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Agroforestry SystemsAn International Journal incorporatingAgroforestry Forum ISSN 0167-4366 Agroforest SystDOI 10.1007/s10457-016-9974-3
Provenance and pretreatment effect onseed germination of six provenances ofFaidherbia albida (Delile) A. Chev
Charity Fredrick, Catherine Muthuri,Kamau Ngamau & Fergus Sinclair
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Provenance and pretreatment effect on seed germinationof six provenances of Faidherbia albida (Delile) A. Chev
Charity Fredrick . Catherine Muthuri .
Kamau Ngamau . Fergus Sinclair
Received: 3 July 2015 / Accepted: 30 May 2016
� Springer Science+Business Media Dordrecht 2016
Abstract A nursery experiment was conducted to
determine the effects of seed pretreatment methods on
the germination of Faidherbia albida at ICRAF,
Nairobi from six provenances consisting of Awassa,
Taveta, Lake Koka, Maseno, Chinzombo and Wagin-
gombe. Seeds were subjected to five pretreatment
methods namely nicking, soaking in acid, hot water,
cold water and control. Germination percentages (GP),
mean germination time (MGT) and germination index
(GI) were calculated and the data was subjected to
ANOVA. The study revealed significant (p B 0.05)
differences in seed treatments among provenances in
all studied parameters. Highest germination among
pretreatments in Awassa (99 %) and Wagingombe
(80 %) was observed in nicked seeds, Chinzombo
(81 %) in nicked and acid treated seeds, Lake Koka
(90 %) in acid treated seeds and Taveta (28 %) and
Maseno (64 %) in cold water treated seeds. Nicking
gave the highest cumulative GP (69.67) while lowest
GP was observed in hot water treated seeds (23.17).
Acid treatment exhibited lowest MGT (8.85 days) and
highest GI (2.29) while highest MGT (24.35 days) and
lowest GI (0.31) were observed in control and hot
water treatment respectively. Although acid treatment
gave a high GP and lowest MGT and GI, nicking and
soaking in cold water for 24 h is being recommended
as cheaper and less hazardous pretreatment methods to
improve germination in F. albida since sulphuric acid
is expensive and requires proper handling techniques.
Significant correlation between geo-climatic data and
germination parameters of seeds subjected to different
pretreatments indicates that provenances are as impor-
tant as pretreatments in germination of the species.
Keywords F. albida � Provenances � Pre-germination treatments � Germination percentage �Germination mean time � Germination index
Introduction
Faidherbia albida (Del.) A. Chev. (Syn. Acacia albida
Del.), commonly referred to as Apple-ring acacia
(Barnes and Fagg 2003), is a multipurpose leguminous
tree species belonging to the mimosoideae subfamily
(Dangasuk et al. 2011). It is widespread and com-
monly found in all tropical Africa from Senegal to
Sudan and as far as Natal or Angola (Danthu et al.
2002). It grows at low to medium altitudes
C. Fredrick (&)
University of Port Harcourt, P.M.B. 5323 Port Harcourt,
Rivers State, Nigeria
e-mail: [email protected];
C. Muthuri � F. SinclairWorld Agroforestry Centre, United Nations Avenue,
Gigiri, P.O. Box 30677-00100, Nairobi, Kenya
C. Fredrick � K. Ngamau
Jomo Kenyatta University of Agriculture and Technology,
P.O. Box 62000-00200, Nairobi, Kenya
123
Agroforest Syst
DOI 10.1007/s10457-016-9974-3
Author's personal copy
(270–2700 m) in areas of low to medium rainfall
(250–1200 mm/year) and mean temperatures from 18
to 30 �C (WAC 2004). It is also known to grow on the
banks of seasonal and perennial rivers and streams on
sandy alluvial soils or on flat land where Vertisols
predominate. It is very important for agro-silvo-
pastoral as well as soil conservation and soil fertility
improvement throughout the arid and semi-arid areas
(Dangasuk et al. 2011).
Its unique phenology of shedding its leaves during
the rainy season and retaining it in the dry season
improves soil structure, stability and permeability and
also provides shade and mulch which reduces evap-
oration thereby conserving available soil moisture
(Dangasuk et al. 2001). The leaves remain green
during the dry season due to its long tap root
(30–35 m) which is able to utilize deep underground
water (Dupuyl and Dreyfus 1992). Due to its capacity
to fix atmospheric nitrogen, and with its reversed
phenology, F. albida plays an important role in the
protection and improvement of soils as well as in the
increase of crop yield (Danthu et al. 2002). This makes
it an ideal agroforestry tree for use in combination with
crops (Wood 1992). The species is also known to have
high medicinal values; it provides food, furniture, fuel
and can be used for making fences; it also provides
shade and a highly nutritious fodder for livestock
(Kiros et al. 2009). The importance of this species in
agroforestry has made it an important subject for
research. F. albida is mainly propagated by seeds; an
attempt to use artificial regeneration by means of
seedling was not very successful due to poor survival,
slow and variable early growth of the planted trees
(Ibrahim et al. 1997).
Many seeds have difficulty in germination such
that their propagation is adversely affected by seed
coat dormancy which leads to poor growth potential
(Falemara et al. 2014). Botsheleng et al. (2014)
noted that seeds of most arid and semi-arid tree
species cannot germinate promptly when subjected
to conditions favourable for germination due to
impermeable seed coat to water. Also most Acacia
spp have hard seed coats which are impervious to
water (Walters et al. 2004; Aref et al. 2011). Clode
(2011) also noted that many leguminous trees have
hard seed coats and Faidherbia albida is no
exception. Seed dormancy has evolved differently
across species due to adaptation to a prevailing
environment (Botsheleng et al. 2014), it is said to be
a temporary failure of a mature viable seed to
germinate under environmental conditions that
would normally favour germination (Ibiang et al.
