GB2410881A - Plant cultivation device and method - Google Patents

Abstract

The device (1) comprises a tube (2) having a rim/annular plate (3) at a first open end and which extends laterally from the top end of the tube (2). Anchorage means in the form of spikes are provided at the other end of the tube for anchoring the device (1) into the ground in use. A method of cultivating plants is also described where the device is filled with a growing medium into which a seed is planted, germinated and subsequently the device is planted into the ground. The device may also comprise a flange (5) which controls the depth the device is located in the ground. The device may also comprise means to repel pests including providing a lip, a mutiplicity of spikes, a metal band or an abrasive surface on the device. Pesticide coatings or grease may also be applied. The device may also comprise a cover (20).

Description

24 1088 1 PLANT CULTIVATION APPARATUS & METHOD The present invention

relates to plant cultivation and equipment therefor. In particular, though not exclusively, the invention concerns apparatus for cultivating salad, leaf and root vegetables and a method of using this apparatus to grow such

vegetables.

In plant cultivation, the interface between salad, leaf or root vegetables and the soil is a prime area of vulnerability of the plant to attack by a number of pests such as slugs, cabbage root fly and cut worms that inhabit the soil surface. Additionally, weeds growing close to the vegetables are difficult to remove without using pesticides. Salad, leaf and root vegetables are generally treated intensively with pesticides during cultivation in order to deal with pest and weed problems. Moreover, the plant's contact with the soil leads to soil contamination of the produce as it is harvested. Root vegetables are generally washed prior to marketing thus leading to the problem of how dispose of the waste dirty water.

"Pesticide Usage in Scotland (Vegetables for Human Consumption 1999)" published by the Scottish Agricultural Science Agency, reports that 34% of lettuce crops were treated with methiocarb molluscicide, 50% of crops were treated with carbamate insecticide for aphids, and 16% were treated with organophosphorus insecticide for aphids. Methiocarb is a broad- spectrum poison toxic to non-target species such as ground beetles and small mammals. There is a growing desire to try and remove the need for these pesticides, in particular in relation to lettuce crops.

Some alternatives to pesticides are already known, such as the use of fine plastic netting to protect swedes from cabbage root fly. In this method the whole vegetable patch or field must be covered with the netting, making weed control and slug control difficult to carry out. As cabbage root flies lay eggs in the soil at the base of brassica such as cabbages and swedes, other protection systems designed for use by amateur gardeners attempt to cover the soil at the plant base using collars or other covers at the stem base (see, for example, US 5,918,411).

However, these must be fitted around the plant stem once the plant is established.

A number of slug barrier products are available on the market based on the use of a rough material, such as diatomaceous earth or roofing felt, that damages the undersurface of the slug.

Products using a copper strip that gives the slug a small electric shock are also available. Such products are generally specific to slugs and do not deal with weeds or other soil borne pests.

It is also well known (see, for example, US Patent Number 5,263,278) to use stem protecting tubes to protect relatively large plant seedlings, such as tree saplings, from physical damage. In this case a stem protecting tube is placed around an already growing sapling. Placing collars or tubes around existing plants may be an awkward and time consuming operation.

Additionally, as tree saplings are generally relatively large by the time they are transplanted into their intended permanent positions in the ground, they are not particularly susceptible to damage from small pests such as slugs and snails.

A common disadvantage of all these prior art systems is that they tend to be "single approach" solutions in that each of them is designed to deal with a single particular type of pest or 1S problem, for example slugs/snails alone, or cabbage root fly alone, or to protect the growing plant from physical damage.

It is an aim of the present invention to avoid or minimise one or more of the foregoing disadvantages. In particular, one aim of the present invention is to provide a plant growing system which addresses multiple problems such as the problems of slug/snail damage, cabbage root fly, and aphids, and providing physical protection from weeding machinery. Another aim of the invention is to provide a plant growing system particularly suited to the growing of annuals such as, for example, lettuce, salad and root vegetables.

According to a first aspect of the present invention there is provided a plant cultivation device comprising a tube having a rim provided at a first open end thereof and extending laterally from the tube, and anchorage means provided at a second end of the tube for anchoring the device in the ground.

