The present invention relates to crop protection netting for use over growing plants, vines, bushes, or trees (herein: plants) in agricultural applications.
Crop protection netting may be used to cover crops while they are growing. One type of crop protection netting comprises a line knit construction with joining filaments as shown in
It is an object of the present invention to provide an improved or at least alternative crop protection netting.
In a first aspect the invention broadly comprises crop protection netting having a greater length than width and which is of a knitted mesh construction, knitted such that at yarn intersections in the netting multiple yarns of which the netting is formed are knitted around each other to define the netting mesh apertures so that the netting is stretchable in multiple directions, and wherein connecting yarn portions between said yarn intersections extend substantially linearly between intersections, and wherein:
In embodiments of the netting in which at least one of the multiple yarns of which the netting is formed comprises a tape, another or the other of the multiple yarns of which the netting is formed comprises monofilament ie the netting is knitted from monofilament and tape.
In embodiments of the netting which, in addition to the multiple yarns of which the netting is formed, also comprise multiple lay-in yarns or tapes, typically the lay-in yarns or tapes extend through the netting substantially in the same general direction to one another. Typically the lay-in yarns or tapes extend in a length of the netting (such as a warp or machine direction of the netting).
In some embodiments the lay-in yarns or tapes comprise tapes ie longitudinally extending single filament elements having four sides when viewed in cross-section, such as a rectangular or square cross-section.
In other embodiments the lay-in yarns or tapes comprise monofilament ie longitudinally extending elements having a circular or oval cross-section.
Preferably the netting is knitted from multiple yarns all extending along a length of the netting. In a preferred form each yarn follows an approximate zig-zag path along the length of the netting, looping at each intersection in the netting comprising the yarn, to a further netting yarn intersection one on one side and one on another side.
In another aspect the invention broadly comprises crop protection netting having a greater length than width and which is of a knitted mesh construction, knitted from multiple yarns extending along a length of the netting and following an approximate zig-zag path along the length of the netting, looping at each intersection in the netting comprising the yarn, to two further netting yarn intersections one on one side and one on another side, and wherein:
In embodiments of the netting in which at least one of the multiple yarns of which the netting is formed comprises a tape, another or the other of the multiple yarns of which the netting is formed comprises monofilament ie the netting is knitted from monofilament and tape. In preferred embodiments of this netting the tape may have a width in the range from about 1 to about 5 mm, or about 1 to about 3, or about 1 to about 2 mm, about 1.2 or about 1.4 to about 1.8 mm and in a particularly preferred form has a width about 1.6 or about 1.5 or about 1.4 or about 1.3 mm.
In embodiments of the netting which, in addition to the multiple yarns of which the netting is formed, also comprise multiple lay-in yarns which may be monofilament, multifilament, or tape, typically the lay-in yarns extend through the netting substantially in the same general direction to one another. Typically the lay-in yarns extend in a length of the netting (such as a warp or machine direction of the netting). In preferred embodiments the lay in yarn may have a diameter (or width if a tape) in the range from about 1 to about 5 mm, or about 1 to about 3 mm, about 1 to about 2 mm, or about 1.2 or about 1.4 to about 1.8 mm and in a particularly preferred form has a width about 1.6 or about 1.5 or about 1.4 or about 1.3 mm if tape or about 0.15 to 0.3 mm (and about 200 to 700 denier or about 500 to 700 denier) if monofilament.
In a preferred netting construction of the invention as will be further described with reference to the accompanying figures, each intersection is formed by knitting together of three yarn parts passing through the intersection:
In another preferred netting constructions of the invention as will be further described with reference to the accompanying figures, each intersection is formed by knitting together of three yarn parts passing through the intersection:
And each yarn intersection in the netting is connected to adjacent and surrounding yarn intersections by connecting yarn portions each comprising at least two yarn lengths. Preferably, each yarn intersection in the netting is connected to adjacent and surrounding yarn intersections by connecting yarn portions each comprising at least two yarn lengths that are at least free of knots or loops for about 1.5 mm or 2 mm or more in length between the intersections.
Preferably the netting comprises rows of said yarn intersections adjacent to one another in a first axis or direction across the netting, typically across a machine or manufacturing axis or direction of the netting. Preferably in immediately adjacent rows of yarn intersections in a second direction substantially orthogonal to said first direction, typically a machine or manufacturing axis or direction of the netting, the yarn intersections of the adjacent rows are staggered relative to one another.
Preferably the width of the netting is substantially uniform along the length of the netting.
Preferably the mesh size is in the range of approximately about 1, 2, or 3 mm to about 20 mm, 3 mm to 10 mm, more preferably approximately about 3 mm to 8 mm, even more preferably about 4 mm to 6 mm, even more preferably about 2 mm to 4 mm or 3 mm to 5 mm, even more preferably approximately about 3.5 mm to 4.5 mm, and most preferably approximately about 4 mm.
In one form each mesh aperture comprises four yarn sides between knitted yarn intersections. In a preferred form the lengths of the sides are substantially equal. The netting may alternatively be knitted so that the lengths of the mesh aperture sides are unequal or so that the mesh apertures have more than four sides in more complex mesh aperture shapes, for example but not limited to hexagonal shaped mesh apertures. In the four-sided mesh form of the netting the shape of the apertures may be substantially square, rectangular, triangular, or any other shape. The mesh aperture shape is referred to when the netting is equally and maximally taut but not stretched in both its length and width directions.
