending moment isintroduced
the eastern part of Leyte were transplanted to

Mb = 1/2ρ CdAVmax2Hb

andevaluated by theequation

Pangasugan in 2005 in a 4m x 2m plot trial without

where Mb is the bending moment (kg m2/s2), ρ is thepalms were produced for use in starch production. In

palms which was calculated by the product of living

fertilization; two 4m x 2m plots were combined toform one 4m x 4m plot in 2007; and finally, three
2007, eight ITC seedlings with the fourth leaf wereplanted in a 4m x 4m plot without fertilization.

Suckers were controlled to make one mother palm andone sucker per plot.

air density (kg/m3), Cd is the drag coefficient (0.3), A is

the wind-receiving area (lateral cross section) of sago
leaf length at the lowest position and palm height fromthe living leaf at the lowest position (m2), Vmax is the

maximum wind velocity (65 m/s for Typhoon
Yolanda), and Hb is the height from the ground to theM. Okazaki et al.

4
point of the wind center (m) .
Results

1. Palm height

The three NDP and six ITC sago palms determined

in Pangasugan (two ITC sago palm seedlings died
before being hit by Typhoon Yolanda) are shown in   '$:/22#)/31
   8:.(760   '$:0/2#)/303   8:.(726   '$:0.4#)311
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   8:.(770

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cultured (ITC) and native (NDP) sago palms ranged









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+&0..5)0.//'!)!!*
+&0./2)0./4








Fig 1. Mean height of native (NDP) and Indonesiantissue-cultured (ITC)sago palms

from 2 to 16 living leaves during this field experiment(Fig. 3). The number of living leaves of NDP sago
Yolanda   "*  + 

18



 

Pangasugan, Leyte, Philippines (April of 2014)

The development of living leaves of both tissue- 0246/.

     





0..30..50..70.//0./10./3

palms was 844 ± 202 cm and 837 ± 105 cm in 2011

 

 


 

i 


Fig  2. Sagopalms damaged by Typhoon Yolanda in

2. Number of living leavesand 1050 ± 280 cm and 781 ± 90 cm in 2016,
respectively. The growth rate of ITC sago palms washigher than that of NDP sago palms. ITC sago palms

Numberoflivinggleaves







Fig. 1. The mean height of the NDP and ITC sago

(206 cm/year; C in Fig.1) had a higher growth rate  Nfrom 2007 to 2011 than NDP sago palms (143cm/year; A in Fig.1) did from 2005 to 2012. Typhoon
Yolanda hit sago palms on November 8, 2013. The

recovery rate of ITC sago palms (148 cm/year; D in

16
14
12
10
8
6
4
2
0
2004

 

 

2006

2008




Native (NDP)
Native(NDP)

 



2010



2012



2014



Indonesian tissue cultured (ITC)
IndonesiantissueͲcultured(ITC)

 





Fig 3. Number of living leaves of native andtissue-cultured sago palms
2016 








Fig. 1) after wind damage was slower than that ofpalms reached a maximum 5 years after transplanting.

height of ITC sago palms measured in 2012 comparedbecause living leaves were blown by Typhoon

NDP sago palms (214 cm/year; B in Fig. 1) from2014 to 2016. The reason of decrease in the mean

to those measured in 2011 is unknown. Figure 2
shows the damaged sago palms in the Pangasugan

experimental field in April 2014. The growth point ofsago palms was still alive. However, the living leaves
were blown over by the strong wind.

In case of ITC sago palms, unfortunately there is norecord on the maximum number of living leaves,
Yolanda.

3. Wind-resistant characteristics of the sago palm

Table 2 shows the lateral cross section of sago

palms (m 2), height from the ground to the trunk
breaking point (m), diameter at breast height (cm),and bending moment at Vmax (kNm). The lateralWind-resistant characteristics of native and Indonesian tissue-cultured sago palms (Metroxylon sagu Rottb.) in Leyte, Philippines

5g moment
g palms
y windTable 2. Bending
moment ofof thethe ssago
palms bywind load
load

CrossCross
on area Height (Hb) fromof palm crownground to trunkm2
breaking point m
Na ve
(NDP)

Indonesian
TissueCultured
(ITC)

5.7
6.2
2.9
47
4.7
6.1
4.2
37
3.7
4.8
4.8

79.5
58.3
64.3
10 7
10.7
39.5
32.9
33 5
33.5
47.1
31.2

Diameter Bending momentat breast(Mb) at Vmax
height cm
kNm
342
275
141
37 7
37.7
183
105
93.2
93 2
171
113

