Effect of root growth potential, planting distance and provenance of Gmelina arborea

ASIA LIFE SCIENCES 21(1): 1-18, 2012
The Asian International Journal of Life Sciences

Effect of root growth potential, planting distance
and provenance on the growth and survival of
Gmelina arborea Roxb.

ONOFRE S. CORPUZ1* and WILFREDO M. CARANDANG2
The study was conducted in Matalam, Cotabato Southern Philippines to test the effect
of root classes, provenance and distance of planting on early field survival and growth of
Gmelina. The experimental design used in the study was a strip-split plot design with three
replications. Analysis of variance revealed significant differences in the growth of Gmelina
after one year. Strong genetic control over height, basal area, and biomass were found. This
result was supported by the positive and significant relationship of provenance with the
same traits. Seeds from Quezon were significantly different in terms of merchantable and total
height compared to Cotabato and Davao del Sur seed sources. While in terms of basal area and
biomass, Quezon and Cotabato did not differ significantly. On the other hand, the three
provenances did not vary significantly in terms of diameter breast height (dbh), tree volume
and survival. Distance of planting also insignificantly affects height, diameter growth and
survival of the tree. However, basal area, tree volume and biomass varied significantly.
Root classes affected tree diameter, total height, survival rate, and volume significantly. All
factors did not show variation on basal area, and merchantable height. Root classes were
found to be positively and significantly correlated with dbh, basal area, root and total tree
biomass.

Key words: germination, survival rate, seed provenance, planting distance, root classes,
growth, tree volume, Philippines

1

Departmen of Forestry, College of Agriculture, Cotabato Foundation College of Science and
Technology, Doroluman Arakan, 9417 Cotabato Philippines. *Corresponding author

2

Institute of Renewable Natural Resources (IRNR), College of Forestry and Natural Resources
(CFNR), University of the Philippines Los Baños, College 4031, Laguna, Philippines.

Received 06 March 2011; Accepted 30 May 2011.
©Rushing Water Publishers Ltd. 2012.

Printed in the Philippines

Corpuz & Carandang 2012
INTRODUCTION
In the Philippines, many studies on seedling attributes dealt with morphological
traits. Only a few studies investigated root growth in relation to field planting
performance. Root growth potential (RGP) is seldom used as a measure of seedling
quality. Elsewhere, studies were done chiefly on temperate tree species such as
Pinus radiata (Rook 1971), Sitka spruce (Deans et al. 1990), Douglas-fir (Cannel et al.
1990, Sharpe & Mason 1992, Rose et al. 1991, Hasase & Rose 1994), Loblolly pine
(Larsen et al. 1986, Williams 1972, Fere & Krebs 1985), Slash pine (McGrath &
Duryea 1994) and Ponderosa pine (Stone & Jenkinson 1959). Gazal (1998) studied the
root growth potential of Narra (Pterocarpus indicus Willd.) transplants as influenced
by moisture level.
Methods of measuring RGP have already been standardized in many temperate
countries but this has not been done in the tropics including the Philippines (Gazal
1998). The potential of using RGP as an indicator of seedling quality and performance
of one important tree species in the Philippines needs to be explored. This study
attempted to provide a basis for interpreting RGP and early field performance of
Gmelina arborea Roxb., one of the most common exotic tree species used for
reforestation and industrial tree plantation in the country now.
The relationship between root system development of planted forest tree species
and its survival, stability and growth has gained considerable research interest (Van
Eerden & Kingshorn 1978, Coutts & Lewis 1983, Deans & Ford 1983). Seedlings
established naturally have been found to have a stable root configuration with well
developed tap roots and evenly distributed lateral roots, whereas bare root transplants
were often less stable having irregularly distributed root system (Chavasse 1978,
Burdett 1979a). High root growth capacity of plants and planting stock has been
reported to have improved survival after field planting and growth rates (Stone &
Jenkinson 1970, Burdett 1979, Sutton 1980, Burdett et al. 1983, Burdett et al. 1984).
RGP must be capable of being interpreted on site, relating physiological
attributes to the conditions of the intended field environment would aid allocating
stock to plantations. The use of on-field interpretations of RGP has not been tested
under well-defined field environments. That is, planting stocks with high RGP are
expected to survive and perform better on sites than those with low RGP. Seedlings
with low RGP are assumed to be more prone to damage under harsh environmental
conditions than those with higher RGP.
Seedling performance in the planting site depends on its growth potential and
the degree to which conditions in the area allow its growth potential to be expressed.
The degree to which seedlings are conditioned to the environment in the planting
site will have the greatest influence on their performance immediately after planting.
Thus, foresters and nurserymen should come up with a planting stock assessment
procedure that anticipates prevailing conditions in the area to be planted.
The few planting stock assessment schemes being done in the country considers
the top of seedlings as the basis for judging their quality. Seedling tops are very
visible and top growth can easily be manipulated by nursery techniques (Carandang
1994). Thus, with these schemes, the quality of planting stocks is usually evaluated