2012). The conditions necessary to allow seeds to
‘‘break’’ dormancy and germinate can be highly
variable among species, within a species, or among
seed sources of the same species (Luna et al. 2009).
Several studies have shown that pretreatment may
significantly enhance seed germination of various
tree species (Hossain et al. 2005). Seeds of species
with hard seed coat need to be subjected to some
physical or chemical treatment to break dormancy
and obtain uniform germination (Botsheleng et al.
2014). Different pre-sowing treatment have been
used by different Researchers to enhance seed
germination of different species including Faidher-
bia albida (Diallo et al. 1996), Acacia spp (Aref
et al. 2011); Grewia oppositifolia (Uniyal et al.
2000); Vitellaria paradoxa (Iroko et al. 2013);
Terminalia chebula (Hossain et al. 2005); Te-
trapleura tetraptera (Ibiang et al. 2012); Afzelia
quanzensis (Botsheleng et al. 2014), and Adansonia
digitata (Falemara et al. 2014). However, There are
around 132 provenances of F. albida in Africa all
displaying differences in germination characters and
therefore recommending which pretreatment is suit-
able for which provenance (s) is a big challenge
(Fredrick et al. 2015). There is paucity of informa-
tion on the effect of pre- sowing treatment on
germination of F. albida seeds and also lack of
information on the effect of provenances and
pretreatment on germination of seeds subjected to
different pretreatments. Due to its hard seed coat,
there is poor and prolonged germination of the
species. Diallo et al. (1996) noted that F. albida
produces seeds with hard and impermeable tegument
which becomes an obstacle for it to germinate.
Barnes and Fagg (2003) also reported that F. albida
seeds requires pretreatment to stimulate rapid and
uniform germination. A study to improve the
germination of F. albida by some selected pre-
sowing treatment will help in selecting the most
suitable method to break water impermeable seed
coat of F. albida provenances so as to obtain rapid
and uniform germination of seedlings for application
in agroforestry systems. The objective of this study
was to investigate the effects of provenance char-
acteristics (seed source) and five pre-treatment
techniques on germination response of seeds of F.
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albida in order to identify the most suitable pretreat-
ment method that will increase germination of F.
albida provenances namely Awassa, Chinzombo,
Lake Koka, Maseno, Taveta and Wangingombe,.
Materials and methods
Experimental site
The study was carried out at the World Agroforestry
Centre (ICRAF) nursery in a greenhouse with a
temperature range of 27 and 40 �C, between July and
August, 2014. ICRAF is located about 20 km south-
east of Nairobi, Kenya; at latitude 1�330S and longi-
tude 37�140E, with an average elevation of 1700 m
above sea level. The mean annual rainfall ranges
between 930 and 1500 mm and the annual tempera-
ture range is 16–24 �C.
Seed materials
The seeds of F. albida provenances, namely, Awassa,
Chinzombo, Lake Koka, Maseno, Taveta, and Wagin-
gombe used in this study (Table 1) were obtained from
the ICRAF germplasm laboratory. The seeds were
collected by Oxford Forest Institute for international
provenance trials in 1990 (Fredrick et al. 2015). After
collection, seeds were cleaned and dried immediately
before storage. Seeds were placed in cotton bag and
stored in a cool, dry, and dark place with good air
circulation at -20 �C (WAC 2013). During collec-
tion, 25 mother trees spaced 100 m apart to avoid
collection from related individuals were selected to
represent a provenance (Fredrick et al. 2015). The
samples were representative of the entire natural
distribution range of the species in East and Southern
Africa (EA and SA respectively). In this study, the
term provenance denotes the original geographic zone
from which seeds were collected (Loha et al. 2006).
The location and geographical descriptions of the
different provenances are given in Fig. 1 and Table 1.
Experimental design
The experiment was laid out in a randomized complete
block design consisting of 500 randomly selected
seeds per provenance for the five different scarifica-
tion methods. 25 seeds replicated four times (100
seeds) for each provenance were subjected to a
scarification method giving a total of 3000 seeds (i.e.
25 seeds 9 4 replicates 9 5 scarification meth-
ods 9 6 provenances = 3000 experimental units).
Each treated seed was directly sown in a germination
tray measuring 17 9 13 9 3.5 cm and filled with
sterilized sharp sand and were kept moist by watering
daily. Seeds were germinated under a 50 % light shade
net. No fertilizers or bacterial and/or mycorrhizal
inoculation was used.
Scarification treatments
To investigate the effect of different scarification
methods on the selected provenances, five methods of
scarification were used. These included acid scarifi-
cation, mechanical scarification (nicking), hot water
Table 1 Geographic locations and climatic conditions of the six provenances used in this study (Fredrick et al. 2015)
Provenance Country Zone Geographical location
Lat.–Long.
Altitude (m) Rain (mm) Temp (�C)
Chinzombo Zambia SA 13�080S–32�450E 550 958 24.0
Wangingombe Tanzania EA 08�510S–34�380E 1450 819 20.6
Taveta Kenya EA 03�240S–37�420E 760 545 23.5
Maseno Kenya EA 00�010S–34�600E 1503 119 21.1
Lake Koka Ethiopia EA 08�200N–38�590E 1600 742 10.0
Lake Awassa Ethiopia EA 07�030N–38�280E 1650 961 19.6
EA East Africa, SA Southern Africa
Agroforest Syst
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treatment, cold water treatment and control (untreated
seeds).