The inventive device has the advantage that the tube can be filled with soil or other growing medium and a seed or seedling can be planted in the open first end of the soil-filled tube or a bare root transplant or plug may be transplanted, at or near the top of the tube. By anchoring the tube in the ground such that the rim is disposed above the surface of the ground, the seedling and resulting plant therefore grows from a height IS raised above the level of the surrounding ground and is thus largely protected from soil based pests. Additionally, as the plant roots grow inside the tube, the plant is protected from weed control equipment, such as strimmers or mechanical weeders, used to remove weeds growing close to the device. Moreover, an additional benefit is that the seed can be planted and cultivated in the device and then transplanted in-situ in the device, to a field or other plant growing environment e.g. an allotment or garden. The plant can thus remain in the device for its entire life.

Preferably, the rim is in the form of an annular plate. Said annular plate may be planar or curved to a greater or lesser extent. The annular plate may be funnel shaped from its top portion towards the tube. Preferably, the device further includes depth control means, which may conveniently be in the form of a flange or skirt attached to or integrally formed with the tube and spaced from the annular plate, for controlling the height at which the annular plate is disposed above the ground, when the device is anchored in the ground.

An outer edge of the annular plate is preferably provided with a circumferential lip which extends in a direction generally parallel to the tube and towards the anchorage means. Most preferably, the device further includes pest barrier means for protecting the plant from pests. The pest barrier means may conveniently comprise a physical barrier in the form of a metal band such as copper across which slugs are generally unwilling to cross; an adhesive surface such as sandpaper) or a multiplicity of spikes attached to the underside of the annular plate and/or the lip thereof. The pest barrier system may alternatively, or additionally, include barrier materials such as pesticide coatings or grease applied to the underside of the annular plate and/or lip. It will be appreciated that the lip acts to deflect water from the annular plate and to protect the pest barrier system provided on the underside of the plate.

An inner surface of the tube may optionally be provided with a plurality of ridges running generally parallel to the axis of the tube, to direct root growth down the tube. The anchorage means may conveniently comprise one or more prongs or other spikes configured in the wall of the tube at the second end of the tube, for piercing the ground and supporting the device in the ground. Preferably gaps are provided in the tube wall between the prongs or spikes to allow plant roots to grow laterally out of the tube, the second end of the tube preferably being open ended. Alternatively anchorage means may be provided by a protruding helix extending externally down the exterior surface of the below-ground portion of the tube enabling the device to be screwed into the ground. This might be used in cases where a plant requires a high degree of anchorage.

Optionally, the device may further include a removable lid or cover for enclosing a space above the annular plate in which the plant may grow. The annular plate may be provided with attachment means for removably attaching the lid or cover to the plate.

According to a second aspect of the invention there is provided a method of cultivating plants, preferably salad, leaf or root vegetables, the method comprising the steps of: filling each one of a plurality of devices according to the first aspect of the invention with soil, compost or other growing medium; planting a seed in the open first end of each one of the plurality of filled devices; germinating the seeds in the devices so as to grow seedlings; planting the devices containing the growing seedlings into the ground at spaced apart intervals and allowing the seedlings to grow into plants; and harvesting the grown plants by lifting the devices out of the ground. Preferably the devices are planted in the ground such that the open first ends of the devices, in which ends the seeds have been planted, are disposed above the level of the surrounding ground, whereby the plant grows from a height above the ground level. The method may additionally include weeding between the planted devices using mechanical weeding equipment such as strimmers. The method may further include attaching a respective removable cover to each of the devices, under which cover the seedling/plant grows. The harvesting step is preferably carried out by a machine designed to lift the devices from the ground without the grown plant/vegetable coming into contact with the machine, in order to minimise damage to the plant/vegetable.

It will be appreciated from the above that the invention offers a more "whole" approach to the various problems associated with growing annuals such as salad, leaf and root vegetables then the solutions offered by the prior art. In particular, the problem of slugs/snails is addressed by the rim provided at the upper open end of the tube and by any pest barrier devices positioned underneath this rim. The problem of cabbage root fly eggs laid in the soil is avoided by the fact that the plant grows from an elevated height above the ground level and the roots of the plant are protected by virtue of being inside the tube. The problem of air borne aphids can be dealt with by utilising the (optional) lid or cover to enclose the growing space above the rim. Additionally, the growing plant is protected from physical damage from weeding equipment used to weed between the growing plants due to the fact that the plants themselves are raised above the ground level and the roots are protected by the tube which is held securely in the ground by the anchorage means.