2

Asia Life Sciences 20(1) 2011

Growth and survival of Gmelina
primarily through height, root collar diameter, and top/root ratio. Again, these
characteristics or measurements can be readily altered by nursery practices.
In an industrialized country, emphasis is now being given to the roots as the
basis for judging seedling quality. A new scheme has been developed for the grading
of nursery seedlings which considers the RGPs of seedlings. There is a growing
body of evidence that support the notion that the number of lateral roots upon lifting
the seedlings from the nursery directly affects the survival and growth of the same
after field planting (Carandang 1994). The RGP of a seedling reflects the seedling’s
ability to initiate and elongate roots when it is placed into an environment favorable
for root growth (Ritchie 1985). RGP has been considered to be positively correlated
to seedling survival and growth (Burdett et al. 1983, McCleary & Duryea 1987). This
study sought to determine the suitability of RGP in evaluating seedling field
performance under Philippine conditions using G. arborea, one of the most commonly
used exotic species for tree plantation in the country. Other variables considered in
the test included the effects of distance of planting, and provenance.
The objectives of this experiment were: (a) to determine the effect of RGP on
field performance and survival of G. arborea species; (b) to evaluate the suitability of
RGP as a measure of seedling quality through actual field trials as affected by distance
of planting, and provenances; (c) to test whether RGP of Gmelina arborea is closely
related to stem and other root morphological characteristics and (d) to determine the
family mean heritability of first order lateral root (FOLR) of the species.

MATERIALS AND METHODS
The seeds of Gmelina from three provincial sources such as Quezon, Cotabato,
and Davao del Sur were raised in the nursery of Arakan, Matalam, Cotabato. After
60 days, the seedlings are carefully lifted from the seed bed and washed with running
water throughout to remove excess soil particles. Number of FOLRs developed were
counted to establish root groupings for Gmelina by provenance. The seedlings with
three root groupings established such as R1 (0-10), R2 (11-20) and R3 (21-30+) by
provenance were immediately outplanted in the field at different spacing arrangement,
namely: 2 x 2 m, 2 x 3 m and 2 x 4 m following a strip-split plot design with three
replications.
The experiment was established in a 1.021 ha. cogonal field of Arakan Matalam,
Cotabato (Figure 1) in November 6, 2006. The area of the plots were varies according
to distance of planting. The 2 x 2 m had 756 m2 area, 2 x 3 m had 1134 m2 and the
2 x 4 m had an area of 1512 m2. The soil in the experimental site is silty clay with pH
value ranging from 6.2-7.2. The soil nitrogen is low with moderate phosphorus and
potassium content. The rainfall recorded during the conduct of the study was
2,084.6 mm. The highest amount was obtained in June (378.9 mm) while the lowest
was in February (51.52 mm).
Collection of data started after 30 days was undertaken monthly afterwards
throughout the duration of the study. Stem diameters and heights were measured. Six
months after outplanting of the seedlings, corn were inter-planted but data analysis
disregarded the effects of the annual crops on the growth and survival of the Gmelina
tree.


3


Figure 1. Map showing the study site - Matalam, Cotabato Province, Mindanao,
Philippines.
Data analysis. Analysis of variance and regression procedure were employed in the
analysis of data using SAS software for faster and appropriate data analysis and
interpretation. The field performance of the tree species in terms of height and diameter
as affected by root classes, distance of planting, provenance and interactions of all
variables were statistically calculated using strip-split plot design analysis of variance.
The presence or absence of G x E interactions in all morphological characters of the
plants was determined from the resulting ANOVA.
Family mean heritability of all seedlings morphological characters were estimated
based on the analysis of variance of plot means. The narrow sense heritability is
computed using the following equation derived from ANOVA:

h2 = MSF - MSFxR
MSF

(1)

where: h2 = narrow sense heritability;
MSF = mean square value for family;
MSFxR = mean square value for family by replication
interaction

4


RESULTS AND DISCUSSION
Survival rate. The rate of Gmelina trees survived in the field after one year revealed
no significant differences among provenances and distance of planting. However,
survival rate was significantly different in terms of root classes (Figure 2).
The survival rate of Gmelina trees belonging to root classes 2 and 3 were
significantly higher than those in root class 1.
Landis and Skakel (1988) claimed that RGP tests do not predict actual planting
performance as they predict only the survival potential of the seedlings. Thus, the
more new roots developed in a seedling, the better potential for growth and survival.
This was supported by the study of Feret and Kreh (1985) which said that one of the
preconditions for the survival and rapid growth of transplants after outplanting is a
high RGP.
A capacity for root growth will not only mean that the root system is active or
alive but also effectively capable of absorbing water and nutrients. Thus, RGP provides
a measure of the functional integrity of the whole plant (Ritchie 1984).

Figure 2. Survival rate of Gmelina as influenced by (a) provenance; (b) root classes
and (c) distance of planting.
RGP is not limited to its predictive ability to determine the potentials for field
survival but the health and vigor of the seedlings as well.
Blake et al. (1989) reported the relationship between outplanting survival and
stem diameter for Douglas-fir. They found that the relationship between survival and
diameter was affected by seedling root mass, especially for smaller diameter seedlings.
Seedling with good root mass consistently survived better that those with poor root
mass (Mexal & Landis 1990).
Height and shoot size are poor indicators of seedling survival; however, if the
seedling survives, initial height has been shown to be linearly related to further
height growth in some species (Mexal & Landis 1990).
Root collar diameter on the other hand is a better indicator of survival and
performance partly because it is related to the size of the root system and partly
because a large stem diameter makes the seedling sturdier and increases the stem


