DK201370467A - Weed wiper apparatus - Google Patents

Abstract

A weed wiper system includes a frame including an attachment arrangement for attachment to a vehicle and a plurality of wiper elements distributed across the width of the frame. Each wiper element includes an absorbent material and a fluid outlet for supply of fluid to the absorbent material. Such that fluid is wiped onto weeds as the apparatus moves over them. The system may include sensors and controllable elements, enabling control of the moisture content of the wiper elements. A positioning system may be included and steering instructions may be provided to a driver. The frame height may be adjustable, and side frames may be attached providing an increased application width. A suspension system may be provided.

Description

WEED WIPER APPARATUS FIELD OF THE INVENTION

The invention relates to weed wipers for application of chemicals to weeds, and to associated methods and systems.

BACKGROUND TO THE INVENTION

There are many known types of apparatus for applying liquid chemicals, such as herbicides, to weeds or other undesirable plants. These include apparatus relying on wipe-on placement of the chemical. Such apparatus includes one or more wiper elements which can be comprised of rope wicks or fabric / sponge covered tubes, pipes or the like. The laughter can, for example, comprise a length of plastic material tube, (e.g. PVC) having small perforations or openings along its length with the tube being covered by felt, carpet, sponge or similar material.

New Zealand patent specification 196493 discloses a wipe-on placement applicator comprising a frame (or plurality of frames) which is / are mountable on a tractor or other vehicle such that the frame (s) can be moved over the weeds / plants to which herbicide is to be applied. Each wiper element is composed of wick rope and a plurality of parallel ropes are mounted across the frame (s) such that the ropes are at an angle to the direction of travel of the frame (s). It is claimed that more effective application of herbicide is achieved because of the angled configuration of the wiper elements as the ropes wipe along the weeds rather than intersect the weeds at right angles.

The Applicant's NZ248902 proposed improvements in weed wipers, in which an absorbent wool based material was used to hold the chemical. This provided improved performance by limiting undesirable dripping of chemical from the weed wiper and effective wiping of chemical onto weeds. The entire contents of NZ248902 are hereby incorporated by reference herein.

The Applicant has found that further improvements are possible.

Reference to any prior art in this specification does not constitute an admission that such prior art forms part of the common general knowledge.

It is an object of the invention to provide an improved weed wiper apparatus and / or system and / or method, or at least to provide the public with a useful choice.

SUMMARY OF THE INVENTION

In a first aspect the invention provides a weed wiper system including: a frame including an attachment arrangement for attachment to a vehicle; a plurality of wiper elements distributed across the width of the apparatus, each wiper element including an absorbent material and a fluid outlet for supply of fluid to the absorbent material, the absorbent material being supported by the frame and arranged to wipe fluid onto weeds as the apparatus moves over them; a chemical tank for holding chemical to be applied; a feed network of feed tubes for feeding chemicals from the chemical tank to the fluid outlets of the wiper elements, the feed network including a plurality of controllable elements for controlling feed rates to the individual wiper elements; a sensor configured to monitor moisture content in the absorbent material of each wiper element; a controller configured to control the controllable elements to maintain the moisture content of the absorbent material of each wiper element within a desired range.

Preferably the system includes a positioning system configured to determine in real time a position of the weed wiper apparatus or a vehicle to which it is attached.

Preferably the system includes a display unit, controlled by the controller, configured in real time to provide instructions to a driver based on the gathered position information.

Preferably the system includes one or more additional sensors for monitoring one or more of: flow rate and a state of a controllable element.

Preferably the system includes memory for storing gathered data.

In a second aspect the invention provides a weed wiper system including: a weed wiper apparatus including a frame including an attachment arrangement for attachment to a vehicle; a plurality of wiper elements distributed across the width of the apparatus, each wiper element including an absorbent material and a fluid outlet for supply of fluid to the absorbent material, the absorbent material being supported by the frame and arranged to wipe fluid onto weeds as the apparatus moves over them; a chemical tank for holding chemical to be applied; a feed network of feed tubes for feeding chemical from the chemical tank to the fluid outlets of the wiper elements; a positioning system configured to determine in real time a position of the weed wiper apparatus or a vehicle to which it is attached; a controller configured to receive position information from the positioning system; and a display unit, controlled by the controller, configured in real time to provide instructions to a driver based on the gathered position information.

Preferably the instructions are steering instructions and the controller is configured to determine the instructions to be displayed based on an area to which chemical has already been applied and the current position of the weed wiper apparatus.

