Abstract:

This study was conducted in the nursery of the Faculty of Forestry, University of
Khartoum, Shambat, from 3/8/2006 to 22/11/2006. It aimed to investigate the effects
of four container sizes (8x13, 10x20, 20x30 and 30x40 cm) and four types of growing
media (sand, clay, silt and humus) on the growth of three tree species (Tamarindus
indica, Albizia lebbeck and Acacia senegal).
The results revealed that the growth of Tamarindus indica seedlings was generally
highest in the clay substrate and lowest in the humus medium, and it was moderate in
the silt and sand substrates. The growth of shoot length was in the following
sequence: clay (72.8 cm), silt (56.2 cm), humus (53.9 cm) and sand (36.3 cm). The
root length growth was in the following sequence: sand (73.3 cm), silt (56.6 cm), clay
(49.3 cm) and humus (23.2 cm). The root collar diameter growth was in the following
sequence: Clay (7.2 mm), silt (5 mm), sand (4.8 mm) and humus (4.2 mm). The
seedling weight growth was in the following sequence: clay (15.5 g), sand (7.5 g), silt
(6.9 g) and humus (4.3 g).
The growth performance of T. indica seedlings was proportional to the container
size i.e. the highest values of growth parameters were found in the bigger containers
(30x40 and 20x30 cm) and the lowest values were in the smaller containers (8x13 and
10x20 cm). The mean shoot lengths were in the following order from the bigger
container to the smaller container: 68.8, 60.9, 44.6 and 41.1 cm. The mean root
lengths were in the following order from the bigger container to the smaller container:
68.5, 51.2, 42.9 and 47.7 cm. The mean root collar diameters were in the following
order from the bigger container to the smaller container: 6.4, 5.7, 4.6 and 4.4 mm. The
mean of the seedling weights were in the following order from the bigger container to
the smaller container: 13.3, 10, 5.3 and 5.8 g.
The results revealed that the growth of Albizia lebbeck seedlings was generally
highest in the silt substrate and poorest in the sand medium, and it was moderate in
the clay and humus substrates. The growth in shoot length was in the following
sequence: silt (73.3 cm), clay (62.6 cm), humus (56.4 cm) and sand (36.8 cm). The
root length growth was in the following sequence: silt (57.1 cm), sand (55.9 cm), clay
(29.5 cm) and humus (25.9 cm). The root collar diameter growth was in the following
sequence: silt (9.9 mm), clay (8.9 mm), humus (8.2 mm) and sand (7.3 mm). The
seedling weight growth was in the following sequence: silt (36.8 g), clay (29.2 g),
humus (21.8 g) and sand (18.3 g).
The growth performance of Albizia lebbeck seedlings was proportional to the
container size i.e. the highest values of growth parameters were found in the bigger
containers (30x40 and 20x30 cm) and the lowest values were in the smaller containers
(8x13 and 10x20 cm). The mean shoot lengths were in the following order from the
bigger container to smaller container: 70.4 cm, 60.4 cm, 50.2 cm, and 41.3 cm. The
mean root lengths were in the following order from the bigger container to the smaller
container: 50.4, 39.6, 49.5 and 31.4 cm. The mean root collar diameters were in the
following order from the bigger container to the smaller container: 10.1, 9.6, 7.5 and
6.5 mm. The mean of the seedling weights were in the following order from the
bigger container to the smaller container: 41.4, 30.6, 19.1 and 10.7 g.
XV
The results revealed that the growth of Acacia senegal seedlings was generally
highest in the clay substrate and poorest in the humus medium, and it was moderate in
the silt and sand substrates. The growth in shoot length was in the following
sequence: Clay (61.2 cm), silt (49.1 cm), humus (45.6 cm) and sand (41.4 cm). The
root length growth was in the following sequence: Clay (48.8 cm), sand (48.7 cm), silt
(48.5 cm) and humus (27.7 cm). The root collar diameter growth was in the following
sequence: Clay (7.4 mm), silt (4.8 mm), sand (4.8 mm) and humus (4.4 mm). The
seedling weight growth was in the following sequence: Clay (10.3 g), sand (4.4 g), silt
(3.9 g) and humus (3 g).
The growth performance of Acacia senegal seedlings was proportional to the
container size i.e. the highest values of growth parameters were found in the bigger
containers (30x40 and 20x30 cm) and the lowest values were in the smaller containers
(8x13 and 10x20 cm). The mean shoot lengths were in the following order from the
bigger container to the smaller container: 57.7 cm, 53.8 cm, 43.2 cm, and 40.6 cm.
The mean root lengths were in the following order from the bigger container to the
smaller container: 56.6, 54.3, 31.5 and 41.7 cm. The mean root collar diameters were
in the following order from the bigger container to the smaller container: 6, 5.6, 5.1
and 4.5 mm. The mean of the seedling weights were in the following order from the
bigger container to the smaller container: 7.5, 6.5, 4 and 3 g.
The growth performance of all the measured parameters, without consideration to
the media type and tree species, increased when the size of the container increased,
i.e. the highest values of parameters growth were found in the bigger containers
(30x40 and 20x30 cm) and the lowest values were in the smaller containers (8x13 and
10x20 cm). The mean shoot lengths were in the following order from the bigger
container to the smaller container: 65.7, 58, 44.9, and 42.3 cm. The mean root lengths
were in the following order from the bigger container to the smaller container: 58.3
cm, 45.5 cm, 41.5 cm, and 41 cm. The mean root collar diameters were in the
following order from bigger container to the smaller container: 7.6, 6.8, 5.8 and 5.1
mm. The mean seedling weights were in the following order from the bigger container
to the smaller container: 21.2, 14.8, 9.5 and 6.3 g.
All the measured parameters, without consideration to the container sizes and tree
species, were generally greater in the clay than in the other media. The growth of the
shoot length was in the following sequence: Clay (65.7 cm), silt (59.2 cm), humus (52
cm) and sand (38 cm). The root length growth was in the following sequence: Sand
(60 cm), silt (53.8 cm), clay (43.5 cm) and humus (25.6 cm). The root collar diameter
growth was in the following sequence: Clay (7.8 mm), silt (6.5 mm), humus (5.6 mm)
and sand (5.6 mm). The seedling weight growth was in the following sequence: Clay
(17.6 g), silt (15.6 g), sand (10.1 g) and humus (9.7 g).
A. lebbeck seedlings recorded the highest growth than the other two species. T.
indica seedlings came in the second degree and A. senegal seedlings came in the last
degree.
Finally the results showed that larger containers permit to obtain bigger and sturdy
seedlings for all the tree species. Clay represents a good potential medium for raising
T. indica and A. senegal seedlings while silt medium is suitable for raising A. lebbeck
seedlings in the nursery. 