J. Trop. Agric. and Fd. Sc. 26(1)(1998): 65–72 M. N.

Jaafar

The performance of durian clones under supplementary irrigation

(Prestasi klon durian yang diberi pengairan tambahan)

M. N. Jaafar*

Key words: performance, durian clones, supplementary irrigation, water stress

Abstrak
Maklumat khusus tentang tindak balas tanaman terhadap bekalan air diperlukan
untuk merekabentuk sistem pengairan dan menguruskannya. Kajian dijalankan di
dusun durian Stesen Penyelidikan MARDI, Seberang Perai (1992–1995) untuk
menentukan kesan pengairan terhadap tanaman durian. Dalam kajian ini, pokok
durian klon D24 dan D99 yang berumur 5 tahun dibekalkan tiga jumlah air
dengan menggunakan sistem pengairan mikro. Kaedah imbangan air digunakan
untuk menilai jumlah komponen air. Corak penggunaan air setiap perlakuan
dikesan dengan menyukat lembapan tanah di zon akar pada jarak masa dan
tempat yang ditetapkan. Parameter pertumbuhan asas seperti lilitan batang, garis
pusat kanopi dan ketinggian pokok disukat.
Pengairan tambahan pada musim kemarau memberi kesan baik yang ketara
terhadap pertumbuhan pokok sejajar dengan jumlah air yang dibekalkan. Secara
asasnya, keperluan air tanaman durian bergantung pada permintaan atmosfera,
simpanan air tanah di zon akar dan saiz kanopi pokok. Air di zon akar diserap
mulai dari kawasan yang berdekatan dengan batang pokok. Pengambilan air
kemudian menjankau keluar ke arah luar kanopi dan ke bawah sekurang-
kurangnya 1.2 m dalam. Pada kebanyakan bulan, hujan memadai untuk keperluan
tumbuhan. Walau bagaimanapun, kemarau daripada bulan Januari hingga Mac
boleh mengakibatkan kekurangan air yang ketara di zon akar. Klon D24 lebih
peka terhadap ketegasan air berbanding dengan D99. Bagi tanaman tanpa air
tambahan, penambahan ketinggian pokok dan keluasan kanopi lebih kecil dan
daun yang gugur pada musim kemarau lebih banyak daripada pokok yang diberi
air tambahan. Kesan pengairan terhadap penghasilan buah dan bunga tidak dapat
dikenal pasti tetapi D99 menghasilkan buah yang lebih banyak daripada D24.

Abstract
Specific data on crop response to water application are essential for irrigation
design and management purposes. A field experiment was conducted in the
durian orchard at MARDI Research Station in Seberang Perai (1992–1995) to
determine the effect of irrigation on matured durian trees. Five-year-old durian
(clone D24 and D99) trees were subjected to three levels of water regimes using
micro-irrigation system. A water balance method approach was used to quantify
the values of the water components. The water consumption patterns in each
treatment were monitored by measuring the soil moisture changes in the root
zone at discreet time and space intervals. Basic growth parameters such as trunk
girth, canopy diameter and plant height were measured.

*MARDI Research Station, Seberang Perai, P.O. Box 203, 13200 Seberang Perai, Pulau Pinang, Malaysia
Author's full name: Mahmad Nor bin Jaafar
©Malaysian Agricultural Research and Development Institute 1998

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Performance of durian clones under supplementary irrigation

Results indicate that supplementary irrigation during the drought period

contributes to significant growth increments consistent with the amount of water
supplied to meet the deficit. The crop water consumption basically depends on
the atmospheric demand, soil water storage in the root zone and the individual
plant canopy size. Water at root zone is preferentially removed from the area
closest to the trunk. Water uptake then extends radially outwards to the end of
canopy boundary and downwards to at least 1.2 m depth. In most months, rainfall
is adequate to meet the plant water requirement. However, the drought from
January to March can induce severe water deficit in the root zone. The D24 clone
is more sensitive to water stress than D99. Non-irrigated plants have significantly
lower plant height and canopy diameter increments, and a higher leaf drop during
drought than the irrigated plants. The effect of irrigation on fruiting and
flowering is not clear but D99 has significantly more fruit than D24.

