WO2013006921A1

WO2013006921A1 - Weed pruner

Info

Publication number: WO2013006921A1
Application number: PCT/AU2012/000846
Authority: WO
Inventors: Gregory Butler
Original assignee: SOUTH AUSTRALIAN NO-TILL FARMERS ASSOCIATION Inc
Current assignee: SOUTH AUSTRALIAN NO-TILL FARMERS ASSOCIATION Inc
Priority date: 2011-07-13
Filing date: 2012-07-13
Publication date: 2013-01-17
Anticipated expiration: 2014-01-13

Abstract

A weed pruning method and apparatus, where one or more pruning heads are operable to prune, trim or slash, weeds or other plants, including between rows of commercial plants. The apparatus has at least one pruning head, provided with high-pressure water or cutting medium, where at least one UHP nozzle directs a water-jet to prune the weeds, or selected plants. Sensors detect the weeds, and operate the pruning head when a standing weed is detected.

Description

TITLE: WEED PRUNER

BACKGROUND OF THE INVENTION:

1. Field of the Invention:

[0001] This invention relates to a weed pruner.

[0002] The invention particularly relates, but is not limited to, a weed pruning method and apparatus (where the terms "weed" or "weeds" also include plants which have commercial value, which may require trimming or pruning periodically e.g. to promote plant growth).

2. Prior Art:

[0003] The control of weeds, to maximize crop growth, is a major problem in the agricultural and horticultural industries.

[0004] A major problem with existing weed control methods is that they usually cause collateral damage to the surrounding crops.

[0005] Herbicides can drift or diffuse and kill, or at least retard the growth, of the valuable crops; while mechanical methods can e.g. disturb or destroy the crop root structures.

[0006] Moreover, many weeds are developing resistance to herbicides; there are limited mechanical in-crop options; and labour for "hand-weeding" is generally cost prohibitive.

OBJECTS OF THE INVENTION:

[0007] It is an object of the present invention to overcome, or at least ameliorate, the problems with the prior art.

[0008] It is a preferred object to provide a non-herbicidal and non-mechanical alternative for weed control.

[0009] It is a further preferred object of the present invention to provide general, precision and inter-row weed control.

[0010] It is a still further preferred object to provide for weed control which can be combined with a weed-detection and/or identification system to ensure targeted weed control. This may include but, is not limited to, infrared plant recognition sensors. [0011] Other preferred objects will become apparent from the following description. SUMMARY OF THE PRESENT INVENTION:

[0012] In one aspect, the present invention resides in a method of pruning weeds, wherein:

a pruning head, having at least one high-pressure water-jet, is advanced past at least one weed to be pruned; and

the, or each, water-jet is directed to cut a selected portion of the weed or weeds.

[0013] Two or more pruning heads may be advanced along the same path, with each pruning head arranged to prune a selected weed, or type of weeds.

[0014] In a row-crop, respective pruning heads may be provided to prune the weeds between respective rows of the crop.

[0015] The pruning heads may be fixed to a support apparatus, or may be movably mounted thereon e.g. for rotation, oscillation, height and/or angular adjustment, or the like.

[0016] The motions may include single, double or multiple cutting heads working in synchrony or independently.

[0017] The motions include all known slashing and swathing patterns including, but not limited to, windscreen wiping motions, wave motions, pivot motions and oscillating motions.

[0018] The, or each, pruning head may have one or more water-jets; and the pruning heads can be adjustable by way of orifice size, cutting height and/or cutting angle to suit different specific pruning applications.

[0019] Additives, such as liquid polymers, can be added to the cutting media to increase the effective range of the pruning heads; while abrasives (and, optionally, trace elements) can be added to the liquid stream to increase the cutting action of the pruning heads.

[0020] In a second aspect, the present invention resides in an apparatus for pruning weeds, including:

a frame advance-able past at least one weed to be pruned;

at least one pruning head, as hereinbefore described, mountable on the frame; and

a source of high-pressure water (or other liquid cutting medium), optionally mountable on the frame, operably connectable to the, or each, pruning head.