Moreover, as the invention thus negates the need for herbicide (100% of Scottish lettuce crops were treated with herbicide) gives clear and important environmental benefits, it is a clear advance over existing systems and should, if adopted in field scale lettuce crops, contribute to the survival of farmland birds, many species of which are currently under serious threat.

Preferred embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings in which: Fig. 1 is a perspective side view of a plant cultivation device according to one embodiment of the invention, planted in the ground but with the ground shown in cross section to reveal the portion of the device disposed below the surface of the ground; Fig. 2 is a cross-sectional side view of a portion of the device of Fig. 1, taken along the axis X of the device of Fig 1; Fig. 3 is an end cross-sectional view of a tubular portion of the device of Fig. 1, taken along the line BB' in Fig 1.; Fig. 4 is a side view of a lower portion of the device of Fig. 1; Fig. 5 is a perspective side view of the device of Fig. 1 with a plant growing therein, and with a cover disposed on the device; Fig. 6(a), (b) and (c) illustrate three different stages respectively in an amateur production system; Fig.7 is a side view of a lower portion of a modified version of the device of Fig. 4; and Fig. 8 is a side view of another embodiment of the device.

An example embodiment of a plant cultivation device according to the invention is shown in Figs. 1 to 5. The device 1 comprises a growing tube 2 having a flat rim in the form of an upper annular plate 3 attached to one end thereof, the plate 3 lying in a plane generally perpendicular to the axis X of the tube 2.

The other end of the tube is designed to be anchored in the ground G by means of prongs or spikes 4 formed by cutting away sections of the wall of the tube 2 which is open ended. A lower annular plate or flange 5 is attached to (or integrally formed with) an outer surface of the tube 2 and acts as a depth control device. As shown in Fig. 1, in use the device 1 is inserted into the ground G using the prongs or spikes 4 at the end of the tube 2 to pierce into the ground to a sufficient depth to firmly anchor the device 1 in the ground and until the lower annular plate 5 makes contact with the ground. The upper annular plate 3 is thus disposed at a predetermined height H1 above the surface of the ground G. In this particular embodiment which is designed for growing a "little gem" lettuce, the lower plate 5 is spaced from the upper plate 3 by a distance HI of approximately 2cm to 3cm and the axial distance H2 from the lower plate 5 to the free ends of the prongs 4 is approximately 7cm to 18cm. The upper and lower plates 3, 5 have an outer diameter of approximately 4cm to loom. The upper plate 3 is provided with a central planting hole 6 via which a plant may be grown in the tube 2. The planting hole or aperture 6 may be of the same diameter and shape as the end of the tube 2 to which the upper plate 3 is attached, or may have a different shape and/or size designed to facilitate the growing of a specific plant/vegetable. The upper plate 3 is provided with a downwardly protruding lip 7 which extends circumferentially around the plate 3 and encloses a pest barrier system provided in the device 1. The barrier system comprises a primary barrier which is in the form of a multiplicity of short sharp spikes 9 of appropriate dimensions and spacing to deter pests that attach to the type of plants or vegetable to be grown in the device 1.

The barrier system includes a secondary barrier in the form of a coating 12 of pesticide or grease applied to the underside 10 of the upper plate 3 and/or the inner surface 11 of the lip 7.

Alternatively the coating could be of a plant extract or a rough surface coating to protect against specific types of pests. The downwardly directed lip 7 deflects water and protects the pest barrier system.