Introduction to reduce flower abortion. Nik Masdek

Durian (Durio zibethinus Murr.), the king of (1993) reported that growers in Thailand
Malaysian fruits, is sensitive to water stress. irrigate their crop to balance the
In areas with pronounced drought, crop evapotranspiration (ET) demand, which is
establishment without supplemental water approximately 5 mm/day throughout the
application has a low success rate. As such, fruiting period. For clayey soil, irrigation is
most of the recent durian orchards are applied at 3-day intervals while on sandy
irrigated. Cost of irrigation can be very high soil, water is applied everyday. Presently,
and depends directly on the amount of water irrigation system is designed based on the
applied. The durian tree water needs vary estimated crop water requirement of
with the crop stage and the climatic demand. evergreen trees as recommended by FAO's
Besides these, the soil and clonal differences guideline on crop water requirements
are also known to have mitigating effect on (Doorenbos and Pruitt 1977). For a matured
the durian water requirements. Field durian tree planted at a normal spacing of 10
observations showed that the responses of m x 10 m, the estimated maximum crop
durian trees to irrigation during crop water requirement can reach as high as 360
establishment are encouraging. Masri (1991) L/day. A system design to meet full crop
reported that D24 seedlings are more prone water requirement of this magnitude can be
to drought stress than D99 seedlings. This costly and prohibitive in many cases. Cost
shows that different clones have different can be minimized if specific water
tolerance to water stress. Survival rate of requirement of durian crop is known and
D24 seedlings during the early crop irrigation system is designed to meet the
establishment stage is as low as 50% minimal critical requirement up to the early
compared to 90% for D99 seedlings (Zainal productive stage. Such values can only be
Abidin 1986). justified under field observations.
Available information on the actual A study was, therefore, conducted to
water requirement for field grown durian are determine the effect of water application on
doubtful while published reports on watering developing durian trees of two clones grown
of durian in Malaysia are limited. Abdul in a drought prone area where
Jamil and Ghani (1991) recommended 8–10 supplementary irrigation is mandatory.
L/plant per application every 4–7 days Quantitative evaluation of water requirement
during the first year of field establishment, for irrigated durian orchard was carried out.
and Zainal Abidin et al. (1992)
recommended daily watering at 6–8 L/plant

66
 M. N. Jaafar

Table 1. Physical properties of soil in the experimental site

Soil Saturated Bulk Sand Silt Clay Available % by

depth conductivity density (%) (%) (%) water holding volume
(cm) (mm/day) (g/cm2) capacity (mm)*
0–15 3.0 1.36 59 12 29 14 9
15–30 5.6 1.44 53 10 37 21 14
30–45 2.7 1.44 44 12 44 20 13
*soil moisture contents determined @ 10 kPa and 1 500 kPa

Materials and methods data, viz. girth size at 50 cm from the soil
Irrigation treatments surface, average canopy diameter, plant
The experiment was conducted in the durian height, number of flowers and fruit, were
orchard at MARDI Research Station in collected. Leaf drop from each tree was also
Seberang Perai located in agro-ecological collected during the dry period of 1993.
zone 4 in northwest Peninsular Malaysia The soil moisture status and depletion
from 1992 to 1995. Zone 4 experiences 3 pattern of the root zone were monitored by a
months of drought and 1 month of excessive neutron probe (model CPN 503 DR
rain as classified by Nieuwolt et al. (1982). Hydroprobe, CPN Corp., California, USA).
The soil is a well drained sandy clay loam Readings were taken at 0.15 m intervals
over yellowish-brown gravelly sandy clay of from 0.15–1.50 m depth at 1.0, 2.5, 3.0, and
Hollyrood series, Oxic Dystropept (Wong 3.5 m from the trunks. For the top 75 mm,
1981) and was previously planted with soil moisture status was monitored by
rubber. The soil physical properties are gravimetric method. Weather data, rainfall
indicated in Table 1. The durian trees of and Epan were taken from a weather station
clones D24 and D99 were planted in July about 400 m away from the plot.
1987 at a spacing of 10 m x 10 m on flat
land adjacent to an undulating terrain. Statistical analysis
Standard agronomic practices were followed Randomized block design (RBD) was used
(Zainal Abidin et al. 1992). During the dry in the experiment. Means of the crop
period, the trees were individually irrigated parameters were separated using Duncan
with water from a deep tube well by micro- Multiple Range Test at the 5% level.
irrigation system. ANOVA were determined using SAS
Twelve durian trees of uniform size statistical packages. The statistical design
were selected from each clone from the assumed soil in this field is homogenous.
same field and subjected to three levels of
water regimes (W1, W2 and W3) by Theoretical consideration
controlling the irrigation application rate Quantitatively, water available for a tree
during the irrigation period. Plants in crop may be monitored by a water balance
treatment W1 received no irrigation but technique using the conventional formula:
depended on rainfall only, while those in Θi = Θi-1 + Qp + QI – Qr + Qd + Etc Eqn. 1
W2 and W3 were irrigated at approximately Where Θi = soil water on the day or week
75 and 100 L/day respectively during the in the profile
drought period except during period prior to Θi-1 = soil water on previous day or week
flowering and on weekends. The water was Θp = precipitation
delivered through micro-sprayers and the QI = irrigation
volumes emitted were measured during the Qr = runoff
irrigation period. Irrigation was discontinued Qd = drainage
during the rainy days. The crop performance Etc = actual crop evapotranspiration

