Note: Descriptions are shown in the official language in which they were submitted.
~'25~97~
-- 1 --
The present invention relates to a container
~or growing and subsequent transplanting of seedlings,
more specifically although not exclusively for growing and
plan~lng of tree seedlings.
In accordance with the invention there is
provided a container for growiny and subsequently
transplanting of seedlings comprising a moulded plastic
tray with a horizontal upper side formed with a series of
cavities composed by a series of closely-packed upper
openings which at least at the uppermost portions thereof
are uniformly regularly hexagonal and which are bounded by
substantially vertical walls defining a honeycomb
formation said upper openings continuing in lower openings
which taper downwardly and are substantially circular in
cross section, the walls bounding said tapering openings
forming shells distinct from the shells of adjacent
cavities. Preferably, the taper of said tapering openings
is the least that allows the harmless removal of the plugs
of growth medium from the cavities to~ether with the grown
seedlings. Such taper provides maximu~. volume for each
cavit~.
The arrangement has numerous advantages over
prior seedlings containers of the kind referred to.
The main advantage is that the effective volume
of the cavities as related to the total volume of the
container is maximized while taking into account all the
requirements which have to be fulfilled for creating a
container suitable for growing and transplanting of tree
seedlings.
Such a container should for instance have a
rigidity sufficient for handling the container when
transported or used for the transplantation, preferably
suspended in a holder carried by the plan~er. It should
further be light in weight and as inexpensive as possible.
A still further reguirement is that several containers can
be stacked upon each other in a space-...................
77
saving manner and of co~rse the plugs of growth medium
with the grown seedlings have to be easy to remove from
the cavities.
For instance- as compared with containers of
similar size formed with circular openings, the present
container exposes a larger surface area of the soil or
other growing medium when Eilled into the cavities,
providing for better aeration of the growing medium, and
also facilitating the application of treatment liquids
such as fertilizers, fungicides, pesticides etc. The risk
for formation of moss at the upper side of the container
is also minimized due to the minor exposed upper surface.
It has been found that the present arrangement
results in seedlings growing to a larger stem diameter at
equal seedling heights. It is suggested that this is
because of the larger volume of the cavity especially in
the upper portion thereof. It is known that the stem
diameter at the time of planting is an important indicator
o the survivability of the seedling.
Other advantages of the present arrangement will
become apparent from the following detailed description,
with reference to the accompanying drawings, which show by
way of example one form of container in accordance with
the invention.
In the accompanying drawings:
Figure 1 shows a plan view of a container in
accordance with the invention;
Figure 2 shows a vertical cross-section through
a cavity of the container taken on the line 11-11 in
figure 1;
Figure 3 shows a vertical section through a
cavity of the container, taken on the line 111-111 in
figure 1;
Figure 4 shows a partial plan view of the
container of figure 1.
- 2 -
J~77
The illustrated container 1 consists of a
single piece moulding of plastics having an upper~ planar
wall 2. This planar wall is interrupted by a series of
closely-packed cavities generally designated as 3. Each
cavity comprises -as can be seen in figures 2-4 inclusive-
an upper opening 4 having a hexagonal cross section. This
upper opening 4 is bounded by substantially vertical walls
5 having a height of at least 1/4 of the total height of
each cavity. As can be seen these walls are relatively
thin and form a honeycomb formation where each of the
cavities has one vertical wall 5 thereof integral with a
vertical wall of an adjacent cavity. The hexagons are
regular and the openings are uniform in size. As best
seen in figure 4 each hexagonal opening is bordered by an
upper thin edge of the side walls 5. Each upper opening
continues in a lower opening 6 which tapers downwardly and
is circular in cross section. This lower opening is
bounded by a tapering side wall 7 which extends upwardly
in upwardly peaked portions 8 to the vertices of the
hexagonal opening ~ adjacent the upper side of the
container. Thus, on either side of the peaked portions 8
the vertical side walls 5 merge with the conical side wall
7 along parabolas 9, of which the vertical axes coincide
with the midpoints of the sides of the hexagon. The lower
opening 6 terminates in a more steeply inwardly inclined
conical frustum 10 bounded by a side wall 11 and said
conical frustum terminates at a circular opening 12.
