Chemical applicator for plant material

There is proposed an apparatus for introducing a chemical into a plant tissue of a target plant, including a body being graspable by a user, and an applicator portion attachable to or forming a part of the body, the applicator portion including a reservoir chamber for holding the chemical, and one or more elongate porous piercing elements, in fluid communication with the reservoir chamber, being configured to pierce the plant tissue, wherein the chemical within the reservoir chamber is drawn or moves into the one or more elongate porous piercing elements, such that as the one or more elongate porous piercing elements penetrate into or through the plant tissue the chemical is applied to an edge of a resultant incision therein.

FIELD OF THE INVENTION

The present invention relates to an apparatus for the impregnation or introduction of a chemical into the tissue of a target plant. In particular, the invention relates to the introduction of herbicide into a leaf or stem of a terrestrial or aquatic plant.

BACKGROUND OF THE INVENTION

Numerous devices have been developed or proposed for applying chemicals, such as herbicides, pesticides, fungicides and fertilisers, onto plants. These range from broad acreage spraying to direct application of a chemical to a target plant. However, spraying methods may be unsuitable where the target plants are aquatic plants or are terrestrial plants that are interspersed with non-target plants. Furthermore, spraying may not be suitable due to wind conditions or where rain may dilute the chemical, such that the concentration on the target plant is ineffective.

As a result, various devices have been proposed in the prior art that comprise direct application of the chemical onto the plant. One example is disclosed in U.S. Pat. No. 4,357,779, to MADDOCK, that describes a chemical applicator comprising a sponge connected to a chemical reservoir, wherein a flow of chemical from the reservoir to the sponge is controlled by a flow control valve.

One of the limitations with the sponge or absorbent pad type applicator is that the pad has a tendency to dry out due to its large surface area that is exposed to the environment. Furthermore, the chemical is still applied onto the surface of the plant, which may only absorb a fraction of the chemical applied, with the remainder being capable of being washed-off, thereby increasing the potential chemical exposure risk for non-target plants and animals.

U.S. Pat. No. 5,724,765, to WEGNER, discloses a herbicide applicator comprising a pair of opposable jaws, each including a herbicide reservoir connected to an absorbent pad by a conduit, and a plurality of needles. When a leaf or stem of a plant is grasped by the jaws, the needles penetrate the surface of a plant and the herbicide flows from the pad into the holes produced in the plant tissue by the needles. The device described in WEGNER however still applies a significant amount of herbicide to the surface of the plant, via the absorbent pads, which poses environmental issues.

The present Inventor has previously proposed an applicator that includes a reservoir and valves that are opened by the action of corresponding piercing members, which was the subject of International Application PCT/AU06/01887. However, it has been found that leakage can still occur through the valves and the piercing member must accurately align a corresponding valve which can be problematic.

It should be appreciated that any discussion of the prior art throughout the specification is included solely for the purpose of providing a context for the present invention and should in no way be considered as an admission that such prior art was widely known or formed part of the common general knowledge in the field as it existed before the priority date of the application. The term ‘impregnation’ used throughout the specification refers to the application of the chemical into the target plant tissue, in contrast to the application of the chemical to an exterior or outer surface of the target plant tissue.

SUMMARY OF THE INVENTION

In one aspect of the invention, but not necessarily the broadest or only aspect, there is proposed an apparatus to introduce a chemical into a plant tissue of a target plant, including:a body being graspable by a user; andan applicator portion attachable to or forming a part of said body, the applicator portion including a reservoir chamber for holding said chemical, and one or more elongate porous piercing elements, in fluid communication or capable of fluid communication, with said reservoir chamber, the porous piercing elements each having a length of greater than 1 mm and being configured to pierce said plant tissue, each of the porous piercing elements comprising a respective shaft and a generally tapered tip, wherein the shaft has a diameter equal to or greater than 0.5 mm, whereby a ratio of diameter of shaft to length of porous piercing element is less than 1:10;wherein said chemical within the reservoir chamber is drawn or moves into said one or more elongate porous piercing elements, such that as the one or more elongate porous piercing elements penetrate into or through said plant tissue the chemical is applied to an edge of a resultant incision therein.

The present invention therefore provides a porous piercing element that is configured to incise or pierce the plant tissue of the target plant and to carry the chemical into an interior of said target plant. This is in contrast to the absorbent pads of the prior art that apply the chemical predominantly to the exterior of the target plant.

In one form the applicator portion may comprise a first jaw, that is configured to cooperate with a second jaw on the body, wherein said first and/or second jaws are moveable and the plant tissue of the target plant is positionable therebetween, wherein upon closure or partially closure of the first and second jaws, the one or more elongate porous piercing elements piece the plant tissue of the target plant.

The one or more porous piercing elements are in fluid communication with and may be positioned within and extending out from the reservoir chamber when the first and second jaws are in an open position. Alternatively, the one or more elongate piercing elements may be positioned within recesses when the first and second jaws are in an open position to inhibit inadvertent contact or interference with the piercing elements. Such inadvertent contact or interference may occur if a child tries to play with the apparatus. Said recesses may be formed by a compressible member that surrounds the piercing elements or may be formed by a generally rigid member, which is retractable or moveable to permit the piercing elements to extend outwardly therefrom.

In one form the one or more elongate piercing elements only extend into a gap between the first and second jaws at a point just before the first and second jaws are fully closed or are abutting the tissue of the target plant. This means that the jaws can be wide enough to allow for the positioning of the plant tissue, such as a leaf or stem therebetween, but the piercing elements only extend outwardly when the jaws are close enough to inhibit the fingers of a child or user being positioned therebetween.