The tube 2 provides stem and upper root protection for the plant which will grow in the device 1. The tube is generally cylindrical but is slightly tapered in the axial direction (so as to narrow in diameter towards the prongs) to allow stacking with other such devices 1. The tube 2 is also ridged on its inside surface 14, the ridges running generally axially down the tube 2, as shown in Fig. 3 which shows an embodiment having five such ridges 15. These ridges direct root growth. The lower plate 5 as well as providing depth control also performs a stabilization function by making contact with the ground G when the device is inserted in the ground. The tube 2 is made of a material having sufficient strength to protect a plant growing therein from damage from mechanical weed control machines, such as from strimmer systems, which may be used to remove weeds growing near to the device 1. The tube 2 is also designed to be of sufficient length so that the depth of the tube in the soil protects the growing plant against soil surface pests such as cabbage root fly. The prongs or spikes 4 providing the anchorage system must also be of sufficient strength and length to anchor the type of plant/vegetable to be grown in the device 1. In the Fig. 1 embodiment, intended for growing "little gem" lettuce, the length of the prongs is in the range of 4 to 12cm.

An optional closed aerial cover 20, indicated in broken outline in Fig. 1, may be attached to the upper plate 3 to protect the growing plant against aerial pests and to enhance the growing environment in order to accelerate growth.

To use the device 1, the interior 16 of the tube 2 is filled with soil or compost (or other growing medium) and a seed is planted in the aperture 6, at the top of the tube 2. The seedling is germinated in-situ in the device 1. Alternatively a bare root transplant or plug (not shown) may be transplanted into the device. The tube may be placed on a tray or other device to stop the soil falling out of the open end of the tube when it is first filled with soil, but once the seedling is established the root system of the seedling will retain the soil in the tube when the tube is removed from the tray for planting out. Alternatively, in a commercial system involving many thousands of devices 1, a sleeve made of biodegradable plastic or fibre material may be used to cover the open end of each tube 2 to retain the solid therein when the tubes are first filled with soil (or other growing medium), thus allowing the tubes to be individually handled in an automated system, such as a conveyor system. Using a closed cover 20 advances the growth of the seedling by providing a warm environment and protects is against aerial pests. The cover 20 may, for example, be made of fine plastic netting (for example the product sold under the Trade Mark ENVIROMESH), fleece material, or a perforated plastics material. Fig. 5 illustrates a little gem lettuce 25 growing in the device 1, under the cover 20.

The ridges 15 provided on a inner surface 14 of the tube 2 also give strength to the tube 2 and prevent root spiralling. The precise shape and dimensions of the anchorage system provided by the prongs or spikes 4 may vary depending on the specific vegetable/plant being grown in the device 1, but essentially the spikes 4 must be strong enough to be pushed into the soil to a sufficient depth to anchor the vegetable/plant until its root system is established. Gaps 30 are provided in the side of the tube 2, between the spikes 4, to allow roots to grow laterally and downwards from the device 1. The axial length of the portion of the tube 2 extending from the upper end of the spikes to the lower plate 5 is designed to be sufficiently long (in the Fig. 1 embodiment, in the range of 3 to 12cm) to substantially prevent pests from getting to the growing plant by entering the device 1 via the gaps 30 between the spikes 4.

In the illustrated embodiment the diameter of the aperture 6 in the upper plate 3, and also the diameter of the tube 2 at the upper end thereof, is approximately 2 to 4 centimetres and the tube 2 tapers down to a final diameter of between approximately 1.8cm and 3.8cm at the tip of the prongs 4.

It will be appreciated that a multitude of seedlings can be cultivated by providing a respective device 1 for each plant to be grown and arranging the devices 1 in the ground at suitably spaced apart intervals, for example in conventional style rows, so that strimming or other mechanical weeding can be carried out between the rows. The device 1 protects the growing plants from the strimming machine. When ready to harvest, the entire device 1 with the mature plant still contained therein, is lifted from the ground, preferably without the plant being touched by the person or machine carrying out the lifting process. The grown plant, such as a lettuce, can be easily cut or removed from the device 1 which can then be washed and reused. Alternatively, the device 1 may be made of a plastics material which is designed to be disposable or biodegradable.

Figs. 6 (a) and (b) illustrate an amateur cultivation system using devices 1 as above described. In this system in a greenhouse (not shown) a polystyrene or similar block or specially designed plastic structure 40 is provided with bores or holes 45 (extending through the structure 40) for supporting the devices 1, one hole 45 being provided for each device 1.