5

area available for water transport. Studies with Loblolly pine have shown survival
and growth to be positively correlated with seedling diameter (South et al. 1989).
Sturdiness quotient or the ratio of height to root collar diameter, is a combination
of two traits used as a stock quality test in New Zealand (Hawkins, undated).
Hashizume and Han (1993) showed that the height of Sawtooth oak (Quercus
acutissima Carruth) seedlings was an important factor in determining growth and
survival, with the tallest trees (>150 cm) having lower survival percentage than trees
100-120 cm in height.
The amount of new roots developed after field planting determines the initial
survival of the seedlings. Hence, the threshold RGP value critical for the stock to
achieve its field performance potential must be established per seedling. Simpson et
al. (1988) proposed an RGP threshold value of 0 root greater than 10 mm in length per
seedling as a batch culling guidelines for several Northwest conifer species (Landis
& Skakel 1988). The same threshold value was also suggested by British Columbia
for interior spruce and lodgepole pine (Ritchie & Tanaka 1991). It was further
recommended that threshold values should also be determined for other species for
which positive correlation between RGP and field performance has been found
threshold values may vary among planting sites and year. Using a stochastic model,
it may be possible to define RGP level with 95% confidence for any planting site and
year. The said model would be able to specify the nursery cultural practices, lifting
dates, cold storage and field handling and planting procedures needed to attain the
required RGP for successful field performance (Feret & Kreh 1985).
Tree height. The trend of the monthly height growth of Gmelina up to one year
followed a typical sigmoidal behavior (Figure 3). Abrupt growth was observed during
the start of the rainy season in June. The monthly height growths of the trees from
the different seed sources were significantly different in terms of provenance up to
one year.
Height in terms of distance of planting was only significant up to the 10th
month and became insignificant afterwards.
On the other hand, height differences as affected by root classes was significant
up to the 6th month but became insignificant in the succeeding months. The interaction
effects of the provenance x distance of planting (F x D) were consistently significant
up to the 10th month but insignificant differences appeared on the 11th to 12th months.
Provenance x root classes (F x R) interaction was significant up to the 9th month but
became insignificant during the 10th to 12th months.
Merchantable height revealed significant differences in terms of provenance
but not in terms of distance of planting and root classes. The trees from Quezon were
significantly higher with those from Davao del Sur and Kabacan, Cotabato (Table 8).
Total height revealed significant differences in terms of root classes. Root classes
3 and 2 are significantly different with root class 1. Provenance and distance of
planting did not show significant variations in terms of total height growth of Gmelina.
Data from Jacobs and Siefert (undated) indicated that FOLR was a poor predictor of
height growth of northern red oak, white oak, and black cherry (Prunus serotina
Ehrh.) after 1 year. In the sweetgum research of Belanger and McAlpine (1975), stated

6


that the growth response of various root collar diameter grades was obvious after the
first growing season and continued through the seventh season. At that point, trees
from the largest seedling grade averaged 1.95 m (6.4 ft) taller than trees from smaller
grade. For the interaction effects, only F x R revealed a significant result, the rests
were all insignificantly varied.

Figure 3. Monthly height growth of Gmelina as affected by provenances, planting
distance and root classes.

Tree diameter. The monthly diameter growth trend of the Gmelina tree one year after
field planting was shown in Figure 4. Abrupt growth started in April four months after
field establishment with the occurrence of slight rain. The cultivation of the field in
preparation for the planting of corn could have triggered this rapid growth.
Diameter growth of Gmelina in the field revealed significant results in terms of
provenance and planting distances up to one year. The diameter in terms of root
classes revealed no significant differences up to the 8th month. However, in the 9th to
12th month the differences became significant. The environmental factors which
contribute significantly to the overall make-up of the plant constitute major differences
in RGP among seedlings even of the same species (Landis & Skakel 1988). Seedlings
with large robust root systems have the best opportunity to achieve early competitive
position (Ruehle and Kormanik 1986). Although a robust root system is normally
associated with desirable stem characteristics, large stems themselves are not
necessarily related to robust roots and competitive ability after outplanting (Feret &
Kreb 1986).


7


Figure 4. Monthly diameter growth of Gmelina as affected by provenances, planting
distance and root classes.

The interaction effects of F x D consistently significant up to the 12th month. F
x R and D x R interactions were not significant up to the 4th month but significant on
the 5th month. There interactions became insignificant in the 6th month but significant
result reappears again on the 7th up to 12th month.
The interaction effect of the distance of planting x root classes (D x R) is
significant on the 8th to 10th months but in the rest of the months there was no
significant differences.
The number of FOLR has been shown to be positively related to seedling
competitiveness both in the nursery and after outplanting and has been a highly
heritable trait with some species (Kormanik 1986b, Kormanik et al. 1990).
Analysis of variance reported a significant result of dbh of Gmelina after one
year in the field in terms of provenance and root classes. However, distance of planting
is insignificantly different in dbh. Cotabato and Quezon provenances were
significantly different from Davao del Sur.
The root classes on the other hand reported that root class 3 is significantly
different with root classes 1 and 2 (Table 1). RGP is found to affect seedling
morphology as well as physiology ( Cannell et al. 1990) in their research which indicated
that high sturdiness ratio, root:shoot ratio, root collar diameter, root lengths and
volumes which have been traditionally associated with high seedling stock quality
apparently gave high RGPs.