67
Performance of durian clones under supplementary irrigation

During the dry period, the component consideration may be referred to Jensen
Qr and Qd are negligible and may be (1980) and Doorenbos et. al (1979).
ignored. The root zone soil water depletion
(Θi – Θi-1) can be represented by: Results and discussion
Θi – Θi-1 = Qp + QI – Etc Eqn. 2 Rainfall and plant growth
The rainfall pattern for 1992–1994 and the
All components of equation 2 can be 10-year average monthly pan evaporation at
measured independently except Etc which is MARDI Research Station, Seberang Perai
essentially equivalent to actual water are presented in Figure 1. The moisture
consumption by the tree, and can be solved deficit duration (rainfall less evaporation) is
from this equation. Alternatively, Etc can normally 5 months in each year, consistently
also be estimated by: during December to February and
Etc = kc ETo Eqn. 3 occasionally in either March, June or July
Where ETo = potential evapotranspiration and September. Even though there is no
(mm/day) water deficit on the yearly basis, the
kc = crop coefficient indicating the monthly deficit is obvious and can be
crop capacity to meet the ETo detrimental to the durian plants. This is
demand especially so during the development stage
when the root zone is shallow and the total
Under non-restricting water condition, plant available water in the root zone is
kc can be expected to be about 1 or greater, critical. Based on the atmospheric demand,
and under restricted plant available water, kc the total moisture deficit for the 5 drought
can be reduced. months during the 3-year period averaged
An independent measurement of ETo , 343 mm/year and amounted to about 23% of
in this case by Epan method, is then used to the 10-year average annual evaporation.
derive the expected kc value for the crop at Growth of perennial crops in this
the particular average moisture condition in environment can, therefore, be expected to
the root zone. Details of this theoretical be reduced corresponding to this moisture

500
Rainfall for 1992
Rainfall for 1993
400 Rainfall for 1994
Evaporation
Amount of water (mm)

300

200

100

0
J F M A M J J A S O N D
Figure 1. Rainfall pattern for MARDI Research Station at Seberang Perai during
1992–1994 compared to the 10-year average annual evaporation

68
 M. N. Jaafar

Table 2. Effect of water level and clone on the growth performance of maturing durian trees at
Seberang Perai, Dec. 1991–Dec. 1993

Treatment Trunk girth Canopy diameter Plant height Leaf drop (g)
increment (cm) increment (m) increment (m) 1993
Water level
W1 (0 L/day) 18.5 1.23a (100) 1.18a (100) 2 831a
W2 (75 L/day) 22.6 1.99b (162) 1.73ab (147) 662b
W3 (100 L/day) 22.8 2.21b (180) 2.04b (173) 612b
Clone
D24 23.3 1.98 1.65 2 142a
D99 19.9 1.63 1.65 596b
Mean values in each column with different letter differ significantly at p <0.05
Values in brackets indicate percentage compared to W1