41
40
38
35
32
35
31
33
34

N = kg m/s2
Bending moment of sago palm by wind load (Mb: kgm2/s2) = ½ ρ Cd A Vmax2 Hb
ρ = 1.2
1 2 kg/m
k / 3
Cd = 0.3
on area m2
A = crossVmax = wind velocity 65 m/s
Hb = height from ground to broken point mcross section of three NDP and six ITC sago palm

influence on the growth of tissue-cultured sago palms

from the trunk breaking point was 2.9 to 6.2 m forform, above-ground and root balance and trunk quality

crowns varied from 58.3 to 79.5 m and from 10.7 to2

47.1 m2, respectively. The wind center point estimated
NDP sago palms and 3.7 to 6.1 m for ITC sago palms.
The diameter at breast height ranged from 38 to 41 cm
for NDP sago palms and from 31 to 35 cm for ITC

sago palms. The bending moment at Vmax ranged

from 141 to 342 kNm for NDP sago palms and 37.7 to
183 kNm for ITC sago palms when Cd was 0.3, based
clearly showed strong wind
resistance, although there werelarge variations among nativeand Indonesian tissue-cultured
sago palms.
Discussion

1. Wind resistance of the sago
palmBoth unknown adverse effects

on tissue-cultured sago palms

observed in 2012 and the strong
winds of Typhoon Yolanda in2013 might have had negative "  

(Mayhead, 1973). Sago palms

on the calculation from sixteen trees of eight speciesthereafter. The weakness of the family of Palmae
against strong wind varies, depending on the palm

(Iizuka et al., 2011). It is believed that the sago palm is
not strong against wind. The apical part of the trunkand large leaves of the sago palm were blown awayfrom the experimental field (Nishiyama et al., 2014).

However, the lower parts of trunk remained andrecovered over the course of several years. Figure 4

shows the maximum bending moment of sago palms,

 
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   
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Fig 4. Relationshipbetween diameter at breast height and maximum bending






moment of sago palms and coniferous and deciduous trees  

M. Okazaki et al.

6

coniferous trees (Japanese cedar (Cryptomeria

2. Typhoon-prone and sago-growing area inserrata) and Japanese cherry birch (Betula grossa)).

typhoons per year (Japan Meteorological Agency,(2010), Torita (2009), Torita et al. (2010), andtyphoon-prone area. Storm surge heights fromjaponica) and Japanese larch (Larix kaempferi)) anddeciduous trees (birch (Betula), oak (Quercas

The tree data were summarized by Suzuki (2012)
from Mejima and Sasaki (2010), Nakabayashi et al.
Fukami et al. (2011), although the maximum bending
moment values of trees were within 30 cm of thediameter at breast height. Large maximum bending

moment values for sago palms allow us to conclude
that sago palms are stronger against wind even if
other species of deciduous and coniferous trees havea smaller diameter at breast height.

Healthy palms under good conditions carryapproximately twenty-four leaves (Flach, 1997). The

larger the number of leaves the crown carries, thelarger the diameter of the trunk grows. Each month,

one new leaf appears out of the growing point, and theoldest one dies (Flach, 1997). However, Yamamoto(1998) reported that sago palms produced ten leaves

per year on average. No difference in palm height orPhilippines

For 30 years (1981-2010) approximately twenty2019) developed in the Philippine territory andterritorial waters. The east coast of the Philippines is a
Typhoon Yolanda were more than 5 m along the innerpart of Leyte Gulf (Shibayama et al., 2014). One of
the characteristic features of this disaster wasdevastating storm surge induced by a rapid change inwind direction. Sago-growing areas in the eastern partof Leyte Island (Tacloban and Dulag area) have beendeveloped (Quevedo et al., 2005). Sago thatch is a

useful material for Leyte people who utilize it asthatch of houses rather than extracting the starch fromsago trunks after flowering. The thick trunk and hardbark of sago palms can survive when strong winds areattacking their large crown.
Conclusion

There is no research on the comparison of growth

number of leaves was found between NDP and ITC

rate and bending moment of native and tissue-cultured

palms to accelerate seedling production suitable for theIndonesian tissue-cultured (ITC) sago palms in Leyte,sago palms in Pangasugan environment.

Tissue-culture technology has been applied for sago

plantation (Alang and Krishnapilly, 1987). Hisajima etal. (1991) found that multiple shoots were occasionallyobserved from an embryo culture and that verticalhalves excised from seedlings grown in vitro could
grow. In addition Tahardi et al. (2002) reported
somatic embryogenesis in the sago palm. Sinta et al.

(2018) also revealed somatic embryogenesis of thesago palm from different origins in Indonesia. It was

found that the behavior of ITC sago palms against asago palms. We found no difference in the windresistant property between native (NDP) andPhilippines. The strong wind-resistant characteristics
supported the survival of sago palms in the typhoonprone areas of the Philippines.
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