[0021] The frame may be towed behind, or be mounted on, a prime-mover, such as a tractor, and may have one or more spray booms extendable therefrom; and the source of high-pressure water or cutting medium may include a water-storage tank, additive storage containers), high-pressure pump, and associated lines, valves and controls.

[0022] One or more sensors (e.g. thermal, IR) may be mounted on the frame to detect and/or identify specific weeds for selectively control of the pruning head(s).

[0023] The, or each, pruning head may be mounted on the frame via a mechanism which enables the pruning head to be oscillated, rotated, raised / lowered, tilted and/or otherwise have its' respective orientation to the adjacent weed(s) varied.

[0024] The pruning head(s) may achieve ground stabilization through mechanisms such as, but not limited to, a spring, guide-wheel, ski, parallelogram, or alternative ground hugging device.

BRIEF DESCRIPTION OF THE DRAWINGS:

[0025] To enable the invention to be fully understood, preferred embodiments will now be described with reference to the accompanying drawings, in which:

FIG. 1 is a schematic front elevational view of a first embodiment of a weed pruning apparatus where a pruning head is arranged to prune weeds inter- row between adjacent rows of crop plants (e.g. cereals);

FIG. 2 is a schematic front elevational view of a pruning head of a second embodiment of the apparatus;

FIG. 3 is a schematic front elevational view of a of a third embodiment of the pruning apparatus;

FIG. 4 is a schematic top plan view of a first operating motion for a single pruning head;

FIG. 5 is a schematic front elevational view of a second operating motion for the pruning head;

FIG. 6 is a schematic top plan view of a first operating motion for a pair of the pruning heads;

FIG. 7 is a similar view of a second operating motion for the pair of pruning heads;

FIG. 8 is a schematic isometric view of a pruning head having three water- jets;

FIG. 9 is a schematic front elevational view of a fourth embodiment of the pruning apparatus;

FIG. 10 is a schematic side elevational view of a modified form of the pruning apparatus of FIG. 9;

FIG. 11 is a schematic side elevational view of a fifth embodiment of the pruning apparatus;

FIG. 12 is a schematic side elevational view of a sixth embodiment of the pruning apparatus;

FIG. 13 is a schematic side elevational view of a seventh embodiment of the pruning apparatus; and

FIG. 14 is a schematic front elevational view of a pruning head, of an eighth embodiment, arranged for pruning, trimming, or slashing, in a horizontal plane.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:

[0026] In the preferred embodiments of the weed pruning apparatus of the present invention, weeds W to be pruned are located inter-row between adjacent rows of crop plants P e.g. cereals (such as wheat, barley or oats), corn stalks, cane stalks, cotton plants, vegetables or flowers, or the like. The weed pruning apparatus is operated so as to not cut, or otherwise disturb, the roots R of the plants P below the top surface of the soils S. [0027] The weed pruning apparatus 10, of the first embodiment illustrated in FIG. 1 , has a main frame 20 mounted on (e.g. by three-point linkage), or towed behind, a prime-mover (not shown)

[0028] A water-storage tank 21 , and optional storage containers for liquid polymer(s), abrasives and/or trace-elements (to be incorporated into the liquid cutting medium), are mounted on the main frame 20, the prime-mover, or on a separate e.g. towed tanker-vehicle.

[0029] A single pruning head 30 is provided to prune the weeds W in a given inter-row between the crop plants.

[0030] The pruning head 30 has single ultra-high pressure (UHP) nozzle 31 to produce a high-pressure water-jet 32, which is arranged to prune the weeds W above ground-level.

[0031] The UHP nozzle 31 in the pruning head 30 is preferably similar to, or of the type, used in ultra-high-pressure water-jet cutters sold by Flow International Corporation, of Kent, Washington, USA (www.flowporp.com / www.flowwaterjet.com).

[0032] The pruning head 30 is mounted on a support arm 22, in turn mounted on, and depending from, the main frame 20. The pruning head 30 is fixed to the support arm 22, which is pivotally mounted on the main frame 20; to enable the water-jet 32 to be swept across the weeds W as the pruning apparatus 10 advances the pruning head 30 between the row of plants.

