IE46725B1 - Plant propagating body - Google Patents

Abstract

The plant propagating body comprises a plurality of connected parallel tubular foamed polystyrene containers 3. The containers 3 are connected together by a web 2 which is integrally moulded with the containers 3. The containers 3 each have a top opening 3a and a bottom opening 3b. The interior of each container 3 is occupied by a non-toxic porous or fibrous plug 5 which has a plurality of interstices some of which are of capillary dimensions. The plant propagating body has particular application in the propagating of a seed - placed on top of the plug 5 for example - to a seedling which may then be transplanted in a hydroponic module or transplanted to a more conventional horticultural medium such as soil.

Description

This invention relates to plant propagating trays. More specifically it relates to trays for the reception of seeds for germination, and for the propagation of the resultant seedlings.

According to the invention there is provided a plant propagating tray comprising a connected array of parallel tubular pots of closed-pore foamed plastics material each being open at both ends, each having one of its ends in a plane, and all being disposed on the same side of said plane, the connections between the pots being sufficiently weak to allow the array to be readily broken into separate pots without damage to the latter, and the interior of each pot being occupied by a plug which extends to meet said plane and has some interstices at least some of which have capillary dimensions.

The connections between the pots preferably comprise a web of the closed-pore foamed plastics material, moulded integrally with the pots, and disposed parallel to said plane. The web connects for preference the ends of the pots which are remote from said plane.

The closed-pore foamed plastics material is preferably of a density adapting it to float high in water. a U 4 ~ ·> - 3 Foamed polystyrene, as commonly made from beads of solid polystyrene, is the material of choice.

The tubular pots are preferably of right cylindrical form. The interior walls of the pots may taper towards the said plane (which plane defines the bottom of the plant propagating tray in use) th : better to support the plugs against falling from the pots under their own weight when wet.

The plugs may be porous or fibrous. The interstices of capillary dimensions are intended to soak water or nutrient solution upwardly through the plug in use, to assist in the propagation of a seed which is placed on or in the top region of the plug. The plant propagating tray meanwhile rests or preferably floats (in use) in a shallow layer of water or nutrient solution in a trough. The water or nutrient solution may be continuously removed from the trough and recirculated thereinto.

The interstices of greater than capillary dimensions are intended to permit root development downwardly through the plug in use.

The plug material may be, for example, cotton wool or other cellulose wadding, glass fibre, rock wool, wood shavings, peat moss, or open-pore foamed plastics material such as phenol formaldehyde, urea formaldehyde or polyurethane resins. It must, needless to say, be non-toxic to seeds and seedlings, and remain physically and chemically unaffected by prolonged contact with-water or plant nutrient solutions, as of course must the material of the remainder of the plant propagating tray. The plug extends to meet the aforementioned plane, which plane defines the base of the plant propagating tray in use. Thus the plug s contacts the water or nutrient solution in which the tray stands or floats in use. Capillary attraction thereafter ensures an adequate but not excessive supply of water to the body of the plug, including the top 6 7 2 Si region thereof where, in use, a seed is placed. An excessive supply of water would he one so copious as to restrict th.e supply of air to the seed, since both air and moisture are necessary for germination.

The connections between the tubular pots, as said above, are sufficiently weak to allow the array to be readily broken manually into separate pots. This is to facilitate transplanting of the seedlings when they have reached the appropriate stage of development, by which stage their root tips will normally project from the lower open ends of the pots. This feature can be realised in practice by providing that the tubular walls of the pots are substantially thicker than the web or other connecting element that binds the pots into a unitary tray, so that under manually applied stress the web yields while the pots remain intact.

