NL8500721A - Plastic trough to propagate rooted plant cuttings in nutrient soln - has bottom sides and end walls and guides for plant retaining element, bottom having lowered centre to ensure adequate film - Google Patents

Abstract

The plastic, e.g. (extruded) PVC, trough (1) for growing rooted plant cuttings using a nutrient soln. comprises a bottom (2), side walls (3,4) and end walls and is provided with at least one inlet and an outlet for the solution and channels (10a,c, 12a; 10b,d, 12) or the like to receive (insert) plant retaining means, e.g. a strip with openings. The trough is provided with means to ensure availability of a film of nutrient soln. of adequate thickness on the trough bottom, which pref. consist of a lowered central bottom portion (2a) extending over the full length of the trough. The bottom may be wholly or partly double-walled (2,13) and the intermediate space may contain heating tubes (19).

Description

'' iïfHfi - * i 855006 / vdV / kd

Short indication: Plastic growing trough with lowered bottom part.

The invention relates to a plastic growing trough for growing plants on an aqueous culture medium, comprising a bottom of the greenhouse bounded on both sides by upright walls, as well as a closed front and rear side, at least one inlet and a discharge for aqueous culture medium and gutter members which can cooperate with plant retention parts.

Such a plastic cultivation trough for growing plants in which a thin film of an aqueous culture medium 10 flows over the bottom of the closed plastic growth trough, so that no light, dirt or fallen plant parts can enter the nutrient medium, has been described in an older unpublished patent application.

When using this plastic growing trough, it has been found that 1-15 may not always achieve optimum results depending on the crop and the season.

A common drawback is unsatisfactory root formation when placing cuttings with root roots in such a well as it is very difficult to always properly contact these root roots with the thin film of the culture medium flowing over the trough bottom or to keep. In addition, it is very difficult to maintain a film of sufficient thickness on the bottom on the planar bottom.

The object of the invention is now to provide a plastic growth trough of the above-mentioned type, wherein these drawbacks do not occur.

This object is achieved according to the invention in that the growth trough is designed with liquid film flow control means 30.

When such liquid film flow control means are used, the root roots of cuttings can always be placed in a film of sufficient thickness on the bottom of the gutter, whereby optimum root formation and growth of the plants is guaranteed.

Flow control means are particularly easily and conveniently provided during the manufacture of such troughs if the trough bottom comprises a lowered bottom portion extending along the entire length of the trough.

The lowered bottom part of the gutter bottom extending over the entire length of the ground expediently adjoins on both sides in the direction of the upright walls extending upwardly inclined bottom parts.

Another factor that can adversely affect the growth of plants during cultivation in such a plastic growing trough is. the effect of the floor or ambient temperature on the liquid film that flows over the gutter bottom of the plastic growth gutter. Namely, when the plastic growing trough 15 is placed on the soil with the trough bottom, the temperature of the soil under the growing trough will strongly influence the temperature of the culture medium flowing through the plastic growing trough.

According to an advantageous embodiment, the growth trough therefore comprises temperature influencing means for eliminating or reducing the influence of ambient temperature on culture medium flowing over the trough bottom.

By using temperature influencing agents, the temperature of the liquid film flowing over the trough bottom of the plastic growth trough can be kept at a desired temperature without being adversely affected by the floor, ground or ambient temperatures.

The gutter bottom is particularly advantageous in at least partly double-walled form.

When the synthetic growth trough is constructed with a double bottom, it can in particular occur that the ambient temperature strongly influences the temperature of the culture medium flowing over the trough bottom.

A double bottom also offers the advantage that a greater stiffness can be given to the plastic growing gutter, so that thinner walls of the plastic growing gutter can suffice and, moreover, the handling is considerably greater. 850 0 7 2 1 - -3-

Finally, heating means can be provided with particular advantage in the double bottom to maintain an accurately determined temperature in the double-walled gutter bottom.

Finally, the double-walled bottom gives the advantage that the gutter can easily be fixed on supporting structures without projecting parts on the gutter which would complicate the storage and transport of the gutters.

Although a double-walled gutter bottom is recommended as a preferred embodiment above, it will be clear that the temperature influencing means may also consist of, for instance, a foamed plastic layer located under the bottom.

In order to reinforce the gutter bottom, which is constructed in double-walled form or with plastic foam, it may be recommended to provide the gutter bottom with longitudinal reinforcing ribs.

The upright walls of the plastic growing trough are also expediently designed to be double-walled in order to be able to maintain an optimum temperature in the plastic growing trough during cultivation of plants.

Finally, the invention also relates to a method for growing plants using a plastic growing trough according to the invention.

The invention will now be elucidated on the basis of an exemplary embodiment with the aid of the drawing, in which:

Fig. 1 - shows a plastic growth trough according to the invention in perspective;

Fig. 2 - a section of a plastic gutter according to fig.