In a preferred form the one or more elongate piercing elements are in fluid communication with the reservoir chamber by way of a passageway. The one or more elongate piercing elements are preferably surrounded by a circumferential skirt that inhibits inadvertent contact therewith.

Preferably the one or more porous piercing elements are constructed from an absorbent wicking material. Accordingly, the reservoir can be filled with said chemical, which is drawn or impelled from the reservoir chamber by capillary action through the piercing elements to an outer surface thereof, such that it can be applied to the tissue when the piercing elements pierce the tissue of the target plant.

The porous piercing elements may be constructed from a metal or non-metal generally rigid or semi-rigid material.

In one form the porous piercing elements may be constructed from a generally rigid sintered material which acts to wick the chemical from the reservoir chamber to thereby present the chemical on an outer surface of the piecing elements, such that when the porous piercing elements pierce the plant tissue some of said chemical is wiped off on the edges of the incision. This introduction of the chemical into an interior of the plant tissue by way of a new cut or incision, in affect bypasses the normal local or systemic response of the plant to damage, thereby improving chemical uptake by the plant.

The sintered material may be a sintered ceramic, metal, aluminium oxide or silicon carbide. One of the advantages of a generally rigid sintered wick material is that it is both are sharp and durable for repeated use. However, the reader will appreciate that other types of material could be used. For instance, the porous piercing elements may be constructed from a porous thermoplastic material, cellulosic fibres or compressed fibres, such as wood pulp and cotton pulp, synthetic fibres, such as polyesters and polyolefins, superabsorbent polymers, such as polyacrylic acid, or felt.

Preferably the porosity of the porous piercing elements may be configured to deliver the chemical to all the tapered tips and outside of the shaft uniformly via capillary action. The material is also preferably non-drip. The flow rate through the porous piercing elements can be configured for the particular chemical being used. For instance, for more viscous fluids the flow rate can be increased depending upon the material used or the size of the particles of the sintered material used to form the porous piercing elements.

In another form the porous piercing elements comprise a relatively soft wicking material that is reinforced by a relatively rigid support member. The soft wicking material and rigid support member may be laminated or the soft wicking material may envelope an internal hardened rod. In yet another form, each piercing element may include a hardened tip.

The one or more porous piercing elements may be connected to or formed on a base plate of the same material. The base plate is configured to hold the porous piercing elements in place within the applicator portion. The porous piercing elements and base plate may be unitary in construction.

In one form the porous piercing elements may be elongate members having a length of between 1 mm and 5 mm and preferably 3 mm. The porous piercing elements may comprise a shaft that extends outwardly from the base plate and a tapered tip for incising the plant tissue. In one form the shaft may be 1 mm in length and the tapered tip may also be 1 mm in length. The diameter of said shaft may be between 0.5 mm and 2 mm and is preferably 1.5 mm.

The length of the porous piercing elements may be uniform or there may be a plurality of longer spikes and a plurality of shorter spikes or spikes or various lengths. In this way, the porous piercing elements are able to pierce the leaf of the plant notwithstanding its thickness, width or length.

The porous piercing elements or the tapered tip thereof may be generally cone shaped having a single curved face, or alternatively the tapered tip may include at least one face and a cutting edge. The tapered tip may include a plurality of generally planar faces and intermediate cutting edges. In one form the tapered tip may be generally pyramid shaped with four generally planar faces and four intermediate cutting edges. The cutting edges assist in the incision of the plant tissue and the generally planar faces provide a large surface area for application of the chemical thereto. The shaft of the porous piercing element may be generally cylindrical having a circumferential outer face, or have a polygon shaped cross sectional profile, such as a square shape, or the shaft may be tapered.

The sharpened tip may only penetrate the plant tissue a short distance before the shaft, which has a larger diameter, comes into contact with the incision. The short length of the tapered tip also means that it will be unlikely to penetrate human skin.

The spacing of the plurality of porous piercing elements may be between 0.5 mm and 5 mm, and may preferably be 1.5 mm. In this way, the porous piercing elements are able to pierce plant tissue however are inhibited from piercing human issue if the applicator portion comes into contact with a user's hand or foot because of the proximity of the adjacent porous piercing elements. The spacing works in a similar fashion to a bed of nails wherein the human tissue in not pierced even though an individual nail would pierce it. On the other hand, plant tissue, such as a leaf, is easily incised by the porous piercing elements when the jaws are moved together or the applicator portion is pushed down onto a prostrate weed.

A resiliently deformable member may surround the porous piercing elements. In one form the resiliently deformable member is a compressible foam pad. In another form the resiliently deformable member is a circumferential flexible skirt that surrounds the porous piercing elements. At rest the porous piercing elements are contained within or surrounded by the resiliently deformable member such as the compressible foam or flexible skirt, and in use the porous piercing elements can be extended outwardly therefrom. The compressible foam may be preferably a closed cell foam, wherein the chemical is inhibited from being drawn out of the porous piercing elements thereinto. The flexible skirt may be constructed from a natural or synthetic rubber material.

An ejector member may be used to push the leaf off the porous piercing elements. In one form the compressible foam pad that covers or surrounds the porous piercing elements or the flexible skirt acts as the ejector member. The foam pad or skirt may be overmoulded to the apparatus or attached with adhesive.

In another form a metal dome spring or plastic spring element or sprung plate may be used to ensure the leaf is detached from the porous piercing elements before the apparatus is withdrawn from around the leaf.