Pretreatment procedure
Acid scarification (T1)
In the acid treatments, seeds were placed in heat
resistant non-corrosive glass beaker and concentrated
sulphuric acid (98 %) was poured slowly on the side of
the beaker until all the seeds were covered (50 ml)
(Botsheleng et al. 2014) and left for 30 min during
which they were frequently stirred. Thereafter, treated
seeds were rinsed thoroughly with tap water to remove
all the acid and finally air dried before sowing for
germination (schelin et al. 2004; Asinwa et al. 2012).
Mechanical scarification (T2)
The effect of mechanical scarification was investi-
gated by carefully nicking the seed coat at the distal
end with nail clipper.
Hot water treatment (T3)
In hot water treatments, seeds were placed in fabric
bags and immersed in preheated water at 80 �C and
left to cool gradually at room temperature for 24 h.
Pretreated seeds were air dried before they were sown
for germination (Schelin et al. 2004).
Cold water treatment (T4)
In cold water treatments, seeds were soaked in clean tap
water at ambient temperature (28 �C) for 24 h (Fale-
mara et al. 2013) and air dried before they were sown.
Control (T5)
For control, seeds were not treated. It was conducted to
be able to compare the effect of no pretreatment of F.
albida seeds on germination.
Germination assessment
Germination was recorded daily from the day of
sowing by counting the number of germinated seeds;
Fig. 1 Sources of the
different provenances of
Faidherbia albida used in
this study (Fredrick et al.
2015)
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seedlings were pricked-out after counting to avoid
error. Germination was allowed to proceed for 50 days
after which the experiment was termination. A seed
was considered to have germinated when the hypoco-
tyls hook is evident above the soil surface (Fandohan
et al. 2010). Data collected on germination was used to
calculate germination percentage GP, mean germina-
tion time (MGT) and germination index (GI) for each
treatment using the equation below.
Germination Capacity ðGCÞ
¼ Total germinated seeds
Total seeds sown� 100
1ð1Þ
Germination Index ðGIÞ ¼ G1
1
� �þ G2
1
� �þ ::::::
þ Gx
x
� �
ð2Þ
where G is the germination day 1, 2…, and x
represents the corresponding day of germination
(Botsheleng et al. 2014).
MeanGermination Time ðMGTÞ ¼P
ðtiXniÞPni
ð3Þ
where ti is the number of days starting from the date of
sowing and ni is the number of seeds germinated at
each day (Bewley and Black 1994).
Statistical analysis
Data collected were statistically analyzed using SPSS
statistical software (SPSS version 16.0, SPSS Inc.) to
explore possible treatment variation (Hossain et al.
2005). Analysis of variance was carried out to test the
effect of seed treatments on provenances and Dun-
can’s multiple range test at p B 0.05 level of signif-
icance was used for mean separation (Aref et al. 2011)
after ensuring main effects were significant. All graphs
were plotted using Microsoft excel.
Results
Effect of seed treatment on germination
of F. albida provenances
Seed pretreatment significantly (p B 0.05) affected
germination percentage, mean germination time and
germination index of seeds of F. albida from different
provenances (Table 2). In Chinzombo, mechanically
scarified seeds and seeds treated with acid produced
highest germination percentage (81 %) when com-
pared to hot water immersion (39 %), cold water
immersion (16 %), and control seeds (13 %) which
had the lowest germination percentage (Table 2).
Mean germination time varied among treatments from
7.77 to 37.92 days Highest mean germination time
was observed in control seeds (37.92 days) followed
by hot water immersion (27.34 days) and lowest in
seeds treated with acid (7.77 days). Also Chinzombo
exhibited highest germination index in acid treatments
(2.92) and lowest in control seeds (0.09) (Table 2).
In Wagingombe, mechanically scarified seeds
exhibited highest germination percentage (80 %),
followed by seeds treated in cold water (71 %) while
seeds treated in hot water had the lowest germination
percentage (15 %). Mean germination time ranged
from 7.95 to 22.71 days withcontrol seeds
(22.71 days) exhibiting highest mean germination
time and acid treated seeds lowest (7.95 days),
followed by mechanically scarified seeds (9.83 days).
Germination index was higher in acid and mechani-
cally scarified seeds (2.37 and 2.24 respectively), and
lower in seeds immersed in cold water, control seeds
and hot water, (1.40, 0.79 and 0.25 respectively)
(Table 2).
Taveta exhibited poor germination in all treatments
including control. Germination percentage ranged
from 6 to 28 %. Highest germination percentage was
observed in seeds immersed in cold water (28 %)
followed by mechanically scarified seeds (26 %) and
lowest germination percentage in hot water treated
seeds (6 %). Mean germination time ranged from 9.05
to 22.58 days. Highest mean germination time was
observed in control seeds (22.58 days) while mechan-
ically scarified seeds exhibited lowest mean germina-
tion time. Similarly, germination index ranged from
0.06 to 1.01. Seeds immersed in hot water showed
lowest germination index (0.06) while highest germi-
nation index was observed in mechanically scarified
seeds (1.01) (Table 2).