Transplanting may be effected into beds of soil, peat moss or other conventional cultivation medium. Alternatively it may be effected into an apparatus for hydroponic cultivation, if the apparatus is provided with means for supporting the tubular pots with their contained seedlings. A convenient means for supporting them is a hydroponic module having nutrient solution containers of covered form, the covers being perforated with openings adapted to accept and support the tubular pots. In a particularly convenient procedure, the hydroponic module has substantially horizontal tubular channels for nutrient medium, the upper aspect of which channels is perforated with holes into meh of which a tubular pot, broken off from a plant propagating tray according to the invention,' can be inserted like a cork into a bottle. - 5 Thue the roots of the seedlings are placed in contact with the hydroponic nutrient medium by dangling thereinto from the bottom openings of the tubular pots. When a plant has grown beyond the necessity for support by the encircling walls of the tubular pot, the vot, being soft, will yield before the expansion of the plant body. Alternatively the pot may be broken away manually and the fragments discarded.

The invention will be described in greater detail in the following example, illustrated in the accompanying drawings, in which:Fig. 1 is a perspective view of a plant propagating tray; Fig. 2 is a perspective view of a single tubular pot broken off from the tray of Fig. 1; Fig. 3 is an axial section of the pot of Fig. 2; and Fig. 4 is a perspective view of the pot of Fig. 2, with a seedling established therein. .

Referring now to the drawings, a plant propagating body or tray 1 is an integral moulding in white foamed polystyrene measuring 50 cm x 40 cfo x 5 cm. It is made by steam 2o foaming polystyrene beads in the mould, and comprises a sheet of thickness 3 mm having a rectangular array of 12 x 10, * i.e. 120, tubular containers or pots 3 depending therefrom, each being of external diameter 3 cm and length 5 cm including the thickness of the sheet 2. Each container 3 is open at both ends, the top opening 3a (which is also a hole through the sheet 2) being of diameter 1.5 cm. The bore of each container tapers to a bottom opening 3b 1 cm in diameter at the free end thereof. Thus the container walls increase in thickness downwardly from 7.5 mm to 10 mm. - 6 The*free end of each container is in the same plane such that the said plane includes the bottom surfaces or base 3c of all the containers 3 in an intact plant propagating body 1. •ί ii ‘7 2 5 -7The body 1 will float in water in the attitude shown in Fig. 1 of the accompanying drawings.

When‘broken off manually from the body 1, an individual container 3 presents an irregular flange of fracture, 3 mm thick, about its upper periphery, but this is quickly and easily broken off and rubbed by hand tp an insignificant if slightly rough surfaced collar 4, as shown in Figs. 2-4.

The interior walls 9 of each container 3 is tapered inward from the top opening 3a towards the bottom opening 3b. The interior of each container 3 is occupied, at least partially, by a plug 5 formed from an open-pore foamed phenol formaldehyde resin having on the one hand a plurality of interstices (now shown) of capillary dimensions and further some voids (not shown) of dimensions larger than capillary dimensions and sufficiently large to establish a rooting communication between the ends of the container 3, for example for the roots 6 of a seedling 7, as shown in Fig. 4 of the accompanying drawings. The bottom opening 3b is shown as a single opening it will be understood that the opening 3b may consist of a lattice work integral moulding of the container material.

In use, a seed 8 is placed on the upper region of the plug 5 in every container 3 of a plant propagating, body 1. The body 1 is then placed floating on a shallow layer of water of perhaps 1 cm depth in a suitable trough. The trough bottom may be fixed at a slight inclination to the horizontal whereby slow « drainage of the water takes place, the water being continuously replaced or recirculated by conventional means. The trough and contents are then placed in a suitable environment, as regards temperature, light and ventilation, for propagation of the seeds to seedlings. Plant nutrient substances may be added to -84 6 7 3 5 the water, or the water replaced with a nutrient solution, as and when the progress of the seedlings necessitates such action. The plug 5 forwards moisture to the seed 8 by capillary attraction from the water in the trough.

Eventually roots 6 of the seedlings 7 appear trailing underneath the body 1. The seedlings are later judged suitable for transplanting, and the body 1 is broken up manually into 120 separate containers 3, each of which is inserted in a cooperating orifice in a hydroponic module in such manner that the container 3 is firmly held in a substantially upright attitude while the roots 6 are bathed by plant nutrient solution within the module. Hydroponic cultivation of the seedlings then proceeds in known manner.