deficit. Similarly, if water deficit could be Table 3. Effect of water level and clone on the
augmented by supplementary irrigation, growth performance of durian trees after the
corresponding growth difference could be fourth year (Dec. 1992–July 1995)
anticipated. There is no simple correlation of Treatment Trunk Canopy Plant
water-growth relationship. However, over a girth (m) diameter (m) height (m)
few years, the cumulative differences due to
Water level
water stress may be expressed in plant W1 0.79 6.1a (100) 6.24a (100)
growth performance. As shown in Table 2, W2 0.92 6.4ab (105) 6.60ab (106)
the values of some growth parameters for W3 0.88 7.4b (121) 7.22b (116)
the irrigated trees can be higher than those Clone
of non-irrigated trees by more than 50%. D24 0.93a 6.71 6.70
The cumulative growth difference over 40 D99 0.78b 6.54 6.67
months indicated 20% and 16% growth Mean values in each column with different letter
advantage for canopy diameter and plant differ significantly at p <0.05
height respectively. These observations Values in brackets indicate percentage compared
implied that the additional water application to W1
did bring about the anticipated differences in
the crop performance. Daily water which was only apparent after the third year
application at 75–100 L/tree as a supplement (Table 3). The water treatment seemed to
to rainfall registered a tangible growth have no effect on fruiting at this age (Table
difference indicative of the benefit of water. 4). However, D99 as expected had more
The amount of water was predetermined fruit than D24 because it normally fruits
based on the canopy size, the expected earlier and more abundant than D24.
growth during this period and the prevailing The canopy diameter and leaf drop are
atmospheric demand. the most commonly used growth parameters
for indicating water-growth relationship,
Effect of water treatment irrigation design and management purposes.
Water treatments influenced the growth and Leaf drop is an indicator of stress severity.
performance of the maturing durian trees. The dry periods would induce the
Significant growth differences were found physiological system of durian tree to shed
between the irrigated and non-irrigated trees its leaves to minimize water loss. Leaf
in terms of canopy diameter, plant height shedding can lead to slow growth as
and leaf drop (Table 2). There was no indicated in the amount of leaf drop, and the
significant difference between clones in corresponding reduction in canopy diameter
vegetative growth except for trunk girth and plant height for non-irrigated (W1)

69
Performance of durian clones under supplementary irrigation

Table 4. Effects of water level and clone on kc value of approximately 0.7 and 1.0. It
flowering and fruiting pattern, 1993–1995 was about the right amount to meet the daily
Treatment No. flowers/tree No. fruit/tree
requirement during the 1992 period, and was
not too excessive as indicated in the water
1993 1995 1994 1995 content of the soil profile of the irrigated
Water level trees. The depletion level was higher in the
W1 10.5 72 10.3 25 non-irrigated trees compared to irrigated
W2 8.0 83 1.0 35 trees, indicating a greater accumulation of
W3 7.8 72 5.5 37
soil water deficit in the root zone.
Clone
D24 5.8 58 0.8a 4a Progressively, the water requirement of the
D99 11.7 94 10.3b 61b crop increased as the canopy developed.
Generally, rainfall would supplement the
Mean values in the same column with different
letter differ significantly at p <0.05
crop water demand. Deficit in soil water will
manifest if supply cannot meet the demand.
Irrigation water requirement should be met
plants (Table 3). D99 is more drought- to ensure detrimental soil water deficit does
tolerant than D24, as indicated by lesser leaf not occur. The exact amount of soil water
drop during the same drought (Table 2). required varies with different soil type, clone
The sensitive response of the canopy and age of tree. To trigger flowering, a
diameter of durian trees to water treatment slight soil water deficit is required. For our
is not surprising. It confirmed that irrigation experiment, we allowed the stress to last
design for durian trees can then be emulated about one month after the last rainfall prior
based on the established principle of to the drought period.
estimating tree crop water requirement
(CWR) in litres per day given by: Soil water in the root zone
CWR = ETo x CS Eqn. 4 During periods of limited rainfall, available
Where ETo = potential evapotranspiration soil water in the root zone will determine
(mm/day) the supply. The quantity available depends
CS = area of canopy shade (m2) on the volume of root zone and its soil
water storage capacity. For our plot, the soil
By employing this simple formula, the moisture stored in the 1.2 m profile as
CWR for short periods of 5–10 days can be measured by a neutron probe indicated that
estimated quite accurately. As an example, the maximum water content amounted to
CWRs during the drought of 91/92 and 280 mm during the wet period and a
93/94 were calculated. The 5-day average minimum of 170 mm during the dry period.
daily Epan during the drought period ranges Assuming maximum depletion occurred
from 4 to 7 mm/day with an average of 5.6 during these drought periods, then the
mm/day. This value is equivalent to ETo of profile available soil water for plant uptake
4.8 mm/day. The average canopy diameter is at least 120 mm. This amount is sufficient
of the crop were 4.4 m and 6.2 m measured to support CWR for at least 4 weeks of
in December 91 and December 93 normal transpiration. Under reduced
respectively. Based on the canopy diameter transpiration due to leaf drop, curling and
and ETo, and applying equation 4, the daily other physiological adaptation, this amount
consumption during the drought periods of soil water can support the crop through
(January to March) of 1992 was at least the normal dry period albeit under restricted
approximately 73 L/tree, while for the1993 growth. However, root zone of young durian
drought, it was 145 L/tree. plants is shallow and available soil water is
Application of 75 and 100 L/day is correspondingly less. Masri (1990) reported
equivalent to meeting the tree requirement at the root distribution of durian is of inverted