8


Table 1. Means1 of dbh, merchantable height and total height as influenced by
provenance.
Provenances

dbh

Merchantable
height

Total
height

Davao del Sur
Candelaria, Quezon
Cotabato Province

4.19516854a
6.62504505a
6.84514851a

2.39460674a
3.45414414b
2.76594059c

3.86146067a
5.26441441b
4.68742574a

Planting distance
2x2m
2x3m
2x4m

5.86547368a
5.91300000a
6.14707547a

2.84189474a
2.76880000a
3.10405660a

4.53031579a
4.55240000a
4.86632075a

Root classes
0 -10
11-20
21-30 & up

5.91138298a
5.91467290a
6.11570000b

3.04925532a
2.85000000a
2.84310000a

4.77436170a
4.57271028b
4.63380000b

1

Means with the same letter are not significantly different at 5% level of significance.

These results indicated that RGP is a superior measure of seedling quality as
compared to standard morphological traits used before (Feret & Kreh 1985). But this
does not mean that other morphological attributes are not important for maintaining
seedling quality, rather the difference in physiological quality can cause more variation
in RGP than the morphological characteristics by which seedlings are currently being
graded (Larsen et al. 1983). Stone et al. (1962) pointed out that there were physiological
differences in seedling grown from the same or different nursery. Hence, it was further
suggested that physiological grade of seedlings should be evaluated vis a vis other
seedling quality information (Landis & Skakel 1988).
The interaction effects of all factors were found insignificantly different in terms
of dbh growth of Gmelina trees in the field.
Basal area. The Gmelina trees differed significantly in basal area growth in terms of
provenance and distance of planting while root classes and interactions of all factors
were found insignificant. Quezon and Cotabato were significantly different with Davao
del Sur provenance (Table 2). The 2 x 2 m tree spacing was significantly higher with
2 x 3 m and 2 x 4 m tree spacing.
Stem diameter according to Dey and Parker (1997) is a best predictor of growth.
Computation of the basal area considered the density of tree per hectare, does more
density of tree means higher basal area. Interactions of all factors were insignificantly
affects the basal area of the tree in tons/ha.
Tree volume. Tree volume reported an insignificant result in terms of provenance,
but significant on distance of planting and root classes. The 2 x 2m tree spacing was
significantly higher in volume compared to the other two planting distances (Table
3). This is true because the computation is per hectare basis so that stand density is


9

Table 2. Means1 of basal area (m2/ha) as influenced by the three factors: provenances,
distance planting and root classes.
Provenances Means

Davao del Sur 10.0796935a
Quezon
25.0388559b
Cotabato
24.9222823b
1

Distance of
Planting
2 x2m
2x3m
2x4m

Means

27.6022816a
19.7542062b
15.0558384c

Root
classes

Means

0-10
19.4923923a
11-20
20.6161062a
21-30+ 21.5534801a

Means with the same letter are not significantly different at 5% level of significance.

Table 3. Means1 of volume (cu.m/ha) as influenced by the three factors: provenances,
distance planting and root classes.
Provenances Means

Davao del Sur 0.66064842a
Quezon
1.30257138a
Cotabato
0.84223270a
1

Distance of
Planting
2 x2m
2 x3m
2x4m

Means

1.29193174a
0.83650665b
0.77419298c

Root
classes

Means

0-10
0.92724126b
11-20
0.92475517b
21-30+ 1.02952880a

Means followed by the same letter vertically per factor are not significantly different at P>F.

considered. More tree stand is found on closer spacing; does volume on 2 x 2m tree
spacing is obviously higher as compared with the wider spacing. However, this
finding is acceptable only at one year old Gmelina plantation. Root classes on the
other hand, reported root class 3 as significantly higher with root class 2 and 1.
Interactions of all factors were found insignificantly different on tree volume.
Biomass. The analysis of variance for the estimated above ground, root and total
tree biomass showed a significant result on all parameter considered. Cotabato and
Quezon provenances were significantly higher with Davao del Sur in terms of above
ground and root biomass. However, for the total tree biomass, provenance from
Cotabato was significantly higher as compared with the other two provenances which
are insignificant to each other (Table 4). Interactions of the three factors reported no
significant differences in all parameters estimated.
This finding can be explained by the positive and significant correlation of
provenance with heights and biomass of one year old Gmelina. In this study, height
and biomass can be viewed as highly influenced by provenance. Experiment of Ruehle
and Kormanik (1986) with northern red oak showed that within a family, desirable
stem characteristics of half-sib progenies were consistently associated with large
numbers of FOLR. Frequency distributions of seedlings from three white oak mother
trees were similar when seedling populations were stratified by FOLR with diameter
greater than or equal to 1mm at the proximal end (Kormanik, Ruehle & Muse 1989a).

10


They further concluded that the root collar diameter, height and top and root weights
of trees increased from the lowest lateral roots class (0 – 3 roots) to the highest class
(>21 roots). In loblolly pine, the same group of scientists computed the frequency
distributions and heritability of FOLR for seedlings progenies of 37 mother trees
(Kormanik, Ruehle & Muse 1986b). Their findings indicated significant differences in
all measured seedling parameters from the smallest to the largest FOLR class. If the
frequency distribution of seedlings with strong root systems is genetically controlled
and if strong root systems are excellent indicators of field performance as evidenced
in the above mentioned studies, tree breeders may have several important implications
(Carandang 1994). It maybe necessary, for instance, to change the ways in which
individual seedlings are selected for progeny tests. It may also possible to removed
one source of variation from tests by using only the progeny that has a satisfactory
lateral root development, and it maybe desirable to select trees that produce high
proportions of progeny with superior root systems.