Alternatively the containers 3 with seedlings 7 may be transplanted to a more conventional horticultural medium such as soil.

The plant propagating body 1 may alternatively, following suitable modification of the design thereof such as the elimination of sharp edges, be fabricated from a sheet of foamed polystyrene by vacuum forming.

The sheet 2 of foamed polystyrene is located for preference connecting the top ends of the containers 3. When the material thereof is light in colour i.e. white, this connection arrangement increases by reflection the amount of light reaching the photo- . synthetic parts of the seedlings. The sheet 2 may alternatively connect the middles or the bottoms of the containers 3. It may also be perforated between the containers 3 or otherwise diminished to any extent that still leaves the containers 3 joined to adjacent containers with enough rigidity to permit handling of the body 1 in use.

It is also envisaged that the plug 5 may be confined to the in use bottom end of the tubular -9ι 1 Container 3 and a seed supporting layer or bed of a germinating medium, for example peat moss, may be placed on top of the plug. The plug 5 through its capillary dimensioned interstices will supply moisture to the germinating medium which will allow the seed to root develop in the said medium in conventional manner. The voids i?. the plug 5 will continue to allow rooting communication as described above. In the case where the plug 5 and/or the germinating medium is of peat moss, the connecting web should preferably join together the bottom surface or base of each container. This construction is desirable to give a good floating property to the body in view of the peat moss weight relative to the light foamed plastics container material.

The advantages of the invention include its cheapness and ease of handling. It is also very well adapted for use in large-scale hydroponic cultivation and was in fact developed with that field of activity in mind.

It is also envisaged that while the present invention has been described as and is claimed as a plant propagating tray the said tray may to advantage also be used for the growing-on of seedlings.

Potentially fertile water areas such as inland waterways/lakes may serve as the trough in which the containers separately or as a connected body may be floated· It is also envisaged that the plant propagating tray may be used for growing-on in a glasshouse or like horticultural buildings. In this instance there is provided relatively large shallow (2-10 cms) pools/ponds within the glasshouse.

Claims (9)

1. A plant propagating tray comprising a connected array of parallel.tubular pots of closed-pore foamed plastics material each being open at both ends; each having one of 5 its ends in a plane, which plane in use defines the base of the plant propagating tray, and all being disposed on the same side of said plane, the connections between the pots being sufficiently weak to allow the array to be readily broken into separate pots without damage to the latter, and 10 the interior of each pot being occupied by a plug which extends to meet the said plane and which has interstices at least some of which have capillary dimensions

2. A plant propagating tray as claimed in claim 1 in which the connections between the parallel tubular pots 15 comprise a web of the closed-pore foamed plastics material moulded integrally with the pots and disposed parallel to the plane.

3. A plant propagating tray as claimed in claim 2 in which the web connects the ends of the pots remote from the 2q said plane.

4. A plant propagating tray as claimed in claim 1 in which the closed-pore foamed plastics material has a density adapting it to float in water.

5. A plant propagating tray as claimed in claim 1 in 25 which the closed-pore foamed plastics material is a foamed polystyrene.

6. A plant propagating tray as claimed in claim 1 in which the exterior walls of the tubular pots are of right cylindrical form and the interior walls of the pots taper - 11 upwardly towards the said plane.

7. A plant propagating tray as claimed in claim 1 in which the plug is formed from a porous or fibrous material whereby In use in a trough containing water or 5 a nutrient solution the interstices of capillary dimension soak water/nutrient solution upward through the plug in use to assist propagating a seed placed in the top region of the plug, and the said interstices and any interstices of dimensions larger than capillary 10 dimensions permit root development from said seed downwardly through the plug.

8. A plant propagating tray as claimed in claim 7 in which the plug is confined to the in use bottom end!of the pot and a seed supporting layer or bed of a 15 germinating medium is placed on top of said plug.

9. A plant propagating tray s-ubstantially as herein described with reference to Fig. 1 and Figs. 2, 3 and 4 of the accompanying drawings.