In one form the second jaw that forms an opposing surface to the applicator portion includes a compressible member such as but not limited to a foam pad. In this way when the first and second jaws are brought together the plant tissue is held between opposing foam pads or a foam pad and flexible skirt. This assists to hold the plant material in place so that the porous piercing elements can effectively pierce the plant tissue. As the porous piercing elements come into contact with the compressible foam pad on the opposing surface, when the first and second jaws are moved together, reversibly collapsible depressions or slots are formed in the compressible foam pad that correspond to the porous piercing elements. The portions of the compressible foam pad not impacted by the porous piercing elements act to support the back of the leaf or plant tissue to assist with the penetration of the porous piercing elements. In another form the compressible member is a portion of multiple hook material used in hook and loop fasteners. Wherein the flexible hooks are able to compress or move to accommodate the tapered ends of the piercing elements while still supporting the back of the leaf.

In a preferred form the opposing surface includes a plurality of parallel channels that align the porous piercing elements, wherein the ridges between the channels act on the leaf to assist in the incision thereof.

Due to the configuration of the porous piercing elements, which have multiple pores and pathways, any potential clogging with debris or plant residue will not adversely affect the efficiency of the porous piercing elements. The compressible foam pad may also assist in wiping the surface of the porous piercing elements clean, although this is not seen by the Inventor as being essential due to the nature of the material forming the porous piercing elements.

When not in use the first and second jaws may be brought into a partially closed arrangement such that the compressible foam pads abut or the flexible skirt abuts the opposing surface. This abutment acts to seal or at least partially seal the porous piercing elements to inhibit evaporation or escape of the chemical from the apparatus.

A respective lip may surround the compressible foam pads, wherein when in the partially closed arrangement the respective lips abut to thereby create a further barrier to movement of the chemical.

A vent groove, port or one-way valve in the porous member or a tank that forms the reservoir chamber, may be used to permit air to move out during filling of the reservoir chamber and/or to enter the tank as the liquid wicks out therefrom, to inhibit the formation of a vacuum.

In one form the applicator portion or a part thereof is detachable from said body. The detachable part may comprise or be attached to the first or second jaws. The detachable part may comprise the tank, which form the reservoir chamber, piercing elements and a foam pad or skirt. A clip or locking means may be used to secure the detachable part to the first or second jaw during use. Alternatively, the detachable part may frictionally engage the first or second jaw.

The locking member may comprise a sleeve that slidably engages a part of the body and is configured to both hold the applicator portion is place, and may act to hold the jaws of the applicator portion closed when not in use, whereby the piercing elements are concealed to inhibit unauthorised tampering or drying out thereof.

In this way, the reservoir chamber, piercing elements and foam pad/s or skirt can be replaced when the tank is empty or the piercing elements are damaged, wherein the body of the apparatus can be reused multiple times. Alternatively, for a single use apparatus the porous piercing elements can be detachable to assist with recycling of the device.

The reservoir chamber may be formed in a clear plastic tank that is ultrasonically welded or otherwise attached to the body or applicator portion. The clear plastic tank enables a user to identify how much chemical remains within the reservoir chamber. The porous piercing elements may be insert moulded into the applicator portion or tank. Alternatively, the porous piercing elements could be clamped in place or held using an interference fit, adhesive, ridge, etc. In one form the tank may include internal ribs or ridges to hold the base plate and porous piercing elements in place once assembled.

In another form the applicator portion is positioned or attached at an end of an elongate handle, such that in use the one or more porous piercing elements are configured to extended downwardly from the applicator portion to pierce the plant tissue of a target plant that has a generally prostrate growth habit.

In one form the applicator portion comprises a tapered tank that frictionally engages a recess in the end of said elongate handle, the tapered tank being attached to a support member that accommodates the porous base plate and porous piercing elements, such that the porous piercing elements depend from the base plate, a resiliently deformable member is attached to an underside of the support member and surrounds the porous piercing elements, such that when downward pressure is applied to an underlying target plant the porous piercing elements extend out from within the resiliently deformable member to thereby pierce the plant tissue of the target plant. Alternatively, the applicator portion or cartridge may be connected to the handle by way of cooperating bayonet fittings, cooperating threads, magnetic coupling or any other attachment means.

The apparatus may also include a guide member that guides the target tissue into the correct position between the opposing jaws to assist in the efficient use of the device. This may be useful where the apparatus is being used by a person with limited mobility, or where the apparatus is connected to, or includes, an extendable handle to treat a plant tissue that is located at a height above the ground and which is out of arms reach.

The apparatus may further include finger or hand guard/s that prevents the target tissue coming into contact with the hand or fingers of the user. This may be important where the apparatus is being used to treat brambles, thistles or stinging nettles. The guard/s is/are forward of the finger grips on the outer surface of the opposing jaws and extends outwardly both sides of the apparatus. The guard/s may be integral with the jaws or may be attachable thereto.

A cap may be reversibly attached over a part of the applicator portion to prevent evaporation of the chemical off the porous piercing elements and to protect them when not in use. The cap may include a locking device to prevent unauthorised tampering, for instance a ‘child lock’ could be used to prevent children from coming into contact with the potentially hazardous chemical contained within the apparatus. Where the apparatus includes opposing jaws the cap can be clamped over the jaws when they are in the abutting arrangement to effectively hold the jaws together for storage. Alternatively, where the apparatus comprises an elongate handle and depending applicator portion the cap may simply clip over the end of the applicator portion.

The reader will appreciate that since the porous piercing elements contain the chemical, very little is applied to the outer surface of the target plant during delivery. In this way, the potential for wash-off of the chemical is reduced and the chemical is applied to interior of the target plant, where it is more likely to be absorbed and therefore have the greatest efficacy.