[0033] A UHP pump 23 draws the water (or cutting medium) from the storage tank 21 and feeds the now highly-pressurized water (e.g. at 30+ bar / 500+ PSI) to a UHP line 24, which provides a manifold for the supply of the water to a plurality of the pruning heads 30.

[0034] Upper and lower UHP tube sections 25, 26 are interconnected by a flexible coil section 27, where the upper UHP tube section 25 is connected to the UHP line 24 and lower UHP tube section 26 is connected to the pruning head 30.

[0035] The flow of the high-pressure water (and any additive(s)) is controlled by a sensor 40 on the frame 20, which detects / identifies the weeds W, and controls a valve 28 upstream of the pruning head 30. (The sensor 40 may be e.g. of the IR-type, able to identify different weeds, to enable selective operation of the pruning head 30.)

[0036] The flexible coil section 27 enables the vertical position of the pruning head 30 relative to the main frame 20 to be selectively adjusted e.g. for different types of weeds W.

[0037] In the weed pruning apparatus 110 of the second embodiment, the support arm 122 is fixed to the main frame 120; and the pruning head 130 is pivotally mounted in a housing 129 at the lower end of the support arm 122. The pruning head 130 is arranged to have a transverse sweeping action as the pruning apparatus 100 is advanced.

[0038] FIG. 3 illustrates a weed pruning apparatus 210 of a third embodiment, where the pruning head 230 is rotatably mounted at the lower end of the support arm 222.

[0039] The UHP nozzle 231 may be located co-axially with the axis of rotation of the pruning head 230, or may be axially-offset therefrom, so that the water-jet 232 has the alternative paths as shown in solid- and dashed lines respectively.

[0040] The pruning head 230 may be rotated to cut the roots of the weeds W in a substantially-conical pattern below the top surface of the soil S.

[0041] The skilled addressee will appreciate that two or more pruning heads 30, 130, 230 may be provided per inter-row, with some / all of the pruning heads 30, 130, 230 being provided with liquid cutting media containing additives, such as liquid polymers, abrasives and /or trace elements to e.g. increase the range or cutting power of the pruning heads 30, 130, 230 to suit different weed types.

[0042] The skilled addressee will also appreciate that the pruning heads 30, 130, 230 may be mounted on the support arms 22, 122, 222 to enable the pruning heads 30, 130, 230 to be oscillated, rotated, raised / lowered, tilted, or have their orientation to the weeds W to be otherwise selectively changed . If preferred, the support arms 22, 122, 222 may be programmed e.g. to follow a robotic procedure. [0043] FIGS. 4 to 7 illustrate examples of a number of alternative operating patterns, or motions, for the pruning heads.

[0044] FIG. 4 illustrates a motion where a single pruning head 330 is oscillated about a substantially vertical axis; while FIG. 5 illustrates a motion where a single pruning head 430 is reciprocated along an axis transverse to the direction of advance of the weed pruning apparatus 410; their respective water-jets 332, 432 pruning the weeds W..

[0045] FIG. 6 illustrates a motion where a pair of pruning heads 530 are each pivotal about respective vertical axes, so that the respective water-jets 532 form a pattern similar to overlapping windscreen wipers.

[0056] FIG. 7 illustrates an alternative motion for the two pruning heads 630, which are mounted on a movable head 639, which in turn is mounted for reciprocating motion transverse to the direction of advance of the pruning apparatus, where the water-jets 632 cut across the weeds W.

[0057] The skilled addressee will appreciate that the orifice diameter of, and water-pressure supplied to, the UHP nozzles of the pruning heads can be selectively changed to suit the particular weeds to be pruned. Typically, the water-pressure will be 30 bar / 500 PSI, or greater.

[0058] As illustrated in FIG. 8, each pruning head 730 may have a plurality, e.g. three UHP nozzles 731 , producing three water-jets 732.

[0059] As indicated in FIG. 8, the pruning head 730 may be rotated about its central axis, e.g. in the direction of arrow A, where the axis of rotation AR is inclined to the vertical.