Preferably the system includes a sensor configured to monitor moisture content in the absorbent material of each wiper element; and a controller configured to control the controllable elements to maintain the moisture content of the absorbent material of each wiper element within a desired range.

In a third aspect, the invention provides a weed wiper apparatus including: a chassis including an attachment arrangement for attachment to a vehicle; at least one wiper element mounted on or to the chassis, each wiper element including an absorbent material and a fluid outlet for supply of fluid to the absorbent material, the absorbent material being arranged to wipe fluid onto weeds as the apparatus moves over them; a first height adjustable support arrangement configured to support the chassis at an adjustable height above the ground; at least one side frame connected at an inner end thereof to the chassis and extending to the side of the chassis; a second height adjustable support arrangement configured to support an outer end of the side frame at an adjustable height above the ground; at least one further wiper element mounted on or to the side frame, each further wiper element including an absorbent material and a fluid outlet for supply of fluid to the absorbent material, the absorbent material being arranged to wipe fluid onto the weeds as the apparatus moves over dem.

Preferably the side frame is connected to the chassis by a hinged connection.

Preferably the apparatus includes a side frame support arrangement, wherein the side frame is configured to fold about the hinged connection to a stowed position in which it is supported by the side frame support arrangement.

Preferably the attachment arrangement includes an adjustable height element, configured to enable adjustment of a towbar height relative to the vehicle.

In a fourth aspect, the invention provides a weed wiper apparatus including: a chassis including an attachment arrangement for attachment to a vehicle; at least one wiper element mounted on or to the chassis, each wiper element including an absorbent material and a fluid outlet for supply of fluid to the absorbent material, the absorbent material being arranged to wipe fluid onto weeds as the apparatus moves over them; a first height adjustable support arrangement configured to support the chassis at an adjustable height above the ground; at least one side frame connected at an inner end thereof to the chassis and extending to the side of the chassis; at least one further wiper element mounted on or to the side frame, each further wiper element including an absorbent material and a fluid outlet for supply of fluid to the absorbent material, the absorbent material being arranged to wipe fluid onto the weeds as the apparatus moves over they, where an inner part of at least one of the further wiper elements overlaps with an outer part of at least one of the first wiper elements, such that there is no gap in chemical application between the first and further wiper elements as the apparatus moves over the ground.

In a fifth aspect, the invention provides a weed wiper apparatus including: a chassis including an attachment arrangement for attachment to a vehicle; at least one wiper element mounted on or to the chassis, each wiper element including an absorbent material and a fluid outlet for supply of fluid to the absorbent material, the absorbent material being arranged to wipe fluid onto weeds as the apparatus moves over them; a support arrangement configured to support the chassis above the ground, while the support arrangement includes one or more suspension elements.

Preferably the support arrangement includes a torsion bar suspension element.

Preferably the support arrangement is height adjustable.

Preferably the apparatus includes an adjustment element configured to cause rotation of the torsion bar at a central point in order to adjust the chassis height. LETTER DESCRIPTION OF THE DRAWINGS

The invention will now be described by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows the prior art weed wiper of NZ248902;

Figure 2 shows the wiper element of the wiper of Figure 1;

Figure 3 shows a weed wiper system according to one embodiment;

Figure 4 is a plan view of a weed wiper according to a further embodiment;

Figure 5 is a front view of the weed wiper of Figure 4;

Figure 6 is a side view of the weed wiper of Figure 4; spirit

Figure 7 is a perspective view of the weed wiper of Figure 4.

DETAILED DESCRIPTION

The wiper element of the present invention may be incorporated into or as part of a frame arrangement which may be attached directly or indirectly to a vehicle such as a tractor, farm truck or ute, ATV (all terrain vehicle) or RTV (rough terrain) Vehicle). Generally the frame will be so mounted that it can be adjusted in height relative to the ground over which it travels.

Liquid chemicals such as herbicides will be held in one or more tanks or containers which can either be mounted on the vehicle or supported by the frame (s). Suitable plumbing enables the chemical to flow via a supply line or lines to individual wiper elements or into a header or plurality of headers which in turn feed the wiper elements. The chemical can flow by either gravity feed or by pressurized delivery means.

Figure 1 shows the weed wiper 10 of NZ248902. In the drawings the wiper applicator 10 is shown including an elongate rectangular shaped main frame 11 having leading and trailing members generally indicated at A and B in Figure 1. A number of skids or wheels may be attached to this main frame 11 to hold the frame and wiper elements at a desired level above the ground, such that frame 11 can be pulled over the ground but spaced therefrom. The height of the frame above the ground may be adjustable.