The one or more porous piercing elements extend out from or are in fluid communication with the reservoir chamber, such that the one or more porous piercing elements normally contain a portion of the chemical within its pores for application to said plant tissue.

The use of multiple small porous piercing elements makes targeting of the plant, such as a weed much easier, as there is no need for careful alignment of the apparatus for thin leaves.

Furthermore, the total perimeter of the piercings is increased since there are multiple small holes. The Inventor envisages that this should lead to a greater take-up of the chemical by the leaf or other plant tissue.

A thin layer of elastomer may overlay the tips of the porous piercing elements to seal the unit during filling and transport, prior to use. The thin layer of elastomer will be pierced during first use. Alternatively, an adhesive film or foil may overlay the tips of the porous piercing elements, which are either pierced on first use or may be peeled off by the user prior to use.

The piercing elements are preferably configured to incise the leaf without tearing or cutting away any portion of leaf, since this may affect the uptake of the chemical.

In another aspect of the invention there is proposed a device for applying a chemical to a plant including at least one piercing member that substantially comprises said chemical, wherein the at least one piercing member is dissolvable or otherwise liquefiable for application to said plant.

The at least one piercing member being in a crystallised form that is dissolvable or otherwise liquefiable by an activating liquid or substance or plant enzyme or as a result of other chemical reaction.

The activating liquid or substance may be applied to the at least one piercing member from the chemical reservoir. Accordingly, the chemical to be applied to the plant is not contained within the chemical reservoir, as previously discussed, rather the activating liquid or substance is held with the reservoir in a similar fashion, as previously discussed with respect to the chemical, wherefrom it can be applied to the porous piercing member/s to dissolve or otherwise liquefy at least a part of the porous piercing member/s, such that at least a portion of the chemical is in a form that can be applied to the plant material.

In one form the liquid is water that is applied to the at least one piercing member to causes an outer layer to be liquefied so that it can be applied to the plant tissue as the at least one piercing member pierces the plant tissue.

The activating liquid may be applied to the leaf or plant prior to piercing by the piercing element. For instance, this could be achieved using a damp sponge pad of the applicator or a spray device or simply applying water to a plant using a garden hose.

The crystallised at least one piercing member may be a glyphosate (N-(phosphonomethyl)glycine).

The dissolvable at least one piercing member may include a carrier or bonding agent that in one form solidifies the chemical and allows for it to be liquefied under a desired condition.

In another form an active or inactive matric may be used to hold the chemical therein.

The at least one piercing member may be at least partly porous or may be generally solid but which allows an activating liquid or substance to penetrate thereinto.

In still another aspect of the invention there is proposed a method of applying a chemical to plant tissue of a target plant or plants, using a device with one or more porous piercing elements having respective lengths greater than 1 mm and being in fluid communication with a reservoir chamber, each of the porous piercing elements comprising a respective shaft and a generally tapered tip, wherein each shaft has a diameter of equal to or greater than 0.5 mm and a ratio of diameter of shaft to length of porous piercing element is less than 1:10, including the steps of:a) filing said reservoir chamber with a chemical, wherein the chemical is drawn or moves into the one or more porous piercing elements;b) passing the one or more porous piercing elements into or through said plant tissue of a first target plant whereby the chemical is applied to an interior of the plant tissue or side of an incision therein;c) withdrawing the one or more porous piercing elements from the plant tissue; andd) repeating steps b) and c) to treat said first target plant or a subsequent target plant or plants.

The plant tissue is pierced to assist with the uptake of the chemical by the target plant or plants. For instance, the cuticle of a leaf may be waxy, or the stem of a weed may be woody, which would all pose a barrier to absorption of the chemical. Therefore, it is essential to the present invention that the target tissue is pierced so that a micro-dose of chemical can be used while still providing efficacy.

The reader should appreciate that the term ‘chemical’ used throughout the specification should be given its broadest definition. In one form the chemical being applied is selected from a group containing, but not limited to, insecticides, fertilisers, trace elements, nutrients, inoculants, herbicides (i.e. glyphosate), fungicides, growth regulators, genetic material, hormones, pheromones, or any other form of chemical that can be applied to a target plant to kill the plant or improve health or treat/inhibit/inoculate against a disease, infection or parasitism.

DETAILED DESCRIPTION OF THE ILLUSTRATED AND EXEMPLIFIED EMBODIMENTS

Similar reference characters indicate corresponding parts throughout the drawings. Dimensions of certain parts shown in the drawings may have been modified and/or exaggerated for the purposes of clarity or illustration.

Referring to the drawings for a more detailed description, there is illustrated an apparatus10for delivery of a chemical into a tissue of a target organism, demonstrating by way of examples, arrangements in which the principles of the present invention may be employed. The reader should appreciate that the apparatus10will be primarily described with reference to applying a chemical to the leaf12of a terrestrial plant, however it should be appreciated that the invention is not limited to this particular application and could also be used in relation to an aquatic plant or other organism.

Turning toFIGS.1to3there is illustrated one embodiment of the apparatus10, comprising a body14having a hinge portion16and an applicator portion18. The term applicator portion used throughout the specification means the portion that is used to hold the chemical and apply it to the plant tissue. It should be appreciated by the reader that the hinge portion is still actively involved in the process however the phases are used simply to define different sections of the body14. The applicator portion18in the present embodiment comprise first jaw20, that is configured to oppose second jaw22of the body14. Although the hinge portion16illustrated comprises a curved hinge24that is unitary with the second jaw22, other types of hinged members may be used and the first and second jaws20,22may be separate and joined by way of a separate hinge member (not shown).