The block 40 is placed on a suitable tray (not shown) to retain soil or compost. The devices 1 are placed in the holes 45 and are each filled with seeding compost. Seeds are then sown as required in each device 1. The seeds germinate and grow into seedlings 50. The roots of the seedlings 50 grow down the tube 2 of the device 1, through the compost in the tube. The device 1 is ready to transplant (from the structure 40) into the ground once the roots are well established down the entire length of the device 1. The plastic structure 40 is frangible and designed to come apart along lines marked A in Figs. 6a and b in order to allow easy removal of devices containing the seedlings and root systems, for planting. The devices 1 are then planted directly into the soil in the ground where the plants are to be grown e.g. in the garden or allotment, such that the annular rim l0 3 is disposed at a desired height above the ground as afore- described. A plastic or fabric cover 20 is put over each device 1 to protect the developing seedlings from pests and from weathering and to accelerate growth, as afore-described. A strimmer or similar weeding device can be used to remove weeds growing between the devices 1. It is safe to strim right up to the device 1 as the tube 2 protects the growing plant. When the plant/vegetable grows to reach the top of the cover 20, the cover can either be removed entirely, or replaced with a larger cover. In some cases, such as for little gem lettuce, one cover can be used from seedling through to harvest. When the plant/vegetable is ready to eat the entire device 1 is then lifted from the ground with the plant/vegetable still held therein. Once the plant has been cut off or removed the device 1 can be cleaned and reused.

It will be appreciated that a professional, commercial growing system is also possible using the same principles as the afore- described amateur system. In this case specialist machinery may be provided for filling the devices 1 with compost/soil and sowing the seeds therein. The machinery may also be designed to identify "blanks" (i.e. devices 1 where the seedlings have not grown) prior to planting the devices 1 in the ground. Dedicated machinery may be provided to carry out the planting process as well as to add and remove the covers 20 as required, and to harvest the devices 1 when the plants/vegetables are ready to be harvested. The seeding and planting machinery may be based on existing technology already available for producing plant plugs.

Weed control may be carried out by an inter-row surface cultivator and side strimmers designed to remove all weeds adjacent to the devices 1. In one possible embodiment the individual covers or lids 20 are added and removed using a suction system. For harvesting, a harvester incorporating a lifting and conveyor system may be designed to lift the devices 1 from the ground without the vegetable/plant coming in to contact with the machinery: the only contact would be between the device 1 and the machinery. This would minimise damage to

the plant/vegetable.

It will be appreciated that the described invention is unique because rather than targeting a single problem such as slugs, it provides as holistic system addressing seeding, transplanting, weed control, pest control and harvesting issues. The inventive device 1 raises and separates the salad, leaf or root vegetable from the ground surface, preventing attack by soil surface pests and importantly allowing mechanical weed control. Moreover it will minimise soil contamination of root vegetables thus reducing the amount of dirty water produced in the preparation of root vegetables for marketing. Additionally the pest barrier system on the underside of the upper plate 3 is designed to eliminate the need for molluscicides and for insecticides lO generally used for specific soil borne pests. Moreover the device has a stem and upper root protection system designed to repel soil pests and facilitate complete control of weeds without the use of pesticides. It will be readily appreciated that the exact dimensions of the device 1 will depend on the type of plant/vegetable which is intended to be grown in the device 1. In general, the diameter, shape and depth of the tube 2 must be sufficiently large to allow the desired plant to grow to its full size and to contain enough soil for the plant to obtain sufficient nutrients to enable it to grow to its full size. In general for salad, leaf and root vegetables or other annual plants, the device is designed so that the upper plate 3 is raised, for pest barrier and weed control purposes, approximately 2-4 cm clear of the ground surface. However, in exceptional uses such as for the cultivation of strawberries, the upper plate 3 might be raised by as much as 30 cm above the ground in order to keep the fruit clear of the soil (this would also help deter larger pests such as rabbits). In this case the length of the prongs at the base of the tube 2 will be proportionately greater as will the aperture 6.

For the avoidance of doubt the term "plant" as used herein is intended to include all types of plants, including vegetable, ornamental and fruit plants, although it will be appreciated that the invention is particularly suited for the growing of salad, leaf or root vegetables.