The leading side member A of the frame 11 can be coupled to an attachment arrangement or mounting whereby the frame is mountable to a vehicle. The apparatus may be suspended below a support frame which is coupled to, or formed with, a tow bar or tow frame. This tow bar / frame has a hitch for removable coupling to the vehicle. A tank can be carried by the support frame. In a preferred form the tank incorporates a pump and filter arrangement. A power supply (battery) for operation of the pump can also be mounted with the tank or else power can be derived from the vehicle. In some embodiments the tank may be carried on the vehicle and connected to the weed wiper by a suitable conduit. A plurality of wiper elements 15 extend between the front and rear longitudinal members A and B of frame 11. If the frame 11 is generally of rectangular shape a shorter wiper element 15 'is located at diagonally opposite corners of the frame 11 to extend between the respective longitudinal member A or B and an end transverse member C of frame 11. In the preferred form of the invention as illustrated wiper elements 15 and 15 'are of a gently curved configuration.

In the present invention, the structure of the wiper elements may be described in NZ248902. A general each wiper element includes an absorbent material supported by the frame and one or more fluid outlets for release of fluid into the absorbent material. As shown in Figure 2, which also relates to the weed wiper of NZ248902, the wiper element may include a sleeve 17 of absorbent material supported on a support tube 16 which is attached to the frame 11. A further tube 22 also passes through the sleeve 17, with a connector and T junction indicated generally at 24 inserted at one end of tube 22 while the other end of tube 22 (not shown) is closed. The tube 22 has a number of flow outlets allowing fluid to pass from the tube 22 into the absorbent material. The T junctions 24 are connected to supply lines 25 which are fed from a main supply line 26 which leads to the pump / tank arrangement used for supplying chemicals. As a consequence chemical can flow into tubes 22 and exit through the bores so as to wet the inside of the tubular covering 17. Due to the absorbent nature of the covering the chemical migrates through to the exterior thereof and as the wiper element brushes over weeds and undesirable plants the chemical is applied thereto.

In the preferred arrangement of a wiper applicator chemical is supplied to the wiper elements under pressure and more particularly a pressure in the range of 0-1.5 bar but more preferably in the region of 7-10 psi. A leading edge of the frame 11 may be formed with a number of formations, such as sharp edges or points, abrasive regions or the like designed to penetrate or bruise the weeds as the frame passes over them. This improves the efficacy of the weed killer applied by the wiper elements, since it can easily penetrate the surface of the weed.

The moisture content of the absorbent material is preferably monitored and moisture applied to the absorbent material so as to maintain the moisture content within a desired range. In particular, in some embodiments one or more strain gauges or other sensors may be used to monitor the weight of each wiper element. As the moisture content of the absorbent material rises, so does its weight. If the apparatus is towed the wiper elements tend to move up and down, for example as the apparatus moves over bumpy ground. This affects the weight measurement, but measurements can be averaged over time to cater for this, or an accelerometer may be used to cancel out forces occurring from the wiper elements' movement up and down thus leaving a resultant vector acting in the same axis as gravity .

Alternatively, moisture sensors may be installed in each wiper element to measure a moisture level in the absorbent material.

Based on the measured moisture content, a controller is configured to control one or more valves or other controllable elements in the feed network in order to increase or decrease fluid flow to the various wiper elements, as appropriate to maintain moisture at the desired level.

The present invention thus provides a wiper element which results in better controlled delivery of chemical to the wiping surface and thus largely overcomes the problems associated with known wiper elements. In addition to better control and the market reduction in the adverse effects of uncontrolled drip of chemical from the wiper element the present invention leads to more efficient use of chemical resulting in lower chemical usage.

Figure 3 is a schematic diagram showing the control arrangement for the weed wiper. Chemical fluid is supplied from a tank 100 via a feed network 101 (shown in heavy line) to the plurality of wiper elements 102. Each wiper element 102 includes a moisture measurement device 103, which may be a moisture sensor or weight sensor as described above. . The moisture measurement devices 103 are connected to a communications line, such as a serial bus 105 for communicating data to a controller 106. A number of controllable elements 107, such as valves or the like, are provided in the feed network 101. valves 107 are capable of controlling flow to the individual wiper elements 102. The valves 107 are linked by a control line 108 to the controller 106. Thus, the controller 106 receives moisture content information in the individual wiper elements 102 over communications line 105 and controls the valves 107 in order to increase or decrease flow to the individual wiper elements as necessary in order to maintain wiper element moisture within a desired range.