Thus, each cavity will have a first section which is
hexagonal in cross section, a second section bounded by
alternating planar and curved surfaces and a third section
in the shape of a circular and tapering surface
terminating in a more steeply inwardly inclined conical
surface ending in a cylindrical opening.
In order to facilitate the stacking of the
containers a number of ribs 13 (see figs. 3 and 4) are
-- 3 --
~5 1;.~ . . : `' `
~:5~3~7~
provided. Said ribs bridge the distance between two
adjacent conical side walls 7, and provide support
surfaces 13a enabling a series of containers to be stacked
one on another with the upper ends of walls 5 of each
lower container enga~ing the sur~aces 13a of the container
thereabove.
In order to deter the growth of roots in a
transverse direction, which would tend to encircle and
eventually strangulate the roots, preferably the inner
side of the side wall of each cavity 3 is formed with a
series of downwardly extending raised ribs 14 which serve
to guide the root growth. Desirably, these extend down-
wardly from each vertex of the hexagon adjacent its upper
side, as shown.
The planar portion ~ has a downwardly-turned
lip or rim 15 which as seen in fig. 1 extends along each
short side of the container and also extends around the
corners to meet the walls 5 of the outermost cavlties.
This lip or rim 15 increases the rigidity of
the container and the ribs 13 and 14 also add rigidity ~o
the container which owing to the relatively high vertical
walls 5 forming the honeycomb structure in itself has a
considerable rigidity allowing the container fully loaded
with growing medium and seedlings to be carried by hand or
carried by a planter using a holder which may comprise a
rail connected to a belly-strap whereas a strap attached
to the side of the container which is most remote from the
planter is worn by the planter for instance over his
shoulders. A plurality of holes 16 arranged in the long
upper sides of the container serve to releasably connect
the container to a holder of the described character.
Since the volume of the upper portion of the
cavity 3 is relatively large seedlings growing from a seed
planted centrally of the cavity adjacent its upper end
tend to grow to form seedlings of increased stem diameter,
377
for a given seedling height. The circular cross section
of the lower portion of the plug thus moulded by the
cavity facilitates the planting of the growing medium
plugs using conventional seedling-planting equipment. The
more steeply inwardly inclined portion 11 assists in
retaining the normally particulate growing material within
the cavity during the germination and seedling growing
process. The aperture 12 at the bottom provides for the
required drainage of the cavity, and when exposed to free
air, prevents growth of the roots beyond the bottom of the
cavity and encourages active growth of roots from points
within the growth medium.
Since the cavity and hence also the plug of
growing medium when disposed therein, has rounded corners,
prob]ems of moisture loss from sharp corner portions of
the transplanted growing medium are reduced or avoided and
the plug will be easy to remove from the cavity in
question.
The somewhat prismatic shape of the upper
portion of the cavity leads to formation of a growth
medium plug which holds together well and is well
penetrated by roots since the corners of the hexagonal
portions are not excessively remote diagonally from the
seed which is the centre of root growth.
Desirably, in order to reduce the quantity of
plastic required for the moulding, each cavity is defined
by a side wall which is in the form of a thin tubular
shell.
Preferably, the container is moulded, e.g. by
injection moulding from a thermoplastic material,
preferably polyethylene which is filled with a black
ultraviolet resistant pigment.
A further advantage of the present
arrangement is that the closely packed hexagonal array
reduces the amount of infrared-absorbing plastic exposed
1~5~3~377
at the upper surface of the container. This reduces the
quantity of solar energy absorbed by the container and
reduces the amount of heat energy transferred to the roots
of the seedling, thus reducing solar heat-induced root
damage.
The container is well adapted for use in
mechanized procedures wherein quantities of growth medium
are dispensed automatically into each cavity, and a seed
may likewise be introduced automatically into the growth
medium. The container may then be maintained under
carefully regulated temperature and humidity conditions,
in order to promote germination and growth of the
seedling. After a period of growth the container with the
seedlings in it can be taken to the site where planting is
to be conducted.
The container is especially well adapted for
use in the germination and growth of tree seedlings for
use in the planting of forests, for example for forest
regeneration purposes.