Table 4. Means1 of AGB (tons/ha), root biomass (tons/ha) and total tree biomass
(tons/ha) as influenced by provenance, distance of planting and root classes.
Provenances

AGB

Root
Biomass

Total Tree
Biomass

Davao del Sur
Quezon
Cotabato Province

1.86651719a
5.07619071b
5.12120667b

0.64214383a
1.56790656b
1.55668264b

2.50866102a
6.31966747b
6.66614853c

Planting distance
2 x2m
2 x3m
2 x4m

5.55108295a
3.96281552b
3.04891170c

1.73137664a
1.23963333b
0.94310625c

7.28245959a
4.83047358b
3.99201795c

Root classes
0-10
10-20
21-30+

3.89959370a
4.15148312b
4.36048570b

1.22383184a
1.29280048b
1.35043533b

5.00605289a
5.31592612b
5.58661856b

1

Means followed by the same letter vertically per factor treatment are not significantly
different at P>F

In terms of distance of planting, the 2 x 2 m tree spacing was significantly higher
compared to the two other spacing arrangements (Table 9). 2 x 3 m as well is significantly
different with 2 x 4 m in all parameters computed. Lauridsen and Kjaer (2002) reported
that the total standing biomass (kg/ha) and productivity of G. arborea at spacing
2 x 2 m was higher compared to 3 x 3 m plant spacing.
For the root class, it was found that root class 3 is consistently higher and
significantly different compared to root class 1 but not to root class 2 (Table 9).


11

Interactions of the different factors were observed to be insignificant in all parameters
computed.
Family mean heritability estimates. Narrow sense heritability estimate is used for
the growth trait of Gmelina after one year in the field. All traits were found relatively
high. From Figure 5, highest genetic control appears to be in Root Biomass (h2 =
0.998) followed by merchantable height (h2 = 0.997), basal area (h2 = 0.982), above
ground biomass (h2 = 0.979), total tree biomass (h2 = 0.970), volume (h2 = 0.784) and
the lowest is DBH (h2 = 0.767). The mean square values used in the computation of
the respective heritability values of seedling traits is in Appendix Table 37 to Appendix
Table 45.
Tree height in the field trials reported to be highly controlled genetically than
dbh (Figure 2). This finding confirms that genetically determined variation exists in
root system of plants (Street 1957). Brisette (1990) recognized that genetics plays a
critical role in determining root system development of forest trees, both in the nursery
and in outplanting. The number of FOLR has been shown to be positively related to
seedling competitiveness both in the nursery and after outplanting and has been a
highly heritable trait with some species (Kormanik 1986b, Kormanik et al. 1990).

Heritabilty Estimate

1
0.8
0.6
0.4
0.2
0
DBH MH

TH

BA

Volu
RB AGB
me

TB

Heritabilty 0.767 0.987 0.852 0.982 0.784 0.998 0.979 0.97

Tree Growth

Figure 5. Family mean heritability of Gmelina from 3 provinces in the Philippines
after 1 year in the field.

12


Kormanik (1986) contended that while stem diameter maybe considered a better
estimator of seedling vigor, it cannot explain many of the differences in seedling
performance after outplanting. Webb (1969) earlier cautioned against using stem
diameter when comparing early plantation performance of sweetgum seedlings from
the same family if they are grown in different seedling bed densities. This is because
of the fact that stem diameter represents a seedling’s response to edaphic conditions.
Nursery cultural conditions such as seedling bed density, fertility, moisture and
mycorrhizal conditions have been shown to affect stem diameter. Unfortunately, the
edaphic conditions that stimulate stem diameter increases are not found in the field.
Kormanik’s study on sweetgum revealed that the distributions of seedlings among
root grades remained relatively constant within an open pollinated mother tree seedlot.
This finding led to his recommendation that seedling grading based on lateral root
morphology maybe a practical way to identify the seedlings with the best potential
(Carandang 1994).
Regression and Correlation analysis. The effect of provenance and distance of
planting on RGP of Gmelina had been determined through regression and correlation
analysis of RGP in terms of root classes and root biomass across tree growth
performance as affected by various factors considered in the study. Provenance of
Gmelina tree revealed significant relationship with merchantable height, basal area,
roots, above ground and total tree biomass (Table 5).
With the exemption of dbh and volume, provenance has significant regression
in most tree characteristics. This is supported by the positive and significant
relationship of provenance with heights, basal area, agb, root and total tree biomass
(Table 5). Distance of planting did not show significant regression with all tree
characters measured. This result is supported by the poor relationship of distance of
planting with all tree characters considered in the study. Dbh, basal area, root and
total tree biomass revealed significant relationship with root classes (Figure 6) while,
all parameters measured were significantly related with root biomass (Table 6).
Thompson and Schultz (1995) found a negative correlation between initial height
and first-year growth of northern red oak (Quercus rubra L.), while the number of
FOLR was positively and significantly correlated with height, diameter growth, and
survival. In contrast, initial height of Konara oak (Quercus serrata Thunb.) in Japan
was positively associated with survival and weight after 5 years (Matsuda 1989).
Data from Jacobs and Siefert (undated) indicated that FOLR was poor predictor of
height and diameter growth of Northern red oak, white oak, and black cherry (Primus
serotina Ehrh.) after one year.
Stem diameter, shoot length, and number of FOLR were correlated with second
year height and diameter of Northern red oak 2 years after planting in Ontario, with
initial stem diameter being the best predictor (Dey & Parker 1997). Stem diameter was
also a good predictor of many root system traits such as volume, area and dry mass.
This is consistent with the study of Williams (1972) that showed stem diameter
as better predictor of black walnut growth than root fibrosity. In the sweetgum research
of Belanger and Mc Alpine (1975), stated that the growth response of various root