Optionally, a number of flow meters or pressure sensors 110 may also be provided in the feed network, configured to measure / predict fluid flow to the individual wiper elements 102. Flow meters measure the flow through the tube, while pressure sensors measure the pressure within the tube. Flow information can be deduced from the pressure data and knowledge of the flow network. These flow meters or pressure sensors communicate data to controller 106 over communication lines 112. A main valve 114 and main flow meter 115 may also be provided to control and measure flow from the tank 100 into the feed network 101. These may communicate with controller over lines 116, 117.

In some embodiments a positioning system 120 may also be provided. The positioning system may be a global positioning system (GPS) device. This allows comprehensive information on the working of the apparatus to be gathered, and also allows instructions to be given to the driver, as will be discussed in detail below. A display 121 is also provided, and assists in providing instructions to the driver. A user input device 122 such as a keypad or touch screen allows the user to enter information such as the desired moisture range, chemical name or type, or any other desired information.

Memory 123 allows data collected by the controller to be stored. Communications port 124 allows data to be transferred to another device, for example for integration with farm management software, or to produce reports.

The controller maintains information on the area covered by the weed wiper system. If the system is moved around a field or other area the positioning system provides position information to the controller. This information, together with knowledge of the position of the weed wiper relative to the positioning system and knowledge of the width of the weed wiper allows the controller to determine the area already covered. This also allows the controller to instruct the driver to steer appropriately, for example to slightly overlap with the area already covered. The instructions can be issued to the driver in any suitable form, but are preferably displayed in visual form on display 121. The display may simply instruct a driver to steer to the right or left. A horizontal bar may be displayed, indicating to the user the degree of steering needed, as well as the direction. The display 121 may be a screen, or simply a number of small lights, LEDs or the like.

The system is also configured to collect data when the weed wiper is used. For example, the system can collect data on the area covered, date, chemical used, amount of chemical applied, application rate etc. This data can be used in many different ways.

The system allows weed treatment information to be gathered for improved traceability. It is possible to measure and store data on how much chemical has been applied, on what dates and to which areas of the farm. Further, this data can be monitored over time to provide information on weed infestation, chemical budgeting etc.

The amount of chemical applied is directly related to the weed population, because chemical is applied only to the weeds and is provided to the wiper elements only when their moisture level drops. If a small amount of chemical is used, the weed population is small. If a larger amount of chemical is used the weed population is larger. The amount of chemical applied can therefore be correlated with the gathered position information to provide information on the geographical distribution of weeds. This information can be monitored from year to year, which provides information on the effectiveness of the weed management program, as well as other trends.

The data on application volumes or rates can also be used in chemical budgeting. For example, a farmer may base chemical purchasing decisions on the chemical data for the last year, or the last several years and trends in weed population or chemical usage. This can also take into account the area to be treated etc.

Application rates may be monitored directly by flow meters. Alternatively, application rates may be monitored by storing information related to the valves 107. If the valves are wide open, flow rates will be high; If the valves are only half open, flow rates will be lower. This information can be correlated with known information on the feed network, feed pressure etc to provide application rate information acceptable for many purposes. Different rates or volumes applied by the different wiper elements can be measured and stored separately.

The interpretation of data may be automated through any suitable farm management software.

Figures 4 to 7 show a further embodiment of weed wiper 200. Any of the control and fluid feed systems described above may be used in this embodiment. For clarity the fluid feed network is not shown in these drawings.

The weed wiper 200 includes a chassis 201 configured for attachment via towbar 202 and hitch 203 to a towing vehicle. The chassis 201 includes a main frame 205 on which wheels 206 are mounted, via a suspension system 207. A fluid tank 208 may be mounted on the main frame 205.

The chassis also includes a central wiper framework 210. Wiper elements 211 are mounted in the central wiper framework 210, and each wiper element 211 may be discussed above.

The leading edge 212 of the central wiper framework 210 may be formed as a relatively sharp edge, in order to bruise the weeds before chemical is applied.

The weed wiper 200 may also include side wiper frameworks 214. Preferably the side wiper frameworks 214 are offset either in front of (as shown) behind the central wiper framework 205. A number of wiper elements 215 are mounted in each side wiper framework 214 In the embodiment shown, the side wiper framework is positioned relative to the central frame such that an inner wiper element 216 in each side wiper framework 214 overlaps slightly with an outer element 217 in the central wiper framework. This ensures full coverage application of chemical, with no gap between the central wipers and side wipers.