[0060] The weed pruning apparatus 810 of FIG. 9 shows the pruning head 830, with liquid jet 832, mounted adjacent the lower end of a support arm 822, provided with a ground-engaging wheel 850, rotatably journalled on an axle 851

[0061] The pruning head 830 is connected to the UHP output line 824 of UHP pump 823, the UHP pump 823 being connected to a storage tank 821 on a toolbar 820.

[0062] A controller 880, on the toolbar 820, has at least one LPS sensor 840, and operates to selectively open / close the pruning head 830 adjacent the weeds W, so that the water-jet 832 cuts the weeds just above the top surface of the soil S, without damaging the roots R of the plants P.

[0063] The weed pruning apparatus 910 of FIG. 10 is generally similar to the apparatus 810, except that the support arm 922 has an intermediate compression spring 922C interconnecting telescopic upper- and lower support arm sections 922A, 922B, to accommodate vertical movement of the ground-engaging wheel 950 as the apparatus is advanced.

[0064] The weed pruning apparatus 1010 of FIG. 11 has the pruning head 1030 mounted on a support arm 022 in the manner hereinbefore described, where the ground-engaging wheel 1050 has its axle 1051 mounted on a parallelogram-type suspension unit 1059 mounted on the toolbar 1020.

[0065] FIGS. 12 and 13 illustrate weed pruning apparatus 1110, 1210 of the sixth and seventh embodiments, where a ground-engaging stubble-skid, or ski, 1170, 1270 replaces the ground-engaging wheels 950, 1050 of the pruning apparatus 910, 1010 of FIGS. 10 and 11.

[0066] FIG. 14 illustrates an eighth embodiment, where the pruning head 1330 is arranged so that the water-jet 1332 cuts in a horizontal plane, to prune or "slash" weeds W, such as wild oats or radish, in cereal or lentil crops P, respectively.

[0067] As the pruning heads can be oriented at any angle between the vertical and horizontal, weeds W can be pruned within a range of crop-row widths, and any low or limp weeds will not readily escape pruning.

[0068] Due to the high velocity of the water jets , the pruning apparatus can be operated in windy conditions, with minimal, if any, spray drift.

[0069] The apparatus can be used during rainfall events; and on hot days when temperature inversions prevent conventional herbicide applications.

[0070] Plant stress, induced by heat or other aliments, will not impact on the pruning of the weeds, as the efficiency of the pruning of the weeds is independent of the health of the adjacent crop plants.

[0071] The pruning apparatus can be used year-round; and during both day and night (subject to the limitations of the targeting sensors 40).

[0072] In addition, different weeds can be targeted at different times during the growing cycle of the crop plants P. For example, germinating grass weeds in the inter-rows would be treated differently to summer melons in a fallow paddock.

[0073] Perennial weeds can be "slashed" to inhibit any canopy, and the root systems can also be pruned without significant soil disturbance, and the weed colony will not be spread over the paddock.

[0074] By selection of suitable sensors 40, pests such as snails can also be targeted.

[0075] As no chemical herbicides are used, the pruning method can be suitable for organic crop production; and the pruning system is also effective on herbicide-resistant weeds.

[0076] However, where organic farming is not an object, chemicals can be added to the water-jets.

[0077] Advantages of the pruning system, employing the method and apparatus hereinbefore described, include, but are not limited to:

1. The pruning system provides a weed management tool and prospective alternative to using herbicide or physical impact methods such as cultivation or mechanical blade slashing. It has the potential to be an effective tool in an Integrated Weed Management (IWM) strategy. 2. The functionality of the pruning system enables clean cutting or pulverising of weedy vegetation from any angle above the soil surface. These characteristics provide viable efficacy against a wide range of weeds, including immature and mature grass, broadleaf and woody weeds.

3. Unlike cultivation, the soil will not experience massive disruption that can result in detrimental outcomes such as erosion or secondary germinations of weeds. Moreover, the pruning apparatus is low draft because no steel or mechanical devices are being dragged through the soil or the foliage. Low draft has the potential to reduce fuel consumption, in addition to lessening the embodied energy required to manufacture the vehicle platforms, resulting in smaller engines, lighter frames and reduced costs.