13


Figure 6. Path correlation analysis (Pearson’s) across RGP, DBH, AGB, heights and
biomass.
collar diameter grades was obvious after the first growing season and continued
through the seventh season.
As revealed in the correlation analysis, the root classes are likewise correlated
significantly with basal area, biomass and dbh.
Root biomass on the other hand, showed a significant regression with all
variables considered in the study (Table 6). Figure 6 presents a correlation path
analysis across all traits of tree growth.
As a measure of root growth potential (Stone & Schubert 1959, Burdett 1979),
the number of lateral roots is now finding wide use in physiological grading of forest
nursery seedling stocks.
The results of the analysis indicated that the RGP in terms of root class and root
biomass of Gmelina tree was positively associated with the other growth traits and
characters. Similar to the result of this study, Thompson and Schultz, (1995) found
that the number of FOLR was positively and significantly correlated with diameter
growth, heights and growth of trees such as basal area and volumes.
It can be said therefore that the use of RGP as an expression of seedling quality
finds merit in its positive correlations with the other growth traits considered in the
study. All morphological features specifically height and stem diameter, currently
provide the best estimate of seedling performance after outplanting (Mexal and Landis
1990). Diameter is considered to be one of the best predictor of field survival while

14


height seems to predict height growth in plantation (Ritchie 1984). Root classes are
highly correlated with biomass production as the findings of this study indicate
support to Mexal and Landis (1990). Nevertheless, root morphology, specifically
number of FOLR, finds much use with the trend towards the use of root growth
potential as an indicator of early field performance and subsequent growth (Larsen et
al. 1986, Ritchie & Dunlap 1980).
The positive correlation of root classes with stem and growth characters was
found to be highly significant in this study. Operational experiences tended to indicate
that, other factors being equal seedlings with large stem calipers or diameters
outperform those with smaller ones (Chavasse 1990, Cleary et al. 1979, Sutton 1979).
When seedlings were carefully lifted as what has been done in the study, stem
diameter were closely related with number of FOLR. At harvest, large diameter seedlings
have more primary laterals (Rowan 1986). While it is possible that large diameter
seedlings inherently have a more fibrous root system, it is more likely that smaller
seedlings have thinner primary lateral roots that are more easily stripped during
lifting operations (Carandang 1994). The improved field performance ascribed to
larger diameter may partially, be the result of decreased root stripping. Blake et al.
(1989) found that the relationship between field survival and seedling diameter was
also affected by root mass especially for smaller diameter seedlings. Seedlings with
good root mass consistently survived better than those with poor root mass. The
positive correlation of root classes with stem diameter and seedling height has some
physiological basis too. Evidences from the works of Richardson (1957, 1958) point
to the fact that lateral root initiation and growth are influenced by both nutritional
and hormonal factors derived from the shoot.

SUMMARY AND CONCLUSION
Performance of Gmelina in the field for one year showed strong genetic control
over height, basal area, and biomass. The seeds from Quezon were significantly
different in terms of merchantable and total height compared to Cotabato and Davao
del Sur seed sources. Quezon and Cotabato seed sources did not differ significantly
on basal area and biomass.
Distance of planting insignificantly affects heights, diameter growth and survival
rate of the trees. However, basal area, tree volume and biomass varied significantly.
Two x 2 m tree spacing was significantly different with 2 x 3 m and 2 x 4 m.
Root classes on the other hand, affected diameter, heights, percent survival,
and volume significantly. Root class 3 is significantly differs with root classes 2 and
1 in terms of dbh. However, root class 3 did not show significant variation with root
class 2 in terms of total tree height and volume. The three factors did not show
variations on basal area, and merchantable height. Root classes was found to be
positively and significantly correlated with dbh, basal area and root biomass.

RECOMMENDATIONS
A similar study should be undertaken to validate the result of this study. It was
revealed in this study that variations in root and stem characteristics exist among the


15

three provenances of G. arborea. A study should be conducted to determine if such
variations will be evident also among the other sources of seeds of the species. Only
Cotabato province has two locations considered in this study. Continuous gathering
of data should be made to validate if the findings of this study is true in the long run.
Effort should be put into identifying provenances that perform well in many trials
rather than only in one or in a few.
Kabacan, Cotabato and Candelaria Quezon seed sources of G. arborea is
recommended for plantation in particular place in Arakan, Matalam, Cotabato.

ACKNOWLEDGMENTS
This work was funded by the Commission on Higher Education (CHED), Quezon City
through Faculty Development Program and the Cotabato Foundation College of Science and
Technology. The authors wish to thank the following: (a) Dr. Makalutang B. Luna, President
of the Cotabato Foundation College of Science and Technology for his encouragement;(b) the
family members of the first author: Ina and Papa, brother and sister, his loving wife and kids
and (c) above all to most merciful and most beneficent Allah who made this work possible.