Each side wiper framework 214 is supported at an outer end by a wheel 220 and at an inner end by a connection 221 to the central framework 205. Preferably, this inner connection 221 is a hinged connection, such that the side wipers can be folded from the extended position shown in Figures 4 to 7 to a stowed position in which the side wipers lie against supports 222. Cooperating connectors 223, 224 may be provided on the side wiper frameworks 214 and the supports 222 in order to retain the side wipers in the stowed position. In the stowed position the width of the wiper 200 is essentially the width of the central wiper framework 210, because the side wipers are folded up. This allows the wiper to be driven through gates, on roads etc with the wipers folded up. The wipers can then be folded down for chemical application. In one embodiment the weed wiper 200 may have a total width around 6 meters in the extended position, and around 2.4 meters with the side wipers folded up.

The front edge 225 of each side wiper may be formed as a relatively sharp edge to bruise weeds before application of chemical.

The height of the weed wiper 200 above the ground surface during use may be adjusted as follows.

The towbar 202 includes a height adjuster 227 (Figure 6). The height adjuster includes a bar 228 that slides within a fixed tube 229. The relative positions of the bar 228 and tube 229 can be fixed by a removable pin engaged in holes 230 in the tube and bar. This mechanism allows the drawable height to be adjusted both for the height of a towing fixture on a towing vehicle and for the desired working height of the weed wiper 200.

The height of the chassis 201 may be adjusted by raising or lowering the wheels 206 relative to the chassis 201. This adjustment is driven by any suitable actuator, whether manual or automatic. In the embodiment shown a crank handle 232 is provided. Rotation of the crank handle applies a rotational force to torsion bar 233, which is mounted to the chassis 201 using any suitable bearings. As shown in Figure 6, the crank rod 234 (which has a threaded end) passes through a nut 235 mounted on an arm 236. The arm 236 is mounted to the torsion arm 233. Thus, rotation of the crank rod 234 drives the arm 236, thereby driving rotation of the torsion bar 233.

The wheels are mounted on arms 238, with fixed mounts 239 to the torsion bar 233. Rotation of the torsion bar, driven by the crank handle 232, therefore raises or lowers the wheels 206 relative to the chassis 201.

The torsion bar also provides a suspension system that helps the wiper 200 pass smoothly over bumps or holes. With the center point of the torsion bar fixed in position by the nut 235, the ends of the torsion bar can twist relative to the center. This provides some flex and thereby allows the wheels to move relative to the chassis, to a small degree, to absorb bumps etc. Other types of suspension system may be suitable in some embodiments.

Each outer wheel 220 may be mounted to its respective side wiper framework 214 by a height adjustable mount 240. In the embodiment shown, the height-adjustable mount 240 includes a bar 241 mounted at a pivot point 242 to the frame 214, with a releasable pin 243 allowing the bar 241 to be fixed at different positions relative to an adjustment strut 244.

The hinged connection 221 is preferably not fixed in the deployed position. This allows natural movement between the chassis 201 and side wipers 214 as the weed wiper moves mover the ground.

In addition to the sensing and control systems discussed above, the embodiment of Figures 4 to 7 may use sensors in the suspension and height adjustment system.

For example, strain or pressure sensors may provide information on weight, which will depend on the moisture content of the wiper elements and the fluid level in the tank.

While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in detail, it is not the Applicant's intention to limit or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of the Applicant's general inventive concept.

Claims (17)

1. A weed wiper system including: i. a frame including an attachment arrangement for attachment to a vehicle; ii. a plurality of wiper elements distributed across the width of the apparatus, each wiper element including an absorbent material and a fluid outlet for supply of fluid to the absorbent material, the absorbent material being supported by the frame and arranged to wipe fluid onto weeds as the apparatus moves over them; iii. a chemical tank for holding chemical to be applied; iv. a feed network of feed tubes for feeding chemical from the chemical tank to the fluid outlets of the wiper elements, the feed network including a plurality of controllable elements for controlling feed rates to the individual wiper elements; v. a sensor configured to monitor moisture content in the absorbent material of each wiper element; vi. a controller configured to control the controllable elements to maintain the moisture content of the absorbent material of each wiper element within a desired range.

2. A system as claimed in claim 1 further including a positioning system configured to determine in real time a position of the weed wiper apparatus or a vehicle to which it is attached.