It will be appreciated that various modifications to the above described embodiments are possible within the scope of the invention. For example, although in the embodiment of Figs.1,4 and 5 the prongs or spikes 4 are formed as downwardly tapering IS spikes by cutting V-shapes in the tube 2, whereby the width of the spikes gradually decreasing away from the lower plate 5, other shapes of prongs/spikes are also possible. Fig.7 illustrates alternative spikes in the form of two spaced apart prongs 54 having generally uniform thickness along their length.

Fig. 8 shows a further alternative arrangement wherein the spike is in the form of a single prong 54 having generally uniform thickness along its length. In another possible embodiment, instead of spikes or prongs for anchorage, the exterior surface of at least a portion of the tube 2, most conveniently the below-ground portion of the tube 2 (namely the portion of the tube extending down below the lower plate 5) is provided with a protruding helix extending externally down the tube, thereby enabling the device to be screwed into the ground. This embodiment may be particularly suited to applications in which the plant requires a high degree of anchorage.

Claims (15)

1. l. A plant cultivation device (l) comprising a tube (2) having a rim (3) provided at a first open end thereof and extending laterally from the tube, and anchorage means (4) provided at a second end of the tube for anchoring the device (l) in the ground.
2. 2. A plant cultivation device as claimed in claim l wherein, the rim is in the form of an annular plate.
3. 3. A plant cultivation device as claimed in claim l or claim 2 which includes depth control means.
4. 4. A plant cultivation device as claimed in claim 3 wherein said depth control means is in the form of a flange formed with the tube and spaced from the annular plate, for controlling the height at which the annular plate is disposed above the ground, when the device is anchored in the ground.
5. 5. A plant cultivation device as claimed in any one of claims 2 to 4 wherein an outer edge of the annular plate is provided with a circumferential lip which extends in a direction generally parallel to the tube and towards the anchorage means.
6. 6. A plant cultivation device as claimed in any one of claims 2 to 5 provided with pest barrier means selected from the group including a metal band around said tube; an abrasive surface around said tube; and a multiplicity of spikes attached to the underside of the annular plate and/or the lip thereof.
7. 7. A plant cultivation device as claimed in any one of claims 2 to 5 wherein said pest barrier system includes barrier materials selected from pesticide coatings or grease applied to the underside of the annular plate and/or the lip thereof.
8. 8. A plant cultivation device as claimed in any one of claims 1 to 7 wherein the inner surface of the tube is provided with a plurality of inwardly projecting ridges running generally parallel to the axis of the tube, to direct root growth down the tube.
9. 9. A plant cultivation device as claimed in any one of claims 1 to 8 wherein the anchorage means comprises one or more prongs or other spikes configured in the wall of the tube at the second end of the tube, for piercing the ground and supporting the device in the ground.
10. 10. A plant cultivation device as claimed in claim 9 wherein gaps are provided in the tube wall between the prongs or spikes to allow plant roots to grow laterally out of the tube.
11. 11. A plant cultivation device as claimed in any one of claims 1 to 10 wherein the second end of the tube is open ended.
12. 12. A plant cultivation device as claimed in any one of claims 1 to 11 wherein said anchorage means is provided by a protruding helix extending externally down the exterior surface of a below- ground portion of the tube enabling the device to be screwed into the ground.
13. 13. A plant cultivation device as claimed in any one of claims 2 to 12 provided with a cover for enclosing a space above the annular plate in which a plant may grow.
14. 14. A method of cultivating plants, including salad, leaf or root vegetables, which method comprising the steps of: filling each one of a plurality of devices according to any one of claims 1 to 13 with soil, compost or other growing medium; planting a seed in the open first end of each one of the plurality of filled devices; germinating the seeds in the devices so as to grow seedlings; planting the devices containing the growing seedlings into the ground at spaced apart intervals and allowing the seedlings to grow into plants; and harvesting the grown plants by lifting the devices out of the ground.
15. 15. A plant cultivation device substantially as described hereinbefore and with reference to Figs. 1 to 5 or Fig. 7 or Fig. 8 of the accompanying drawings.