LITERATURE CITED
Belanger, R.P. and E.R.B. McAlpine. 1975. Survival and early growth of planted sweetgum
related to root-collar diameter. Tree Planters’ Notes 26: 1-21.
Burdett, A.N. 1979. New methods of measuring root growth capacity: their value in assessing
Lodgepole stock quality, Canadian Journal of Forest research. 9: 63: 67.
Burdett, A.N. 1987. Understanding root growth capacity, theoretical considerations in
assessing planting stock quality by means of root growth tests. Canadian Journal of Forest
Research. 17: 768- 775.
Cannel, M.G.R, D.M. Tabbush, J.D. Deans, M.K. Hollingsworth, L.J. Shippard, J.J. Philipson
and M.B. Murray. 1990. Sitka spruce and Douglas-fir seedlings in the nursery and in cold
storage: root growth potential, carbohydrate content, dormancy, frost hardiness and mitotic
index. Forestry 63(1): 9-27.
Carandang, W.M. 1994. Lateral root development and seedling performance of large leaf
mahogany (Swietenia macrophylla King). Ph.D Thesis, University of the Philippines Los
Banos, College, Laguna. (unpublished)
Chavasse, C.G.R. 1978. The root form and stability of planted trees with special reference to
nursery and establishment practices. British Columbia Ministry of Forest /Canadian Forest
Service Department Report 8.
Chavasse, C.G.R. 1990. Planting stock quality. A review of factors affecting performance.
New Zealand Journal of Forestry 25: 144-171.
Cleary, B.D., R.D. Greaves and R.K. Hermann. 1979. Regenerating Oregon’s Forests. Oregon
State University Extension Center, Corvallis, Oregon, USA.
Coutts, M.P. and G.J. Lewis. 1983. When is the structural root system determined in Sitka
spruce? Plant and Soil 71: 155-160.
Deans, J.D. and E.D. Ford. 1983. Seasonal pattern of radial growth and starch dynamics in
plantation-grown Sitka spruce trees of different ages. Institute of Terrestial Ecology,
Bush Estate Penecuik, Midlothian, Scotland, EH 26 OQB.
Deans, J.D., C. Lundberg, M.G.R. Cannel, M.B. Murray and L.J. Sheppard. 1990. Root
system fibrosity of Sitka spruce transplants: relationship with root growth potential.
Forestry 63(1): 1-7.

16


Dey, D.C. and W.C. Parker. 1995. Morphological indicators of stock quality and field
performance of red oak (Quercus rubra L.) seedlings underplanted in a central Ontario
shelterwood. New Forests 14: 145-156.
Duryea, M.L. and K.M McClain 1984. Altering seedling physiology to improve reforestation
success. In: Huryea and Brown (eds). Seedling Physiology and Reforestation Success.
Martinus Nijhoff/Dr. W. Junk Publishers, The Hague, Netherlands.
van. Eerden, E. and J.M. Kinghorn. 1978. Proceedings of the Symposium on Root form of
planted trees. BC Min. Forest/Canada Forest Service. Report No. 8, Prov. British Columbia,
Min. Forest, Victoria, British Columbia, Canada, 357 p.
Feret, D.D. and R.E. Kreb. 1985. Seedling root growth potential as an indicator of loblolly
pine field performance. Forest Science 31(4): 1005-1011.
Gazal, R.M. 1998. Effect of soil moisture and root growth potential of narra (Pterocarpus
indicus Willd.) transplants. M.Sc. Thesis, University of the Philippines Los Banos, College,
Laguna. (unpublished)
Hasase, D.L. and R. Rose. 1994. Root volume and growth of Ponderosa pine and Douglasfir seedlings. A summary of the eight growing season. Western Journal of Applied
Forestry12(3): 69-73.
Hashizume, H. and H. Han.1993. A study on reforestation using large-size Quercus acutissima
seedlings. Hardwood Research 7: 1-22.
Hawkins, C.B.D. and W.D. Binder.1990. State of the art seedling stock quality tests based on
seedling physiology, pp. 19-21. In: Rose, R., S.J. Campbell and T.D. Landis (Eds.). Target
Seedling Symposium: Proceedings, combined meeting of the Western Forest Nursery
Associations; 1990 August 13-17; Roseburg, OR. Fort Collins (CO): USDA Forest Service,
Rocky Mountain Forest range Experiment Station. General Technical Report RM-200.
Kormanik, P.P. 1986. Lateral root morphology as an expression of sweetgum seedling quality.
Forest Science 32(3): 595-604.
Kormanik, P.P. and H.D. Muse. 1986. Lateral roots: a potential indicator of nursery seedling
quality. TAPPI, 28 September 01- October 1986.
Kormanik, P.P., J.L. Ruehle and H.D. Muse. 1989. Frequency distribution of lateral roots of
1-0 barsroot white oak seedlings. Research Note SE-353, USDA Forest Service, Southeastern
Forest Experiment Station, USA.
Kormanik, P.P., J.L. Ruehle and H.D. Muse. 1990. Frequency distribution and heritability of
first-order lateral roots in lobloly pine seedlings. Forest Science 36(3): 802-814.
Landis, T.D. and S.G. Skakel. 1988. Root growth potential as an indicator of outplanting
performance: Problems and perspective. Proceedings, combine meeting of the western
Forest Nursery Association; Western Forest Nursery Council; Forest Nursery Association
of British Columbia; and international Forest Nursery Association. 8-11 August. Vernom,
British Columbia, Canada.
Larsen, H.S., D.B. South and J.M. Boyer. 1986. Root growth potential, seedling morphology
and bud dormancy correlates with survival of Loblolly pine seedlings planted in December
in Alabama, Tree Physiology 1: 253-263.
Lauridsen, E.B. and E.D. Kjaer 2002. Site index equation for smallholder plantations of
Gmelina arborea in Leyte Province, the Philippines. Small-scale Forestry Journal
7(1): 87-93, March 2008, Springfield, Netherlands.
Matsuda, K. 1989. Survival and growth of konara oak (Quercus serrata Thunb) seedlings in
an abandoned coppice forest. Ecological Restoration 4: 309-321.
McCreary, D.D. and M.L. Duryea. 1987. Predicting field performance of Douglas-fir seedlings:
Comparison of root growth potential, vigor, and plant moisture stress. New Forests
1: 153-169.