In Maseno, germination percentage ranged from 29
to 64 %. Seed treated in cold water was highest (64 %)
followed by control seeds (63 %), acid treated seeds
(61 %) and mechanically scarified seeds (55 %),
while seeds immersed in hot water was lowest
(29 %). Mean germination time was significantly
Agroforest Syst
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lower for seeds treated in acid and mechanically
scarified seed (8.56 and 8.73 days respectively) than in
seeds immersed in hot water (24.58 days), cold water
(16.84 days) and control (23.14 days). Germination
index ranged from 0.36 to 2.01 with acid treated seeds
exhibiting highest germination index (2.01 days)
followed by mechanically scarified seed 1.76 days)
while lowest germination index was found in seeds
immersed in hot water (0.36). Note, seeds immersed in
hot water exhibited lowest germination percentage
(29 %), highest mean germination time (24.58 days)
and lowest germination index (0.36) (Table 2).
In Lake Koka, Germination percentage ranged from
27 to 90 %. Seeds treated in acid and control seeds
produced higher germination percentage (90 and 82
respectively) while germination percentage was low-
est for seeds treated in hot water (27 %). Mean
germination time ranged from 7.78 to 19.67 days.
Mechanically scarified seed had the lowest mean
germination time (7.78) followed by seeds treated in
acid (8.09 days) while control seeds had the highest
mean germination time (19.67 days). Germination
index was highest in acid treated seeds (3.06) and in
seeds immersed in hot water (0.40) (Table 2).
Awassa exhibited an excellent germination in all
pretreatments except for hot water treatment. Germi-
nation percentage ranged from 23 to 99 %. Highest
germination percentage occurred in mechanically
scarified seed (99 %), followed by control seeds
(92 %), acid treated seeds in (89 %) and seeds
immersed in cold water (87 %) and lowest in seeds
immersed in hot water (23 %). Mean germination time
ranged from 8.30 to 20.11 days. Highest mean
germination time was observed in control seeds
(20.11 days) while lowest mean germination time
was observed in acid treated seeds (8.33 days).Ger-
mination index ranged from 0.35 to 2.89. The highest
germination index was observed in acid treated seeds
(2.89) followed by mechanically scarified seed (2.86),
while lowest germination index was recorded in seeds
immersed in hot water (0.35) (Table 2).
Correlation between seed geo-climatic variables
and germination parameters in various treatments
Correlation between germination percentage and geo-
climatic data of seed collection sites showed a highly
significant correlation between altitude and germina-
tion percentage in seed pretreated with cold water (T4)
and control seeds (T5), a significant correlation in seed
pretreated with acid (T1) and nicked seeds (T2) and an
inverse non-significant correlation in seeds pretreated
with hot water (T3). Rainfall had a significant
correlation with germination percentage in seeds
Table 2 Effects of seed
pretreatment on mean
germination parameters of
the six F. albida
provenances
Means followed by the
same letter in a row are not
significantly different at
p B 0.05
GP germination (%), GI
germination index, MGT
mean germination time
(days)
Provenances Parameters Acid Nicking Hot water Cold water Control P value
Chinzombo GP (%)
MGT (days)
GI
81c
7.77a
2.92d
81c
10.94a
2.01c
39b
27.34b
0.45b
16a
25.37b
0.18a
13a
37.92c
0.09a
0.000
0.000
0.000
Wagingombe GP (%)
MGT (days)
GI
63b
7.95a
2.37c
80c
9.83a
2.24c
15a
16.23b
0.25a
71bc
14.43b
1.40b
57b
22.71c
0.79a
0.000
0.000
0.000
Taveta GP (%)
MGT(days)
GI
22b
12.41ab
0.50b
26b
9.05a
1.01c
6a
20.25b
0.06a
28b
18.10ab
0.43ab
21b
22.58b
0.27ab
0.002
0.049
0.001
Maseno GP (%)
MGT (days)
GI
61b
8.56a
2.01c
55b
8.73a
1.76c
29a
24.58c
0.36a
64b
16.84b
1.10b
63b
23.14c
0.79b
0.000
0.000
0.000
Lake Koka GP (%)
MGT (days)
GI
90c
8.09a
3.06d
77bc
7.78a
2.73c
27a
17.19b
0.40a
65b
17.10b
1.03b
82c
19.67c
1.23b
0.000
0.000
0.000
Awassa GP (%)
MGT (days)
GI
89bc
8.33a
2.89c
99c
9.34a
2.86c
23a
19.11c
0.35a
87b
15.99b
1.60b
92bc
20.11c
1.37b
0.000
0.000
0.000
Agroforest Syst
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pretreated with acid (T1) and nicked seeds (T2) and a
non-significant correlation with seeds treated in hot
water (T3), cold water (T4) and control seeds (T5).
Temperature had an inverse correlation with germi-
nation percentage in all treatments. Mean germination
time was inversely correlated with altitude and
positively correlated with temperature while correla-
tion with rainfall was not significant. Also germination
index had a highly significant correlation with altitude
in seed treated in nicked seeds (T2), cold water (T4)
and control seeds (T5) and a non-significant correla-
tion in acid (T1) and hot water (T3). Germination
index was positively correlated with rainfall and
inversely correlated with temperature in all treat-
ments. This information is given in Table 3.
Discussion
Seed coat hardness is an important factor that affects
germination in seed (Aref et al. 2011). Seed dormancy
is known to occur in many tropical tree species
(Amusa 2011), most Acacia spp have hard seed coats
which are impervious to water (Aref et al. 2011).
Uniyal et al. (2000) stated that seed pretreatment are
species specific and that no one type of treatment has
been reported to be universally effective. Therefore
breaking the seed dormancy by softening the seed testa
to allow water imbibition is crucial for any afforesta-
tion programs (Aref et al. 2011).