70
 M. N. Jaafar

cone in shape, with most of the root (60% of 290

RLD) concentrated within 60 cm from the

Soil water (mm) in 1.2 m profile

▲
crown and 0–30 cm from the soil surface. 280 ▲

Similarly, soil water depletion due to plant ●

270 ▲
uptake would be expected to be consistent ●
●
with root distribution. Observations on the ▲
260
soil water contents in root zone over a
period of time indicated a similar pattern. 250
The mean of 43 readings (on different
days) of total water content up to 1.2 m 240
● Non-irrigated
depth at 1.0 m from the trunk is smaller than 230 ▲ Irrigated
the values at 2.5, 3.0 and 3.5 m from the
trunk. The daily depletion calculated based 220 ●
on individual tree at a particular event (time 1.0 2.5 3.0 3.5
periods of known moisture contents) Distance (m) from trunk
indicated that durian trees preferentially Figure 2. Soil water contents in the 1.2 m profile
remove the soil moisture from the upper soil at four distances from the trunk of non-irrigated
layer and nearer the trunks. Soil moisture and irrigated durian trees on 10 Feb. 1993
removal then extends radially outwards and
downwards. There were differences in soil
water contents between the non-irrigated 14
Non-irrigated
trees and the irrigated trees (Figure 2). The 12 Irrigated
soil water contents were lowest near the
Soil water depletion (mm)

trunk. There were also differences in 10

depletion levels under irrigated and non-
irrigated condition (Figure 3). The depletion 8
was greater nearer the trunk when
6
antecedent soil water was wet. However, for
the non-irrigated trees, the pattern of 4
depletion had shifted to the wetter area away
from the trunk by the end of February, since 2
the soil water nearer the trunk had already
been depleted earlier and subsequent 0
1.0 2.5 3.0 3.5
depletion was minimal. Distance (m) from trunk
The non-irrigated trees have a higher
Figure 3. Depletion pattern within the root zones
depletion level but at a decreasing rate to as of non-irrigated and irrigated durian trees during
low as 18 L/day as observed during the 10–28 Feb. 1993
11-day rainless period in January for trees
with 3 m canopy radius. The depletion after those of the deeper layers and further away
wet days can be as high as 195 L/day from the trunks.
corresponding to kc value of slightly greater
than one. The durian tree root zone can store Conclusion
a substantial amount of soil water. However, Irrigation system is a necessity for a
prolonged drought can reduce the root successful durian orchard in the drought
zone's soil water content and irrigation is prone areas of Malaysia. The responses of
warranted to meet the crop water crop growth parameters to supplemental
requirement for normal growth. Fluctuation water were at least equivalent to the
of the soil water content in the upper layers percentage of water deficit on the yearly
and nearer the trunk is greater compared to basis. The durian tree preferentially takes up

71
Performance of durian clones under supplementary irrigation

the soil water from the upper layer and Nik Masdek, N. H. (1993). Pengurusan tanaman
nearer the trunk. Water uptake then extends durian: Permerhatian di Thailand. Teknol.
Buah-buahan, MARDI 9: 49–54
radially and downwards towards the wetter
Wong, N. C. (1981). Detailed soil survey of
area. The standard design procedure of using MARDI Bertam Station, Seberang Perai,
the average ET demand and canopy size of MARDI, Selangor
the tree to determine the daily requirement Zainal Abidin, M. (1986). Ciri klon durian D99.
of each tree may be employed. However, the Berita Penyelidikan MARDI 8(3): 4
irrigation water requirement during various Zainal Abidin, M., Ahmad Tarmizi, S. and Azizah,
O. (1992). Penanaman durian p. 34–5.
stages varies with canopy size and daily ETo
Serdang: MARDI
demand. Irrigation at 75–100 L/day per tree
to meet partial water requirement, at
approximately equivalent to kc values of
0.5–1.0 during peak drought at the early
productive years, was vegetatively
beneficial. Variety D99 is more tolerant to
drought and is more productive than D24
though its growth is slower during the early
establishment.

Acknowledgements
The author wishes to express his
appreciation to Mr Yap Beng Ho for helping
in the statistical analysis, Mr Azil Ab.
Rahman for the field work and Ms Fadhilah
Ismail for helping in the preparation of the
paper.

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Doorenbos, J. and Pruitt, W. O. (1977). Guidelines
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p. 48–90. Rome: FAO
Jensen, M. E. (1980). Design and operation of farm
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–––– (1991). Ketahanan klon durian terhadap
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Accepted for publication on 16 April 1998

72