17

Mexal, J.G. and T.D. Landis. 1990. Target seedling concepts; height and diameter. pp. 77-36.
In: Rose, R., S.J. Campbell and T.D. Landis (Eds.). Proceediungsof the Target Seedling
Symposium, Combine meeting of the Western Forest Nursery Associations, August 13-17,
1990. Roseburg, Oregon USDA Forest Service. Rocky Mountain Forest and range Exp. Sta.
Gen. Technical Report RM 200, USA.
Ritchie, G.A. 1984. Assessing seedling quality, pp. 243-260. In: Duryea, M.L. and T.D.
Landis. (Eds.). Forest nursery manual: Production of bare root seedlings. Martinus Nijhoff/
Dr. W. Junk Publishers, Boston, MA, USA.
Ritchie, G.A. 1985. Root growth potential principles, procedures and predictive ability. In:
Duryea, M.L. (Ed.). Evaluating seedling quality: principle, procedures and predictive abilities
of major tests. 93 -104. College of Forestry, Oregon State University, Corvallis, Oregon,
USA, October 16-18, 1984.
Ritchie, G.A. and J.R. Dunlap 1980. Root growth potential: Its development and expression
in forest tree seedlings. New Zealand Journal of For. Sci. 10: 218-248
Ritchie, G.A., Y. Tanaka, R. Meade and S.D. Duke. 1993. Field survival and early height
growth of Douglas-fir rooted cuttings: relationship to stem diameter and root system quality.
Forest Ecology and Management 60: 237-256.
Rook, D.A. 1971. Effect of undercutting and wrenching on growth of Pinus radiata Don
seedlings.The Journal of Applied Ecology, 1971-JSTOR
Rose, R., M. Atkinson, J. Gleason and T. Sabin, 1991. Root volume as agrading criterion to
improve field performance of Douglas-fir seedlings. New Forests 9: 195-209.
Rowan, S.J. 1986. Seedbed density affects performance of slash and loblolly pines in Georgia.
In: South, D.B (Ed.) International Symposium on nursery management practices for the
southern pines. Alabama Agricultural. Station, Auburn University, Auburn, Alabama, USA.
Ruehle, J.L and P.P. Kormanik. 1986. Lateral root morphology: a potential indicator of
seedling quality in northern red oak. Asheville (NC): USDA Forest Service, Southeastern
Forest Experiment Station. Research Note SE-344, 6 p.
Simpson, D.G.. and G.A. Ritchie. 1996. Does RGP predict field performance? A debate. New
Forests 13: 249-273
Sharpe, A.L. and W.L. Mason. 1992. Some methods of cold storage can seriously affect root
growth potential and root moisture content Forestry 1992 - Inst. Chartered Foresters.
Stone, E.C. and G.H. Schubert. 1959. Root regeneration by Ponderosa pine seedlings, lifted at
different time of the year. Forestry Science 5: 322 -332.
Stone, E.C., J.L. Jekinson and S.L. Krugman. 1962. Root regenerating potential of Douglasfir seelings lifted at different times of the year. Forest Science 8: 288-297.
Sutton, R.F. 1979. Planting stock quality and Grading. Forest Ecology and Management
2: 123-132.
Thompson, J.R. and R.C. Schultz. 1995. Root system morphology of Quercus rubra L.
planting stock and 3-year field performance in Iowa. New Forests 9: 225-236.
Webb, C.D. 1969. Uniform seedling density is important in hardwood progeny test nurseries.
In: Proceeedings of the 10th Southern Conference on Forest Tree Improvement, 17-19 June
1969, Houston, Texas, USA.
Williams, R.D. 1972. Root fibrosity proves significant in survival, growth of black walnut
seedlings. Tree Planters’ Notes 23: 22-25.

Beyond Excellence ©
18

ASIA LIFE SCIENCES

Effect of root growth potential, planting distance and provenance of Gmelina arborea

Recommended

Recommended

More Related Content

What's hot

What's hot (19)

Similar to Effect of root growth potential, planting distance and provenance of Gmelina arborea

Similar to Effect of root growth potential, planting distance and provenance of Gmelina arborea (20)

Recently uploaded

Recently uploaded (20)

Effect of root growth potential, planting distance and provenance of Gmelina arborea