IJERD – International Journal of Environmental and Rural Development (2022) 13-1

Research article
erd

Nursery Propagation of Apple Mangrove Sonneratia alba
ARNIE C. TRANGIA*Cebu Technological University, Cebu City, Philippines
Email: arnie.trangia@ctu.edu.phReceived 7 February 2022

Accepted 2 May 2022(*Corresponding Author)

Abstract Mangrove rehabilitation conducted on the seafront was a failure because of small
survival due to wrong species planted and zonation. Apple mangrove (Sonneratia alba),"pagatpat," is the most widely distributed mangrove globally, particularly in coastal regions.
The study showed that the Sonneratia species bears plenty of fruits, but seedlings rarely
grow in the wild. The researcher introduced a ninety-day analysis using various soil media
and different watering regimes in a designed concrete tank to determine the survival andgrowth rates of the nursery propagated apple mangrove seedlings. He observed that thehighest average survival rate of S alba seedling was in watering regime Treatment 3 and thetype of soil medium was sandy clay. The researcher measured the average survival rate at
23.70% in clay, 52.10% for sandy clay, 44.32% for sandy soil under a watering regime,
37.41% in clay, and 43.21% in sandy clay, and 39.41% in sandy soil. Research showed thatthe seedlings watered under Treatment 3 observed the highest growth gain (5.41 ± 0.68 cm),while seedlings under Treatment 1 recorded the lowest growth gain (1.87 ± 0.23 cm) under
the watering regime. Seedlings planted in sandy-clay soil exhibited the highest growth gain
(4.15 ± 0.52 cm), while seedlings planted in clay recorded the lowest growth gain (4.0 ±0.50 cm) for soil media. Moreover, the researcher observed that growth showed asignificant difference in the different watering regimes but had no significant difference inthe type of soil media.
Keywords apple mangrove, water regimes, soil media, survival rate, growth rate

INTRODUCTION
The Philippines is ranked fourth out of the 180 countries in the 20 years (2000-2019), following
Puerto Rico, Myanmar, and Haiti among the countries most affected by extreme weather according
to the Germanwatch report (Global Climate Index, 2021).
Mangroves are a natural coastal defense against violent storms that bring storm surges andflooding. It is one of the most effective mitigating measures against climate change. In addition,
mangroves can hold back the sea waves and reduce wave forces with their extensive and dense
above-ground roots by an estimated 70-90% on average (Macintosh, 2010). Furthermore, a study
conducted by Harada et al. (2012) demonstrated that mangroves are as effective as concrete seawall
structures in reducing tsunami-hit house damage behind the forest.
Mangrove systems have contributed significantly to the well-being of coastal communities
through a wide array of ecosystem services classified into regulating, provisioning, cultural, andsupporting (Manual on Community-Based Mangrove Rehabilitation: Box 1, 2012). Fringing
mangroves in the Philippines and the rest of Southeast Asia are naturally lined by a band of
Avicennia marina and Sonneratia alba front-liners with Rhizophora stylosa and R. apiculate
immediately behind (Manual on Community-Based Mangrove Rehabilitation, p. 6, 2012).
Primavera et al. (2014) averred that Sonneratia alba (pagatpat) dominates the eastern Panay
coastline. The species has been proven superior even to the Avicennia marina for the rehabilitationof sandy fringes. Most of the plantations used Rhizophora species whose propagules are easy tocollect and plant but which cannot withstand wave action. Hence only 10% of these plants survived
in open seaward sites in Calauag Bay, Quezon. These activities can best describe as planting byconvenience rather than ecology (Primavera, 2005; Primavera and Esteban, 2008).
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Avicennia marina and Sonneratia alba are the two significant fringing colonizers of thecoastlines. However, wildlings are much rarer than the latter, and nursery techniques are relatively
undeveloped compared to the first, according to protocols for growing Sonneratia alba (Mangrove
Manual Series No. 2: Box 7, 2012).
Mangrove rehabilitation/reforestation programs in seafront areas and building coastal
greenbelts as a mitigating measure in protecting coastal communities can still be a total failure.
Develop the nursery propagation of apple mangrove first since this species is the primary colonizerof the sandy fringing coastlines. It is a suitable mangrove species to be planted in the seafront zone.
Moreover, it is bigger, sturdier, and can withstand nature's forces as compared to the usual
Rhizophora species.
The study used a tide simulation to address the gap using different watering regimes of pure
seawater and various soil media. Using a concrete tank regulates the additional watering controls.
Inundation of seawater to the seedlings should not be more than 30 percent of the time per day. The
production of nursery propagated seedlings will fill the gap of the rareness of apple mangrove
seedlings. The establishment of mangrove nurseries can provide mangrove seedlings of therequired species in the required numbers and sizes at a given time; otherwise, planting will behighly dependent on the availability of propagules, seeds, or wildlings (Mangrove Manual SeriesNo. 1: Box 3, 2012).
OBJECTIVE
The purpose of this research study is to produce nursery reared apple mangrove seedlings to supply
the much-needed right planting materials and to correct the existing practice of coastal mangrove
rehabilitation/reforestation using Rhizophora species. Specifically, the study aimed to: (1)determine the survival rate of Sonneratia alba seedlings reared in three types of soil media using
different watering regimes; (2) assess the growth rate of apple mangrove seedlings reared in threetypes of soil media using different watering regimes; and (3) conduct pilot testing to assess what
type of soil media and corresponding watering regime propagated apple mangrove seedlings growbest.
METHODOLOGY
The environment: The researcher conducted apple mangrove (Sonneratia alba) nursery
propagation research in Daanbantayan, Cebu, Central Philippines.