4. Unlike mechanical blade slashing, the target weeds do not need to be of a certain height to be slashed and therefore weed control may be achieved before the weeds compete strongly with the crop.

5. Traditional blade slashers are limited because they operate parallel to the ground and only cut in the horizontal plane. Unfortunately, slashing only in the horizontal plane does not do a complete job because the blades do not get close enough to the ground. This problem is exacerbated in stony soils, where the proximity of mechanical blades is severely limited due to the high risk of mechanical wear and the risk of fire in late season and fallow situations.

This known limitation tends to favour all immature weeds, weeds with natural traits that result in them being short (Barley grass) or low-hanging (Brome grass) and weeds that have tendencies to sprawl (Wireweed). It is important to note that other established weed-seed control strategies that rely on blade slashing, such as hay cutting and harvesters fitted with chaff parts, also increase the weed-resistance pressure to horizontal slashing techniques.

6. Water-jet cutting from above the soil surface directed downwards at an angle somewhere between the horizontal and the vertical means that short, limp or sprawling vegetation cannot so readily escape the slashing process. 7. Moreover, there is limited risk of mechanical wear and virtually no-risk of fire irrespective of paddock or seasonal conditions.

[0078] Various changes and modifications may be made to the embodiments described and illustrated without departing from the present invention.

Claims

CLAIMS:

1. A method of pruning weeds, wherein:

2. A method as claimed in claim 1 , wherein:

two or more of the pruning heads are advanced along the same path, with each pruning head arranged to prune a selected weed, or type of weeds.

3. The method as claimed in claim 2, wherein:

in a row-crop, respective pruning heads are provided to prune the weeds between respective rows of crop plants.

4. A method as claimed in any one of claims 1 to 3, wherein:

the, or each, pruning head is fixed to a support apparatus, or is movably mounted thereon for rotation, oscillation, height and/or angle adjustment.

5. A method as claimed in any one of claims 1 to 4, wherein:

the, or each, pruning head has one or more water-jets; and the, or each, pruning head is adjustable by the pressure of water or cutting medium supplied to the pruning head or heads.

6. A method as claimed in any one of claims 1 to 5, wherein:

the, or each, pruning head is adjustable by way of orifice size, cutting height and/or cutting angle to suit different specific pruning applications.

7. A method as claimed in claim 1 , wherein:

additives, such as liquid polymers, are added to a cutting media from the water-jet or jets to increase the effective range of the pruning heads; and abrasives or trace elements are added to the cutting medium to increase the cutting action of the pruning heads.

8. An apparatus for pruning weeds, including:

a frame or tool-bar advance-able past at least one weed to be pruned;

at least one pruning head, having at least one high-pressure water-jet mountable on the frame; and

a source of high-pressure water, or other liquid cutting medium, operably connectable to the, or each, pruning head;

the, or each, water-jet pruning the weed or weeds as the apparatus passes the weed or weeds.

9. The apparatus as claimed in claim 8, wherein:

the frame is towed behind, or be mounted on, a prime-mover, and optionally has one or more spray booms extendable there-from; and

the source of high-pressure water or cutting medium optionally includes a water-storage tank, additive storage container(s), high-pressure pump, and associated lines, valves and controls.

10. The apparatus as claimed in claim 8 or claim 9, wherein:

one or more sensors, including thermal or IR sensors, are mounted on the frame to detect and/or identify specific weeds for selective control of the pruning head(s).

11. The apparatus as claimed in any one of claims 8 to 10, wherein: the, or each, pruning head is mounted on the frame via a mechanism which enables the pruning head to be oscillated, rotated, raised / lowered, tilted and/or otherwise have its' respective orientation to the adjacent weed or weed varied.

12. The apparatus of any one of claims 8 to 11 , wherein:

ground-engaging devices, including springs, wheels, skids, skis, or parallelogram suspensions, enable the height of the, or each, pruning head to be selectively adjusted.