The results of this study showed that all treatment
significantly (p B 0.05) affected various germination
parameters (germination percentage, mean germina-
tion time, and germination index) in all provenances
studied. Mechanical and chemical scarification were
more effective in rendering seeds of F. albida
permeable, leading to a mean germination of up to
69.67 and 67.67 % respectively. Mechanical scarifi-
cation which recorded highest germination percentage
is known to break physical dormancy of hard seed
coats by enhancing gases and water uptake especially
in Acacia species (Missanjo et al. 2014). The enhanced
germination observed in the mechanical treatment
could be attributed to water uptake by the quiescent
dry seed, which ended up with the elongation of the
embryonic axis (Botsheleng et al. 2014). Chemical
scarification also enhanced germination of F. albida
seeds and exhibited lowest mean germination time and
highest germination index. Reduced mean Table
3Pearsoncorrelationcoefficient(r)betweengerminationparam
etersofvariouspretreatm
entandgeo-climatic
variables(m
eanaltitude,
meanannual
rainfallandmean
annual
temperature)ofseed
origin
ofsixF.albidaprovenances
Param
eters
Germinationpercentage
Meangerminationtime
Germinationindex
T1
T2
T3
T4
T5
T1
T2
T3
T4
T5
T1
T2
T3
T4
T5
Altitude
0.425*
0.424*
-0.047
0.937**
0.938**
-0.382
-0.515**
-0.366
-0.750**
-0.733**
0.373
0.613**
0.165
0.892**
0.902**
Rainfall
0.477*
0.657**
0.111
-0.009
0.015
-0.307
0.386
-0.136
0.237
0.256
0.494*
0.499*
0.191
0.020
0.077
Tem
perature
-5.13*
-0.305
-0.093
-0.479*
-6.73**
0.311
0.622**
0.341
0.343
0.509*
-0.462*
-0.590**
-0.260
-0.378
-0.685**
T1Acid,T2Nicking,T3Hotwater,T4Cold
water,T5Control
*Significant,**highly
significancesat
the0.05and0.01levelsrespectively
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germination time in acid treated seeds implies that the
period of dormancy in seeds was reduced due to
pretreatment of seeds in sulphuric acid. It is reported
that acid treatment is an efficient method of enhancing
seed germination of species with hard impermeable
seed coat (Mcdonald and Omoruyi 2003; Likoswe
et al. 2008). It stimulates prompt and uniform germi-
nation of seeds (Agbogidi et al. 2007). Sulphuric acid
is known to disrupt the seed coat thereby exposes the
lumens of the macrosclereids cells, permitting imbi-
bitions of water which triggers germination (Amusa
2011). Agbogidi et al. (2007) also stated that acid
treatment of seeds removes waxy layer of the seed coat
by chemical decomposition of seed coat component
which is similar to breakdown process that occurs
during microbial attack. Hot water treatment exhibited
a low germination percentage (below 40 %) for all
provenances. It was observed that hot water treatment
was not found to be suitable in improving germination
of F. albida provenances. Amusa (2011) stated that
poor germination in hot water treatment could be due
to death of seed embryo as a result of prolonged
contact with hot water. Cold water treatment of F.
albida gave a fair germination percentage and a
reduced mean germination time when compared to hot
water treatment and control. This also implies that
soaking in cold water could also reduce dormancy
period in seeds of F. albidawhen compared to control.
This result concurs with earlier report of Emerhi and
Nwiisuator (2010) and Falemara et al. (2013) which
shows that soaking in cold water is a feature that
enhances germination in seeds of tropical trees. The
control treatment exhibited a lower germination
percentage than cold water and the highest mean
germination time when compared with other
treatments.
This study is in conformity with the work carried
out at the Eden Foundation on how best to establish a
healthy population of F. albida by direct sowing,
without the use of plant nurseries, irrigation or
inorganic fertilizers (Beckman 1990) which reported
that the physical scarification techniques provided the
best results when compared with other treatments.
Jemutai (2011), Barnes and Fagg (2003), Diallo et al.
(1996), Sniezko and Gwaze (1987), Bebawi and
Mohamed (1985) and Halliday and Nakao (1984) also
reported that mechanical and acid scarification gave
the highest germination percentage in seeds of F.
albida. Aref et al. (2011) reported that seeds from four
Acacia species germinated better and faster after
scarification (abrasion and acid treated) when com-
pared to hot water and no treatment. Botsheleng et al.
(2014) and Asinwa et al. (2012) also reported that
mechanical scarification gave the highest germination
percentage in seeds of A. quanzensis and Leucaena
leucocephala respectively and concluded that seed
scarification was the most effective method of
improving seed coat permeability. Poor germination
of F. albida due to hot water treatment has been
reported by Eden Foundation (Beckman 1990). Diallo
et al. (1996) also observed less than 20 % germination
in F. albida seeds subjected to hot/boiling water
methods after 16 days. Bebawi and Mohamed (1985)
warned that boiling water treatment for acacia seeds
was particularly detrimental and could kill most of the
seeds. Similar results have been reported in other
species such as Lupinus hispanicus (Centenera et al.
1999) where poor germination was reported with hot
water treatment when compared to mechanical scar-
ification and immersion in sulphuric acid and A.
quanzensis (Botsheleng et al. 2014) where hot water
treatment had a low germination percentage not
exceeding 40 %. Amusa (2011) also noted that hot
water pretreatment is not an appropriate pretreatment
technology in the seeds of A. africana. Although
Diallo et al. (1996) suggested the use of seed gun
method to treat large quantity of seed quickly since
nicking individual seeds could be labour intensive,
Barnes et al. (1996) concluded that despite the very
large number of seedlings of F. albida to be raised, it
was practicable to nick every seed before germination.