3. A system as claimed in claim 2 including a display unit, controlled by the controller, configured in real time to provide instructions to a driver based on the gathered position information.

4. A system as claimed in claim 1 further including one or more further sensors for monitoring one or more of: flow rate and a state of a controllable element.

5. A system as claimed in any preceding claim further including memory for storing gathered data.

6. A weed wiper system including: a weed wiper apparatus including i. a frame including an attachment arrangement for attachment to a vehicle; ii. a plurality of wiper elements distributed across the width of the apparatus, each wiper element including an absorbent material and a fluid outlet for supply of fluid to the absorbent material, the absorbent material being supported by the frame and arranged to wipe fluid onto weeds as the apparatus moves over them; iii. a chemical tank for holding chemical to be applied; iv. a feed network of feed tubes for feeding chemical from the chemical tank to the fluid outlets of the wiper elements; a positioning system configured to determine in real time a position of the weed wiper apparatus or a vehicle to which it is attached; a controller configured to receive position information from the positioning system; and a display unit, controlled by the controller, configured in real time to provide instructions to a driver based on the gathered position information.

7. A system as claimed in claim 6 wherein the instructions are steering instructions and wherein the controller is configured to determine the instructions to be displayed based on an area to which chemical has already been applied and the current position of the weed wiper apparatus.

8. A system as claimed in claim 6 or 7 including a sensor configured to monitor moisture content in the absorbent material of each wiper element; and a controller configured to control the controllable elements to maintain the moisture content of the absorbent material of each wiper element within a desired range.

9. A weed wiper apparatus including: i. a chassis including an attachment arrangement for attachment to a vehicle; ii. at least one wiper element mounted on or to the chassis, each wiper element including an absorbent material and a fluid outlet for supply of fluid to the absorbent material, the absorbent material being arranged to wipe fluid onto weeds as the apparatus moves over them; iii. a first height adjustable support arrangement configured to support the chassis at an adjustable height above the ground; iv. at least one side frame connected at an inner end thereof to the chassis and extending to the side of the chassis; v. a second height adjustable support arrangement configured to support an outer end of the side frame at an adjustable height above the ground; vi. at least one further wiper element mounted on or to the side frame, each further wiper element including an absorbent material and a fluid outlet for supply of fluid to the absorbent material, the absorbent material being arranged to wipe fluid onto weeds as the apparatus moves over them.

10. An apparatus as claimed in claim 9 wherein the side frame is connected to the chassis by a hinged connection.

11. An apparatus as claimed in claim 10 including a side frame support arrangement, wherein the side frame is configured to fold about the hinged connection to a stowed position in which it is supported by the side frame support arrangement.

12. An apparatus as claimed in claim 9, 10 or 11 wherein the attachment arrangement includes an adjustable height element, configured to enable adjustment of a towbar height relative to the vehicle.

13. A weed wiper apparatus including: i. a chassis including an attachment arrangement for attachment to a vehicle; ii. at least first one wiper element mounted on or to the chassis, each wiper element including an absorbent material and a fluid outlet for supply of fluid to the absorbent material, the absorbent material being arranged to wipe fluid onto weeds as the apparatus moves over them; iii. a first height adjustable support arrangement configured to support the chassis at an adjustable height above the ground; iv. at least one side frame connected at an inner end thereof to the chassis and extending to the side of the chassis; v. at least one further wiper element mounted on or to the side frame, each further wiper element including an absorbent material and a fluid outlet for supply of fluid to the absorbent material, the absorbent material being arranged to wipe fluid onto weeds as the apparatus moves over them, wherein an inner part of at least one of the further wiper elements overlaps with an outer part of at least one of the first wiper elements, such that there is no gap in chemical application between the first and further wiper elements as the apparatus moves over the ground.

14. A weed wiper apparatus including: i. a chassis including an attachment arrangement for attachment to a vehicle; ii. at least one wiper element mounted on or to the chassis, each wiper element including an absorbent material and a fluid outlet for supply of fluid to the absorbent material, the absorbent material being arranged to wipe fluid onto weeds as the apparatus moves over them; iii. a support arrangement configured to support the chassis above the ground, wherein the support arrangement includes one or more suspension elements.

15. An apparatus as claimed in claim 14 wherein the support arrangement includes a torsion bar suspension element.

16. An apparatus as claimed in claim 15 wherein the support arrangement is height adjustable.

17. An apparatus as claimed in claim 16 including an adjustment element configured to cause rotation of the torsion bar at a central point in order to adjust the chassis height.