LEGEND:T1= watered with seawater once a day (the natural way)
T2= watered once a day (totally submerged for two hours)
T3= watered with seawater twice a day (totally submerged for two hours for each treatment

Fig. 1 The design of the research tank
The concrete tank: The study used a concrete tank measuring 8 meters in length by 2 meters inwidth by 0.24 meters in depth (8 m x 2 m x 0.24 m.). The tank is further subdivided into 16
compartments; measuring approximately one square meter in area respectively (Fig. 1).

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The plant pot and soil media: The research used 18 centimeters in diameter synthetic pots in its
top portion by 15 centimeters in height, and it utilized three types of soil media treatments, sandy,sandy clay, and clay. Each treatment used nine pots, each filled with the corresponding soil. Since
there will be three treatments with five replications, the total number of banks used was 45 in eachtreatment or 135 pots for all the three treatments.
Seedling preparation phase: Mature bigger fruits that had no holes bored by insects do not sufferfrom extreme weather conditions, and were ripe in a good parent tree, were collected early in themorning or late in the afternoon through handpicking. Fruits of S. alba will freely fall when ripeand mature and naturally separate from their calyx before dropping to the ground (Fig. 2).

Fig. 2 Ripe fruit and seeds of Sonneratia alba ideal for collection
By using the bare hands, macerate the fruits by pressing. Usually, the number of seeds foundinside ranged from 80 to 160. The seeds were soaked and washed in a basin withfreshwater/rainwater and let stand for a few minutes allowing the viable seeds to float. The seeds
were dried for 2 to 3 hours to break seed dormancy. Avoid prolonged drying of sources, for it willaffect seed germination.
The study utilized seedboxes measuring 40 x 90 cm. Sandy clay soils were used as soil
medium (5-7 cm thickness) and taken from the parent tree area. The seeds were soaked overnightwith rainwater to hasten germination. After twenty-four (24) hours, the seeds that showed signs ofsprouting were collected and sown in the seedboxes, covered with 2.54 cm-thick soil, and allowed
to germinate for one month before transplanting individually. Water the seeds with rainwater
diluted with seawater to acclimatize the seeds. After 30 days of propagation from the seedbed, theresearcher transplanted the seedlings.
Experimental phase: The tank's 15 compartments should be re-checked carefully for its watertightworthiness by filling the tank with seawater and cross-checking the draining system to see if it
functions well. The study closely followed the watering regime scheduled time during the floodingof the tanks. The researcher should do general cleaning of the tank every fifteen days.
Watering regimes: In treatment 1, the plants were watered once, just like ordinary plants.
Treatment 2 was submerged once for two hours daily, and Treatment 3 was submerged twice fortwo hours in each submersion. Two cm above the apex of the seedling's leaves, seawater wasinundated. Drain the tank's compartments by pulling out the cover of the drainage pipe after twohours. The researcher simulated treatments like the tide of the sea, which coincides with the study(Kjerfe 1990) that mangroves grow at or above mean sea level or MSL, which is not more than thesea 30% of the time tidally inundated.
Seedling management: The study used three treatments of different soil media and three watering
regimes with five replications each. The study needed an adequate and accessible supply of clean
seawater to efficiently facilitate the filling-up and drain of the seawater in the tank. The project
should strictly follow a watering schedule. After ninety (90) days of managing period, the seedlings
are now ready for extension purposes by planting the produced seedlings in the selectedrehabilitation areas.

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Collection of data: During the initial stage of transplanting, the seedlings had an initial height of 2centimeters. The researcher measured the seedlings from the top of the soil to the last middle leafof the plant. Every 15 days, the plant's data, survival, and growth rate were taken and monitored forthree months.
Statistical treatment: The study used a Randomized Complete Block Design (RCBD) research
design. A two-way ANOVA of SPSS Statistics to get the mean difference to determine if there is asignificant difference in survival rate and growth rate in the three watering regimes and threedifferent soil media. The variables studied survival rate and growth rate. The study used following
Equation (1) to get the survival rate.
Number of survivors
Surviving rate =(1)x 100
Initial number

The growth rate was taken using following Equation (2).
Growth rate = Height 1 - Height 2/ Height 1 x 100(2)

RESULTS AND DISCUSSION
Survival rate: Figure 3 showed a significant relationship between the watering regime andSonneratia alba's survival. The survival rate of S. alba was highest in Treatment 3, was increased inTreatment 2, but very low in Treatment 1. The experiment implies that the inundation of seawater
twice daily favors the survival of Sonneratia alba seedlings as long as the submersion time was not
more than 30% of the time. The inundation of fresh seawater brought nutrients to seedlings. The S.
alba average survival rate in the three watering regimes is highest in sandy-clay soil with 43.21%,
sandy soil with 39.41%, and clay with 37.41%.