The subsequent increase in the germination per-
centage, decrease in mean germination time and
increase in germination index when subjected to
different pretreatment methods is an indication that
the hard seed coat is responsible for the dormancy in F.
albida. Significant correlation between altitude and
germination percentage in seeds treated in acid,
nicking, cold water and control indicates that seeds
collected from provenances with higher altitude had
higher germination percentage than those with lower
altitudes. Temperature is known to decrease as altitude
increases (Uniyal et al. 2000); this explains the inverse
correlation between temperature and germination
percentage in all treatments. Also provenances with
higher rainfall exhibited higher germination percent-
age in acid treated and nicked seeds. Inverse signif-
icant correlation between mean germination time and
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altitude indicates that provenances with higher altitude
had a lower mean germination time i.e. rapid germi-
nation while provenances with higher temperature had
higher mean germination time in nicked and control
seeds. Non-significant correlation between rainfall
and mean germination time indicates that rainfall does
not have any effect on mean germination time in all
treatments. Significant correlation between altitude
and germination index indicates that seeds from
provenances with higher altitude also exhibited higher
germination index in nicked, cold water treated and
control seeds while seeds from provenances with
higher rainfall had higher germination index in nicked
treated seeds. This implies that seed provenance is as
important as pretreatment, therefore seed collection
should be done at an appropriate altitude, rainfall and
temperature since seed germination can be affected by
climatic condition of seed source.
This finding agrees with the findings of Uniyal et al.
(2000), who also noted that seed source is as important
as pretreatment in seeds of Grewia oppositifolia. The
different response of F. albida provenances to differ-
ent pretreatments shows that seeds of a particular
species collected from different locations will differ in
germination indicating that seed source plays an
important role in the response of seeds subjected to
different pre-sowing treatment. This result is in
agreement with the statement by Luna et al. (2009)
‘That the conditions necessary to allow seeds to
‘‘break’’ dormancy and germinate can be highly
variable among species, within a species, or among
seed sources of the same species’. Differences in
germination of a species from different provenances
subjected to the same pretreatment methods have been
reported by Webb and Farmer (1968) and Uniyal et al.
(2000).
Conclusion
Seeds of most arid and semi-arid tree species areas
cannot germinate promptly when subjected to condi-
tions favourable for germination due to impermeable
seed coat to water. It is also noted that many
leguminous trees have a hard seed coat and F. albida
is no exception. Since the seed coat of F. albida is
hard, it takes more time to germinate with lower
germination percentage in nursery establishment. The
nature and dimension of hard seed coat dormancy in
different species is not fully understood. Therefore,
pre-germination treatments are needed to break phys-
ical dormancy caused by hard seed coat. The objective
of this study was to investigate the effect of different
pretreatment methods on F. albida provenances so as
to determine the most suitable pretreatment that would
enhance and increase germination.
The study revealed the existence of considerable
variation in germination among provenances with
respect to germination percentage, mean germination
time and germination index when subjected to differ-
ent pretreatment methods. Although pretreatment is
not very relevant to reach high final germination
percentage in F. albida provenances (excluding
Chinzombo), it may reduce mean germination time
and increase germination index of F. albida seeds.
Mechanical scarification and acid treatments are the
most effective methods in improving seed germination
of F. albida species by increasing germination
percentage and reducing dormancy period (mean
germination time) but nicking or soaking in cold
water for 24 h is being recommended as cheaper and
less hazardous pretreatment methods to improve
germination in F. albida since sulphuric acid is
expensive and requires proper handling techniques.
Also combined nicking and soaking for 3–12 h could
be used to achieve rapid and maximum germination.
This study also revealed that provenances are as
important as pretreatments. Therefore seed collection
should be done at an appropriate altitude, rainfall and
temperature to enhance germination since seed ger-
mination can be affected by climatic condition of seed
source. The findings of this study will enable selection
of the most suitable pretreatment method for the
different provenances and raising seeds of Faidherbia
albida for easy propagation, domestication and plan-
tation establishment, which will enhance and improve
performance and growth potential of the F. albida
seeds. We recommend that since nicking individual
seeds could be labour intensive, soaking in cold water
for 12–24 h could be used but both methods (nicking
and cold water treatment) are cheap and efficient for
poor farmers although nicking is the best practicable
method to treat every F. albida seed before
germination.
Acknowledgments Authors are thankful to the World
Agroforestry Centre (ICRAF, Nairobi) for providing the
necessary materials for this work. This work was carried out
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under the ‘trees for food security’ project led by ICRAF and
funded by the Australian Centre for International Agriculture
Research (ACIAR). The project is operating in Ethiopia,
Rwanda, Uganda and Burundi and F. albida is one of the
important tree species being studied under the project. We also
want to thank Lucy Mwaura of the ICRAF seed laboratory for
availing the seeds and Julius Njoroge, Agnes Gachuiri, Julius
Kimani and Valentine Gitonga for their support in setting up the
experiment.
Compliance with ethical standards
Conflict of interest The authors declare that they have no
conflict of interest.