The curved hinge24is shaped such that the first and second jaws20,22are biased apart to provide sufficient space for the positioning of a leaf or other plant material between the jaws20,22when at rest. As the jaws20,22are brought together elongate porous piercing elements32incise the leaf12to thereby treat the target plant with the chemical.

The second or lower jaw22includes a lower finger support26on or attached to an outer surface. A foam pad28is located on an inner surface of the second jaw22opposing a foam pad30on or attached to an inner surface of the first jaw20. The foam pads28,30may be over moulded to the respective jaw20or22, or they may be attached by way of an adhesive or may be welded thereto.

As will become clear the foam pad28is preferably a closed cell foam material and is generally uniform. The foam pad30is also constructed from a closed cell foam material however includes openings31to accommodate the elongate porous piercing elements32. The reader will however appreciate that the elongate porous piercing elements32may simply be pushed through the foam pad30to thereby create openings and the openings do not need to be manufactured in the foam pad30prior to use.

In the present embodiment, a tank34is attached to an outer surface of the first jaw20to thereby form a reservoir chamber36, as illustrated inFIG.4, which is configured to hold the chemical for applying to the target plant. The elongate porous piercing elements32are connected to a porous base38, as illustrated inFIG.4. The porous base38is held in position by ribs or support members40.

As further illustrated inFIG.4the lower jaw22includes a latch42for engagement with a cap44, as will be discussed with respect toFIGS.14to19.

FIGS.5and6illustrate the front view of the apparatus10showing the configuration of the opposing foam pads28and30and the elongate porous piercing elements32and base38.FIG.6illustrates how the reservoir chamber36containing the chemical is in fluid communication with the porous base38such that the chemical is able to move in the direction of the broken arrows from within the reservoir chamber36, through the porous base38and porous piercing elements32, such that it can escape from the outer surface of the porous piercing elements32. The skilled addressee will appreciate that the chemical will be presented on or adjacent the outer surface of the porous piercing elements32such that when it pierces the tissue of the target plant the chemical is wiped off thereonto.

The reader will also appreciate that the movement of the chemical may simply rely upon capillary action wherein the chemical is able to flow through the narrow spaces without an external force being applied, however, the tank34may also be pressurised to impel the chemical into the porous piercing elements32. The surface tension of the particular chemical will inhibit it from dripping out of the pores of the porous material.

FIG.7illustrates the tank34and the porous base/piercing elements, collectively referred to as the porous elements32,38, separated from the first jaw20. The porous elements32,38are configured to be positioned within aperture46, such that the elongate porous piercing elements32engage openings31in the foam pad30, or simply impinge upon the foam pad30such that piercing elements32form openings therethrough. The tank34is configured to engage recess48, such that it provides a leak proof seal. The tank34may be welded, glued or otherwise fixed to the first jaw20.

It is envisaged that the porous elements32,38will be constructed from a sintered ceramic, metal, aluminium oxide or silicon carbide material. However other material could be used as the wick to draw the chemical out from within the reservoir chamber36such that it is presented on an outer surface for application to a plant tissue. An intermediate porous member (not shown) may also be included between the reservoir chamber36and porous base38or a passageway or passageways may lead between the reservoir chamber36and porous base38.

FIG.8aillustrates one embodiment of the porous elements32,38, wherein the elongate porous piercing elements32are unitary with the porous base38. The porous piercing elements32include a shaft50that extends outwardly from the base38and a tapered tip52for assisting in the incising of the plant tissue. The tapered tip52may be generally cone shaped having a single curved face as illustrated inFIG.8a, or alternatively the tapered tip52may include generally planar faces54with intermediate cutting edges56and the shaft50may be generally cube shaped. The reader should also appreciate that the shaft may be tapered.

The spacing of the plurality of porous piercing elements32as illustrated inFIGS.8aand8bis approximately 1.5 mm. In this way, the porous piercing elements32are able to pierce plant tissue, however are inhibited from piercing human tissue, due to the proximity of the adjacent porous piercing elements32, if the applicator portion comes into contact with a user's hand or foot.

In use, the tissue of the target plant such as a leaf12, as illustrated inFIGS.9to13b, is positioned between the first and second jaws20,22. The user then applies pressure with their fingers58and thumb60to bring the jaws20,22together against the bias of the hinge24. Upon closing of the first and second jaws20,22the elongate porous piercing elements32piece the leaf12. As the pressure from the user's hand is reduced the jaws20,22spring apart and the apparatus10can be removed from around the leaf12.FIG.10illustrates the holes62that are formed in the leaf12. As the reader will appreciate, the chemical is presented on the outer surface of the porous piercing elements32, such that as they incise the leaf12, some of the chemical is wiped off on the edges of the incisions62.

FIG.13aillustrates the leaf being positioned between the jaws20,22which have been moved toward each other such that the foam pads28,30touch the outer surface of the leaf12. As the jaws20,22are brought closer the foam pads28,30are compressed, as illustrated inFIG.13b, such that the porous piercing elements32extend out from within openings31and incise the leaf12. The reader will appreciate that the leaf12is supported by the foam pad28to assist in the incision of the leaf. Furthermore, the foam pad28is compressible such that depressions64are formed in the upper surface to accommodate the porous piercing elements32. This ensures that the porous piercing elements32pass completely through the leaf12to provide the greatest delivery of chemical to the edges of the incision62.