30 1; and

Fig. 3 - a plastic gutter according to the invention in yet another embodiment.

The figures show a plastic growing trough 1 consisting of, for example, polyvinyl chloride, comprising a bottom 2 and side walls 3, 4 as well as a front wall 5 and a rear wall 6 closing off the plastic growing trough.

8500721 -4-

The trough 1 is further provided with a plurality of feeds 7 and a discharge 8, while aqueous nutrient medium from storage container 11 is passed through pump 9 and feeds 7 into the growth gutter 1 and flows back via the discharge 8 into the storage container closed by a lid 5. 11 to prevent light from entering the nutrient medium in the container 11.

The nutrient medium is kept at a certain and / or adapted composition by adding nutrients and water to storage container 11.

The upright side walls 3, 4 of the plastic gutter merge via upright side wall parts 3a, 4a into upright end wall parts 12a, 12. These upright end wall parts 12a, 12 bear guide strips 10b, 10d and 10a, 10c respectively on their underside. The parts 12a, 10b, 10d and 12, 10a, 10c in this way form guides for a U-shaped element 17 provided with recesses 18 in which cuttings can be received.

By suitable selection of the U-shaped element 18 which serves as a plant retaining agent, the cuttings which have been rooted in another place and which have a certain length, can be brought into contact with the bottom of the plastic gutter during the placing the U-shaped element 17 in said guides.

It is generally recommended to root the cuttings 25 in a rooting gutter that is the same depth as the plastic growing gutter.

In figure 2 it can be clearly seen that the bottom 2 is made double-walled by joining an additional support bottom 13 via longitudinal ribs 15 with the gutter bottom 2. This can easily be done during the extrusion of the plastic growth channels according to the invention.

The gutter bottom 2 forms, with the reinforcing ribs 15 and the support bottom 13, a hollow tube which prevents floor, ground or ambient temperatures from being able to exert an important input on culture medium flowing over the gutter bottom 2.

To maintain an accurately determined temperature in the tube formed by the double-walled gutter bottom. 8 5 0 Q 7 2 1 •• s -5- port, it may be advisable to include heating means 19 in the double-walled gutter bottom.

The double-walled gutter bottom 2, 13, 15 gives a high rigidity to the plastic growing gutter, so that a smaller wall thickness of the plastic growing gutters can suffice,

Fig. 3 shows that not only the gutter bottom is double-walled, but also the upright walls 3 and 4, which are connected by means of reinforcing ribs 15 'to walls 3', 10 41 extending parallel to the upright walls 3, 4. In this case, sloping connecting walls 16 are present between the support bottom 13 and the outer walls 3 ', 4' which, with the upright wall parts 3, 4, form the double-walled wall parts.

In order to obtain a liquid film of a desired thickness at a certain location of the bottom of the plastic growing trough, it is recommended to design the plastic growing trough 2 with a lowered bottom part 2a extending over the entire length of the bottom, which connects on both sides to upwardly inclined bottom parts 2 'connecting to the upright 3, 4. In this way, it is possible to concentrate the liquid film in the lowered bottom part / so that the cuttings can be placed in this nutrient medium film when placed with the roots.

8500721

Claims (8)

A plastic growing trough for growing plants on an aqueous culture medium comprising a trough bottom bounded on both sides by upright walls, as well as a closed front and rear side, at least one inlet and a discharge 5 for aqueous culture medium and trough members which can cooperate with plant retaining parts, with the characterized in that the growth trough is provided with liquid film flow control means (2a, 2a '). Plastic growing trough according to claim 1, characterized in that the trough bottom comprises a lowered bottom section (2a) extending over the entire length of the bottom. Plastic growing trough according to claim 2, characterized in that the lowered bottom part of the gutter bottom extending over the entire length of the bottom connects on both sides in an upwardly extending direction in the direction of the upright walls (3, 4). bottom parts (2, 2 '). Plastic growing trough according to one or more of the preceding claims, characterized in that the trough members which can cooperate with plant retaining parts are designed as a guide for these plant retaining parts. Plastic growing trough according to claim 5, characterized in that the distance between the bottom of the guide (10c, 10d) and the bottom (2) is substantially equal to the length of the part of the cutting that extends below the plane through the bottom of the guide (10c, 10d). Plastic growing trough according to claims 1-5, characterized in that the growing trough comprises temperature influencing means (13, 15, 17) for eliminating or reducing the influence of ambient temperature on culture medium flowing over the trough bottom (2). Plastic growing trough according to claim 6, characterized in that the trough bottom (2) is at least partly double-walled. «8500721 1'lil - 7- A method for growing plants using a plastic growing trough according to one or more of claims 1 to 7. 3500721