References
Agbogidi OM, Bosah BO, Eshegbeyi OF (2007) Effect of acid
pretreatment on the germination and seedling growth of
African pear (Dacryodes edulis [G.Don] Lam.HJ). Int J
Agric Res 2(11):925–958
Amusa TO (2011) Effects of three pre-treatment techniques on
dormancy and germination of seeds of Afzelia Africana
(Sm. Ex pers). J Hortic For 3(4):96–103. http://www.
academicjournals.org/jhf
Aref IM, Ali H, Atta E, Al Shahrani T, Ismail A (2011) Effects
of seed pretreatment and seed source on germination of five
Acacia spp. Afr J Biotechnol 10(71):15901–15910. doi:10.
5897/AJB11.1763
Asinwa IO, Ojo AR, Ezekiel JM, Awosan E, Olaitan AO,
Akanmu OO (2012) Pre- treatment effects on the germi-
nation of the seeds of Calophyllum inophyllum [Linn]
(Indian Laurel). J Agric For Soc Sci 10(1):165–171. doi:10.
4314/joafss.v10i1.15
Barnes RD, Fagg CW (2003) Faidherbia albida: monograph
and annotated bibliography, Oxford Forestry Institute,
Tropical Forestry Papers, No 41
Barnes RD,Marunda CT,Makoni O,Maruzane D, Chimbalanga
J (1996) African acacias: genetic evaluation: phase 1. Final
Report of ODA Forestry Research Scheme R.5653. Oxford
Forestry Institute and Zimbabwe Forestry Commission
Bebawi FF, Mohamed SM (1985) The pre-treatment of seeds of
six sudanese acacias to improve their germination
response. Seed Sci Technol 13(1):111–119
Beckman P (1990) Direct seeding experiments with Faidherbia
albida in an Arid Environment. In: Vandenbeldt RJ (ed)
Faidherbia albida in the West African semi-arid tropics:
proceedings of workshop, 22–26 April 1991, Niamey,
Niger. pp 137–138
Bewley JD, Black M (1994) Seeds physiology of development
and germination. Plenum press, New York
Botsheleng B, Mathowa T, Mojeremane W (2014) Effects of
pre-treatments methods on the germination of Pod maho-
gany (afzelia quanzensis) and mukusi (baikiaea plurijuga)
seeds. Int J Innov Res Sci Eng Technol 3(1):8108–8113
Centenera E, de la Cuadra C, Hill GD (1999) Control of seed
viability in Lupinus hispanicus. Towards to 21st Century.
In: Proceedings of the 8th international Lupin conference,
Asilomar, CA, 11–16 May 1996, pp 416–419
Clode D (2011) Direct seeding Faidherbia albida (syn. Acacia
albida) in the Sahel. https://reafforestation.files.wordpress.
com/2011/09/direct-seeding-faidherbia-albida-in-the-sahel-
final.pdf
Dangasuk OG, Gudu S, Okalebo JR (2001) Early growth per-
formance of sixteen populations of Faidherbia albida in
Semi-Arid Baringo district of Kenya. In: Stott DE, Mohtar
RH, Steinhardt GC (eds) Sustaining the global farm. 10th
International Soil Conservation Organization Meeting.
Purdue University and the USDA-ARS National Soil
Erosion Research Laboratory, 24–29 May 1999,
pp 412–418
Dangasuk O, Gudu S, Okalebo JR (2011) Survival and soil
nutrient changes during 5 years of growth of 16 Faidherbia
albida provenances in semi-arid Baringo district, Kenya.
In: Bationo A et al. (eds) Innovations as key to the green.
doi: 10.1007/978-90-481-2543-2
Danthu P, Hane B, Sagna P, Gassama YK (2002) Restoration of
rooting competence in mature Faidherbia albida, a Sahe-
lian leguminous tree, through serial root sucker micro-
grafting, vol 24. Kluwer Academic Publishers,
Amsterdam, pp 239–244
Diallo I, Danthu P, Sambou B, Dione D, Goudiaby AS, Poulsen
K (1996) Effects of different pretreatments on the germi-
nation of Faidherbia albida (Del.) A. Chev. seeds. Int Tree
Crops J 9(1):31–36. doi:10.1080/01435698.1996.9752957
Dupuyl N, Dreyfus B (1992).Presence of Bradyrhizobia under
Acacia albida. In: Vandenbeldt RJ (ed) Faidherbia albida
in the West African semi-arid tropics. Proceedings of a
workshop, 22–26 April 1991, Niamey, Niger. ICRISAT,
Patancheru, A.P. 502 324, India and ICRAF. ISBN
92-9066-220-4, pp 145–148
Emerhi EA, Nwiisuator D (2010) Germination of Baillonella
toxisperma (Pierrre) seeds as influenced by seed pre-
treatment. In: The proceedings of the 2nd Biennial
National Conference of the forests and forest products
society, pp 323–328
Falemara BC, Nwadike C, Obashola EO (2013) Germination
response of baobab seeds (Adansonia Digitata L) as
influenced by three pre-treatment techniques. In: Forest
industry in a dynamic global environment: Proceedings of
the 35th Annual Conference of Forestry Association of
Nigeria, Sokoto, Sokoto state, pp 44–55
Falemara BC, Chomini MS, Thlama DM, Udenkwere M (2014)
Pre-germination and dormancy response of adansonia
digitata L seeds to pre-treatment techniques and growth
media. Eur J Bot Plant Sci Pathol 2(1):13–23
Fandohan B, Assogbadjo AE, Kakaı̈ RG, Sinsin B (2010)
Variation in seed morphometric traits, germination and
early seedling growth performances of Tamarindus indica
L. Int J Biol Chem Sci 4(4):1102–1109