When not in use the first and second jaws20,22are brought together such that the compressible foam pads abut. A cap44, as illustrated inFIGS.14to19, is then reversibly attached over part of the applicator portion18to thereby hold the jaws20,22together. The cap44inhibits unauthorised tampering with the device and also assists in inhibiting evaporation of the chemical off the porous piercing elements32when not in use.

As illustrated inFIG.14, the cap44includes a front portion66, rearwardly extending sides68,70and an underside72. The underside72includes a hole74, as illustrated inFIGS.18and19, for engagement by the latch42. The latch42acts to hold the cap44in place as illustrated inFIG.15, against unauthorised removal. For instance, a child lock system could be used, such as a double press being required to disengage the latch, or any other type of locking system could be used.

In another embodiment as illustrated inFIGS.20to26the applicator portion18is attached to an end of a handle80, such that in use the one or more porous piercing elements32are configured to be extended downwardly to pierce the plant tissue of a target plant that has a generally prostrate growth habit, as illustrated inFIG.20.

As illustrated inFIG.23, the applicator portion comprises a tapered tank82that frictionally engages a recess84in the end of the elongate handle80. The tapered tank82holds the majoring of the chemical when full and is attached to a support member86. The support member86accommodates the porous base38and porous piercing elements32, such that the porous piercing elements32depend from the base38. A resiliently deformable member88, in one form being a closed cell foam pad, is attached to an underside of the support member86and surrounds the porous piercing elements32. As shown inFIG.22the porous piercing elements32are concealed within the closed cell foam pad88when not in use.

When a user applies downward pressure, as indicated by the solid arrow inFIG.24, the foam pad88is compressed against the leaf12that is resting on the ground90and the porous piercing elements32extend therefrom to pierce the leaf12of the prostrate plant. Once the downward pressure is removed the resiliently deformable foam pad88expands back to its original size which assists to push the leaf12off the porous piercing elements32.

As illustrated inFIGS.25and26, the applicator portion18can be removed from the end of the handle80when the reservoir chamber36is empty. In this way, the same handle80can be reused by simply replacing the applicator portion18or part thereof. A cap (not shown) may cover the underside of the applicator portion18when not in use.

FIGS.27to33billustrate another embodiment of the apparatus10wherein the applicator portion is in the form of a detachable cartridge18. Once empty the detachable cartridge18can be disconnected from the body14and a new cartridge18attached. This means that the handle80can be used multiple times by simply replacing the cartridge18.

In the immediately preceding embodiment, the cartridge18engages a moveable sleeve92that is connected to the body14to thereby hold the cartridge18in place during use. The moveable sleeve92may include a child lock to inhibit unauthorised tampering. As further illustrated in the figures, especiallyFIGS.33ato33b, the sleeve engages catch94as will subsequently be explained.

Turning back toFIGS.27and28, the lower jaw22includes a plurality of grooves96that cooperate with the piercing elements32to assist in the piecing of the leaf. The piercing elements32align the grooves96so that the raised area between the grooves96applies pressure to the leaf surface to assist in the piercing thereof, in a similar fashion to the foam pad as previously discussed. The grooves96allow sideways or lateral misalignment of the jaws20,22, as may occur when a user closes the jaws. The piercing elements32in the present embodiment are surrounded by a circumferential skirt98to inhibit inadvertent contact with the piercing elements32. This circumferential skirt98protects the piercing elements32and also assists in pushing the leaf off the piercing elements32after treatment of the leaf. The body14also includes a spacer100to maintain a predetermined distance between the jaw20,22when in the closed position, to thereby inhibit the piercing elements32from impinging upon the sides of the plurality of grooves96, which may damage the piercing elements32or lead to leakage therefrom.

As illustrated inFIG.29, the moveable sleeve92includes an engagement member102for engagement with the catch94, as will be discussed with respect toFIGS.33ato33b.FIG.29further illustrates the configuration of the connection between the cartridge18and the body14, wherein the cartridge18has a tongue104that engages with a cooperatingly shaped end106of the body14. The tongue104and end106are held in engagement by the moveable sleeve92. By moving the moveable sleeve92in a rearward direction the cartridge18can be detached from the handle80. A biased latch107is illustrated inFIG.30that acts to push the tongue104upwardly against end106when the moveable sleeve92is in a forward position. As the moveable sleeve92is moved rearwardly the biased latch107is able to be moved downwardly or outwardly to allow the passage of the tongue104when attached or detaching the cartridge18.

As illustrated inFIGS.30and31, the cartridge18may comprise a tank34that is welded or glued to a base frame108having a cooperatingly shaped upstand110, a porous member32/38and a circumferential skirt98. The base frame108includes a hole112extending therethrough that is shaped to accommodate the porous base38therein. The porous base38includes recesses in an upper side to facilitate the movement of fluid from the tank34to the piecing elements32. As further illustrated inFIGS.30and31, a removable film116may be attached over the outer edge of the circumferential skirt98to inhibit leakage or tampering prior to use.

FIGS.32ato32cillustrate the cartridge18in isolation from the body14. The Inventor envisages that a multipack of cartridges18would be provided to a user, in a similar fashion to disposable razors, wherein the user would be able to replace the cartridge18when all the chemical within the tank34has been applied. In some embodiments, the tank34would be constructed from clear material or at least have a transparent window through which the user can assess to amount of chemical remaining within the tank34.

Turning toFIGS.33aand33bthere is illustrated a locking means by which the apparatus10is held in a closed positioned when not in use. The reader should appreciate that having the apparatus closed when not is use reduces that chance of a child coming into contact with the piercing elements32and also means that piercing elements32will be inhibited from drying out during storage.