Fig. 3 Survival rate of the apple mangrove seedlings in various treatment
The study implies that in the soil type where most of its parent trees lived, S. alba seedlings
survive best. However, this is in contrast to Deloffre et al. (2006) and Viles et al. (2008) study,
which showed that for both Aviccenia and Sonneratia, short inundation (5 h day -1) without
sediment treatment resulted in 100% survival throughout the experiments.
Results of analysis of variance (ANOVA) computation revealed a significant relationship on
the survival of S. alba in different watering regimes (p=.000<0.05) at a 5% level of probability; but
has no meaningful relationship with the survival of S. alba in other soil media (p=0.493 > 0.05) at
5% level of probability also. Furthermore, it has no significant effect on the survival of S. alba
seedlings in the different watering regimes and soil type interaction (p=0.125>0.05) at a 5%
probability level.
ANOVA implies that within the duration of the study the survival of S. alba seedlings has asignificant difference when watered naturally, submerged once a day, or submerged twice a day but
has no significant difference when grown in clay sandy clay or sandy soil. Moreover, the survivalⒸ ISERD187

IJERD – International Journal of Environmental and Rural Development (2022) 13-1of S. alba seedlings has no significant difference whether watered naturally, submerged once a day,or submerged twice a day interacted with different soil mediums.
Table 1 Analysis of variance (ANOVA) table on survival rate
SourceCorrected modelIntercept
Watering regime
Soil type
Watering regime * Soil type
ErrorTotal
Corrected total

Type IIISum of squares
9720.335a
86577.691
7753.435
311.275
1655.626
9746.515
106044.541
19466.850

Meansquare1215.042
86577.691
3876.717
155.637
413.906
216.589

df
8
122
4
45
54
53

F

P-value

5.610
399.732
17.899
.719
1.911

.000
.000
.000
.493
.125

Growth rate: The study used an estimated margin of 4.0 cm to interact with the watering regime
and soil type if it affects the growth of the S. alba seedlings. All the seedlings planted in different
soil media interacted with the watering administration. The study found that Treatment 3 andTreatment 2 were above the estimated marginal means.

y = 0.34x + 4.73
R² = 0.9772
5.10
4.57

2.32

5.78
5.27
y = 0.35x + 4.1933
R² = 0.9829

5.354.84

y = -0.46x + 2.7867
R² = 0.9994
1.88

1.40Fig. 4 Growth rate of the apple mangrove seedlings in various treatment
It means that the result of the study coincides with the report of Kjerfe (1990) that mangroves
grow at or above mean sea level or MSL, which is not more than 30% of the time tidally inundated.
Results of Analysis of Variance (ANOVA) showed a significant relationship on the growth ofS. alba in different watering regimes (p=.000<0.05) at a 5% level of probability; but has no vital
relationship with the survival of S. alba in other soil media (p=0.9777>0.05) at 5% level ofprobability also. Furthermore, it has no significant effect on the survival of S. alba seedlings in thedifferent watering regimes and soil type interaction (p=0.909>0.05) at a 5% probability level.
Table 2 Analysis of variance (ANOVA) table on the growth rateSource
Corrected modelIntercept
Watering regime
Soil type
Watering regime * Soil type
Error
Total
Corrected total

Type IIISum of squares
137.488a888.491
132.035.240
5.213
235.939
1261.918
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df
8
1
22
445
54
53

MeanFsquare
17.1863.278
888.491 169.460
66.018 12.591.120.023
1.303
.249
5.243

P-value.005
.000
.000
.977
.909

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It implies that within the span of the study from days 0-90, the growth of S. alba seedlings hasa significant difference when watered naturally, submerged once a day, or submerged twice a day
but has no significant difference when grown in clay, sandy-clay, or sandy soil. Moreover, thegrowth of S. alba seedlings has no significant difference whether watered naturally, submerged
once a day, or submerged twice a day interacted with different soil mediums whether grown in clay,
sandy clay, or sandy soil.
CONCLUSION
The study can conclude that the soil medium having the highest average survival of Sonneratia
alba seedlings grown in the concrete tank is the sandy-clay soil. The ideal watering regime for their
growth is Treatment 3, in which the seedlings are submerged twice for two hours per submersion.
With this study, the production of the correct species of mangrove seedlings is available, and theoutput can correct the present trend of mangrove rehabilitation/reforestation. Because of thisresearch saves much time, effort, and money. The paper can realize the long-term dream ofbuilding coastal greenbelts to make the coastal community well-protected and resilient against thethreats of climate change and global warming.
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