Fredrick C, Muthuri C, Ngamau K, Sinclair F (2015) Prove-
nance variation in seed morphological characteristics,
germination and early seedling growth of Faidherbia
albida. J Hortic For 7(5):127–140
Halliday J, Nakao P (1984) Technical note on the germination of
leguminous tree seeds. In: Dobereiner J (ed) Simposio
sobre fixacao de nitrogenio em arvores tropicais 19–24 sept
1983, Rio de Janeiro, Pesqui Agropecu Bras 19:231–234
Hossain MA, Arefin MK, Khan BM, Rahman MA (2005)
Effects of seed treatments on germination and seedling
Agroforest Syst
123
Author's personal copy
growth attributes of Horitaki (Terminalia chebula Retz.) in
the nursery. Res J Agric Biol Sci 1(2):135–141
Ibiang YB, Ita EE, Ekanem BE, Edu NE (2012) Effect of dif-
ferent pretreatment protocols on seed germination of Te-
trapleura tetraptera (Schum and Thonn). J Environ Sci
Toxicol Food Technol 2(3):25–29. http://www.iosr
journals.org
Ibrahim AM, Fagg CW, Harris SA (1997) Seed and seedling
variation amongst provenances in Faidherbia albida. For
Ecol Manag 97:197–205. doi:10.1016/S0378-1127(97)001
00-X
Iroko OA, Asinwa IO, KareemAA, Kasim-Ibrahim F (2013) Pre
treatment effects on seed germination of Vitellaria para-
doxa (Gaertn) Hepper. J Agric Sci 3(4):121–125. http://
www.scholarly-journals.com/SJAS
Jemutai T (2011) Efficacy of different pretreatments on dor-
mancy breaking of one provenance of Faidherbia albida
(Del.) A. Chev. A fourth year project report (SBE 403),
Univeristy of Nairobi, School of Biological Sciences, BSc.
Environmental Conservation and Natural Resource Man-
agement. http://erepository.uonbi.ac.ke/bitstream/handle/
11295/72223/Abstract.pdf?sequence=1s
Kiros MH, Lammert K, Walter AH, Ariena HC (2009)
Assessing the effect of Faidherbia albida based land use
systems on barley yield at the field and regional scale in the
highlands of Tigray, Northern Ethiopia. Food Secur
1:337–350
Likoswe MG, Njoloma JP, Mwase WF, Chilima CZ (2008)
Effect of seed collection times and pretreatment methods
on germination of Terminalia sericea Burch. ex DC. Afr J
Biotechnol 7(16):2840–2846. http://www.academicjour
nals.org/AJB
Loha A, Tigabu M, Teketay D, Lundkvist K, Fries A (2006)
Provenance variation in seed morphometric traits, germi-
nation, and seedling growth of cordia africana lam. New
Forest 32(1):71–86
Luna T, Wilkinson K, Dumroese RK (2009) Seed germination
and sowing options. In: Dumroese RK, Luna T, Landis TD
(eds) Nursery manual for native plants: A guide for tribal
nurseries—Volume 1: Nursery management. Agriculture
Handbook, vol 730. Department of Agriculture Forest
Service, Washington DC, pp 133–151
McDonald I, Omoruyi O (2003) Effect of seed pre-treatment on
germination of two surface types of Dialium guianeense.
Seed Technol 25:41–44
Missanjo E, Chioza A, Kulapani C (2014) effects of different
pretreatments to the seed on seedling emergence and
growth of Acacia polyacantha. Int J For Res. doi:10.1155/
2014/583069
Schelin M, Tigabu M, Eriksson I, Sawadogo L, Ode PERC
(2004) Predispersal seed predation in Acacia macro-
stachya, its impact on seed viability, and germination
responses to scarification and dry heat treatments. New For
27:251–267
Sniezko RA, Gwaze DP (1987) Effect of seed treatments on the
germination of Acacia albida Del. In: Kamra SK, Ayling
RD (eds) IUFRO proceedings of the international sympo-
sium on forest seed problems in Africa, Harare, Zimbabwe
1987 Report, Swedish University of Agricultural Sciences
7:325–333
Uniyal AK, Bhatt BP, Todaria NP (2000) Provenance charac-
teristics and pretreatment effects on seed germination of
Grewia oppositifolia roxb—a promising agroforestry tree-
crop of garhwal himalaya, India. Int Tree Crops J
10(3):203–213. doi:10.1080/01435698.2000.9753007
WaltersM,Midgley JJ, SomersMJ (2004) Effects of fire and fire
intensity on the germination and establishment of Acacia
karroo, Acacia nilotica, Acacia luederitzii and Dichros-
tachys cinerea in the field. BMC Ecol 4:1–13
Webb DC, Farmer RE (1968) Sycamore seed germination: The
effects of provenance, stratification, temperature and par-
ent tree. USDA Forest Service Research Note SE-1 00, p 6
Wood PJ (1992) The botany and distribution of Faidherbia
albida. In Faidherbia albida in the West African semi-arid
tropics. In: Vandenbeldt RJ (ed) Proceedings of a work-
shop, 22–26 April 1991, Niamey, Niger. ICRISAT,
Patancheru, A.P. 502 324, India and ICRAF. ISBN
92-9066-220-4, pp 9–17
World Agroforestry Centre (2004). Agroforestry tree database
World Agrofrestry Centre (2013) ICRAF tree seed handling and
dissemination processes: A simple guide for use by tree
seed dealers, students and extension officers
Agroforest Syst
123
Author's personal copy