FIG.33aillustrates the apparatus10in an open position wherein it can be used in a fashion as previously discussed. When the user wants to close the apparatus10for storage or between uses, they apply pressure so that the jaws20,22are brought together and the circumferential skirt98abuts the upper surface of the lower jaw22. The moveable sleeve92is then slid rearwardly whereby the engagement member102of the moveable sleeve92engages the catch94on the body14. This will thereby retain the apparatus10in the closed position until the moveable sleeve92is slid forward. Although not illustrated the cooperating engagement member102and catch94may include a hook or ridge that acts as a child lock to inhibit a child from sliding the moveable sleeve92forward, but which under greater force will disengage to permit movement of the moveable sleeve92.

As the reader should appreciate, when the moveable sleeve92is slid rearwardly such that the engagement member102engages the catch94, the join between the tongue104and end106is not affected. To remove the cartridge18the moveable sleeve92must be moved rearwardly when the jaws20,22of the apparatus10are open.

FIGS.34a,34billustrate one embodiment of the elongate porous piercing elements32and porous base38wherein the piercing elements32are of uniform or generally uniform length. In another embodiment, as illustrated inFIG.35a,35bthe piercing elements32aand32bare of different lengths. The Inventor envisages that having a plurality of porous piercing elements or spikes of different heights may assist in the piercing of leaves of different thicknesses, widths or lengths.

FIGS.36to42billustrate still another embodiment of the apparatus10which includes a valve pin118, and a membrane120, which is positioned within the tank34and acts to seal the tank34prior to use. The valve pin118may also provide venting of the tank34as the fluid level drops.

As illustrated inFIG.39the valve pin118includes a head122, aperture124, grooves126and vent hole128. Venting occurs with the exterior of the tank34through aperture124and vent hole128.

The valve pin118is movably held within engagement member130and is biased outwardly so that when the jaws20,22are open the valve pin118seals against the membrane120. The engagement member130may comprise or include an elastomeric sheath that is overmoulded with a circumferential skirt whereby the skirt is compressed by the pin when the jaws are closed and provides the biasing to move the valve pin118outwardly when the jaws are open.

FIGS.40aand40billustrated the apparatus10prior to first use wherein the membrane120is intact. Upon squeezing of the hinged portion16to treat a leaf, as illustrated inFIGS.41a,41b, the valve pin118pierces the membrane120and allows the chemical to flow through groove/s126into the porous elements38,32, as indicated by the arrow.

When in the locked position, as illustrated inFIGS.42a,42b, the valve pin118retract under bias into a position where the hole in the membrane120is blocked and the chemical is inhibited from flowing through the hole in the membrane120created by the valve pin118. The Inventor envisages that this will inhibit leakage during storage.

FIGS.43to47illustrate an alternate upright apparatus10that includes a biased support140. When treating weed having a prostrate growth habit it is important that the amount of chemical that comes into contact with the underlying plants, such as blades of grass, is minimised. In the present embodiment, the biased support140includes a main body142that is located intermediate of the handle80and applicator portion18, a base144having apertures146that correspond vertically to the location of the porous piercing elements32, a shaft148that engages aperture150in the main body142, a biasing spring152surrounds the shaft148, and a split ring154that engages the top156of the shaft148.

In use the base144is slid under the leaf of a plant to be treated. Downward pressure is then applied by the user to the handle80, which causes the shaft148to retract into or through the main body142, thereby causing the porous piercing elements32to push through the leaf and apertures146. As the reader will appreciate the base144provide support for the underside of a leaf being treated while minimising the amount to chemical coming into contact with the underlying plants, such as the lawn.

FIGS.48to60illustrates another embodiment of the apparatus10wherein the applicator portion is in the form of a detachable canister18. The tank34of the present embodiment slidably engages a recess160in the body14. The detachable canister18is held within the recess160by deflectable clips162,164that are biased outwardly and sidewardly engage respective slots166in opposite sides of the body14. In this way, the canister18can be attached to and removed from the handle14, such as when it needs replacing, as illustrated inFIGS.52to55.

As illustrated inFIGS.50,55and57, the canister18comprises the tank34that forms the reservoir chamber36, and a manifold168that is in fluid communication with the porous base38and piercing elements32, by way of passageway170. The canister18is attached to the manifold168by joiner172. The reader should appreciate that the joiner172may be in the form of a separate intermediate member or the canister18may be attached directly to the manifold168by way of welding, gluing, a clip or cooperating threads. The reader should also appreciate that the manifold168forms the upper jaw20of the apparatus10.

Two flap valves174,176, are positioned along or adjacent the passageway170to control the flow of fluid therealong. The flap valves174,176, may be constructed from rubber, elastomer, fluoroelastomer or any other form of suitable material. The term ‘valve’ should be understood to include glands or weep holes that are able to be closed.

As further illustrated inFIG.50, plunger178is positioned within the tank34and is acted upon by actuator/pump180, which is located along passageway170, to thereby replenish the chemical within passageway170to ensure adequate chemical for the porous base38and piercing elements32. The actuator/pump180is biased outwardly by way of spring182. The second or lower jaw22includes a protrusion184that is configured to push the actuator/pump180inwardly against the bias of the spring182, when the jaws20,22are pushed together, as illustrated inFIG.57.

The tank34includes an opening184to permit movement of air into the reservoir chamber36rearwardly of the plunger178, to inhibit the formation of a vacuum behind the plunger178, which would adversely affect to operation of the apparatus10.

As illustrated inFIGS.50and58-60, the porous base38includes a depression186to allow operation of the flap valve176. The reader should however appreciate that the valve176could be positioned at a distance from the porous base38and therefore the depression186would not be required.

FIGS.61to66illustrate still another embodiment, that includes porous piercing spikes each including a generally solid base200and a porous tip202. The porous tip202may be press fitted or heat welded onto the solid base200. The solid bases200may be formed on an underside of the manifold168or attached thereto. An elastomeric pad204is glue or otherwise attached to the manifold and includes one-way glands or valves206that are formed around each solid base200. In this way when the gland or valve206opens the porous tip202will be in fluid communication with the reservoir36and can receive chemical thereinto. In this way, the chemical is able to flow over and into the porous tip to thereby inhibit dripping and provide a store of chemical during use to thereby improve the efficacy of the device.

The present invention also includes a leaf ejector plate208, which is configured to push the leaf off the spikes32. Furthermore, the leaf ejector plate208incorporates a piston210and return spring212for pumping the chemical into the passageway170, as previously discussed.

During the piercing action the chemical is displaced from the manifold168by the piston210and flows out through the glands206and onto the spike32, which is coated with some of the chemical being absorbed into the porous tip202. The porosity of the tips202helps to distribute the chemical evenly and also provides surface pockets that can hold chemical and readily transfer it to the perforations in the leaf.

In another embodiment, the piercing element or elements may be constructed sustainably from the chemical that is to be applied to the plant, wherein the piercing element or elements, or a part thereof, are dissolvable or otherwise liquefiable, by an activating liquid or substance, whereby the chemical is thereby in a form that can be applied to the plant tissue for absorption thereof.

The device therefore may take the form of any of the above embodiments or other embodiments, for applying a chemical to a plant tissue, however the chemical reservoir may be filled with the activating liquid or substance that can be applied to the piercing element or elements just prior to piecing of the plant tissue to initiate, for a desired period of time, a chemical reaction or other change of state causes the generally solid piercing element or elements to dissolve or liquefy. The reader should appreciate that the chemical reaction or liquefaction is preferably only for a short period of time and then is discontinued to pervert the continued liquefaction of the piercing element or elements. For instance, in the presence of water the piercing element or elements may dissolve and then when the piercing element or elements are dry they stop dissolving and remain in their generally solid form until water is again applied to the piercing element or elements.

In one embodiment, the piercing element or elements may be in a crystallised form that is dissolvable or otherwise liquefiable by a liquid or plant enzyme or as a result of chemical reaction or change of state in the presence of an activating liquid or substance.

Therefore, the piercing element or elements are in an inactive state prior to use and then when a user wishes to apply the chemical to a plant tissue the activating liquid or substance is applied to the piercing element or elements to cause partial or surface liquefaction to enable application of the chemical to the plant tissue.

In another embodiment, liquefaction of the piercing element or elements is caused by a plant enzyme or other plant originating substance acting on the piercing element or elements to start the liquefaction or dissolving process, whereby the chemical is in a form that can be taken up or absorbed by the plant.

Therefore, as the reader will appreciate, once the piercing element or elements is/are dissolved or liquefied, the chemical can be introduced into and absorbed by the plant tissue to thereby treat the target plant.

The activating liquid or substance may therefore be applied to the piercing element or elements from the chemical reservoir or may be of a plant originating substance or the activating liquid may be applied directly to the plant tissue, such as the leaf, prior to use of the piercing element or elements.

In the embodiment where the activating liquid is contained within the chemical reservoir, the activating liquid in one form is water that is applied to the piercing element or elements, to causes an outer layer to be liquefied so that it can be applied to the plant tissue as the piercing member or members pierce the plant tissue.

The piercing element or elements may be substantially formed from a crystallised glyphosate (N-(phosphonomethyl)glycine).

The dissolvable piercing element or elements may include a carrier or bonding agent that solidifies or holds the chemical and allows for it to be liquefied under a desired condition.

The carrier may be in the form of an inert matrix wherein the chemical to be applied to the plant is held within the matrix and dissolved from therewithin. In another embodiment, the matrix may be activated by the activation liquid or substance wherein the matrix is configured to hold the chemical until it is activated, whereupon the matrix releases the chemical at a desired rate.

The reader should appreciate that the phrase porous piercing member or element used throughout the specification may also refer to a piercing element that may be penetrated by an activating liquid or substance to thereby liquefy or partly liquefy the chemical to allow for it to be applied to the plant tissue.

The piercing element or elements may be at least partly porous or may be generally solid but which allows an activating liquid or chemical to penetrate thereinto or dissolve a surface layer.

The skilled addressee will now appreciate the advantages of the illustrated invention over the prior art. In one form the invention provides an apparatus that delivers a chemical to a plant tissue while minimising the risk to the surrounding environment. The porous piercing elements of the present invention contain at least a portion of the chemical and therefore little is applied to the outer surface of the target plant during delivery. In this way, the potential for wash-off of the chemical is reduced since the chemical is applied to interior of the target plant, where it is likely to be of the greatest efficacy.

The apparatus facilitates the impregnation or introduction of the chemical into the tissue of the target organism. This is in contrast to many of the currently available devices that apply the chemical to the exterior surface of the tissue. The chemical is impregnated or introduced into the target organisms to thereby improve the efficacy of the applied chemical, at lower doses than achieved with conventional devices and methods of application, which also minimises exposure of non-target animals or plants to the chemical. The illustrated invention therefore provides commercial choice or at least gives the public a useful alternative. Various features of the invention have been particularly shown and described in connection with the exemplified embodiments of the invention, however it must be understood that these particular arrangements merely illustrate the invention and it is not limited thereto. Accordingly, the invention can include various modifications, which fall within the spirit and scope of the invention.