In one form the netting is formed from elastic yarn. In another form, the netting is formed from non-elastic yarn. In another form the yarn is formed from yarn that has some elongation when stretched but is neither elastic or non-elastic.
In a preferred form the netting is reflective. In another form the netting is non-reflective. In some embodiments the yarn forming the netting may be any of the following: black, white, transparent or translucent, white (UV or non-UV reflecting white) in colour, coloured, formed from a non-pigmented material, formed from plastic, or formed from a range of polymers. In some embodiments the yarn forming the netting may be heart reflective, in the infrared range.
In one form the netting is formed by twin, triple, or multiple or single monofilament fibre yarns. In one form the yarn is monofilament. Preferably, the monofilament has a substantially circular cross-section. More preferably the yarn has diameter in the range of approximately 0.1 mm to 1 mm, even more preferably about 0.2 mm to 0.8 mm, and even more preferably about 0.2 mm to 0.4 mm, and more preferably about 0.2 to 0.3 mm and most preferably about 0.15 mm to 0.25 mm In denier, the yarn is preferably in the range of approximately about 50 to 1000 denier, more preferably about 50 to 700 denier, even more preferably about 100 to 500 denier, even more preferably about 100 to 300 denier, even more preferably about 150 to 250 denier or even more preferably about 200 to 300 denier
Typically the netting is machine-knitted for example on a warp knitting machine or a weft insertion warp knitting machine.
Preferably the weight of the netting is in the range of about 10 to 100 grams per m2, more preferably about 15 to 80 grams per m2, even more preferably about 20 to 60 grams per m2, even more preferably about 20 to 40 grams per m2, or more preferably about 30 to 40 grams per m2 and even more preferably about 25 to 35 grams per m2.
In some embodiments the yarn may incorporate a compound or compounds added to cause or increase the extent to which the material reflects and/or absorbs radiation from the earth (terrestrial (long wave or infrared) radiation). Thus when the netting is placed over plants it will assist in retaining heat beneath the material, which may be desirable for some plants or applications.
In some embodiments the yarn may incorporate a compound or compounds added to cause or increase the extent to which the netting allows transmission and/or absorption of radiation from the earth (terrestrial (long wave or infrared) radiation). Thus when the netting is placed over or adjacent to plants it will assist in releasing the heat beneath the netting, which may be desirable for some plants or applications.
In other embodiments the yarn may incorporate a compound or compounds added to cause or increase the extent to which the netting reflects and/or absorbs solar radiation. Thus when the netting is placed over plants it will assist in cooling beneath the material, which may be desirable for some plants or applications.
In other embodiments the yarn may incorporate a compound or compounds added to cause or increase the extent to which the netting allows transmission and/or absorption of solar radiation. Thus when the material is placed over plants it will assist in increasing the heat beneath the material, which may be desirable for some plants or applications.
In a further aspect the invention broadly consists in a method of protecting plants comprising the step of at least partially covering a plant or row of plants with a crop protection netting of the first aspect of the invention.
In one form the step of covering the plant(s) comprises securing the netting over the entirety of the plant(s) and securing or fixing it to the ground surface surrounding the plants.
In another form the step of covering the plant(s) comprises suspending or supporting the netting over the top of the plant(s) as a canopy using a supporting structure or framework.
The term “yarn” as used in this specification, unless the context suggests otherwise is intended to mean multi or mono filament yarn, threads or fibres. The term “yarn” unless the context suggests otherwise, is intended to include longitudinally extending single filament elements having four sides when viewed in cross-section, such as a rectangular or square cross-section, also longitudinally extending elements having a multisided cross-section such as a triangular or hexagonal cross-section for example, and also longitudinally extending elements having a circular or oval or similar cross-section (sometimes referred to hereafter as monofilament). The yarns may be formed from any suitable polyolefin such as polyethylene or polypropylene, for example, or a mixture thereof, or an ethylene alpha-olefin, or a polyester, or a biopolymer, or a blend of any of the foregoing. Certain plastics are particularly useful when present as minor or major components. Ethylene vinyl acetate (EVA), ethylene butyl acrylate (EBA) and ethylene methyl acrylate (EMA) are useful for imparting elasticity and other properties. Polyesters and polystyrene, styrene-butadiene (SB), acrylonitrile-butadiene-styrene (ABS), styrene-acrylonitrile (SAN), polyethylene terephthalate (PET), polymethylmethacrylate (PMMA) and polycarbonate are useful as dye carriers and also for influencing radiation (reflecting, absorbing and transmission) properties and also other properties on the materials. Starch and other plant polymers are useful to increase biodegradability. Alternatively the yarns may comprise in part or whole of paper, wood or cellulose fibre, starch based polymers, casein, latex or in any combination of the above and/or with petroleum derived plastic polymers. The polymer or polymer blend may incorporate agents such as one or more pigments, UV stabilisers, or processing aids.
The phrase “mesh size” as used in this specification, unless the context suggests otherwise, is defined for the four-sided and equal-length sides form of mesh apertures as the length of the sides of the mesh aperture, or a substantially equivalent cross-sectional area for non-equi-length sided mesh apertures or other more complex mesh aperture shapes formed by more than four sides, the cross-sectional area being determined when the netting is taut but not stretched in both directions.
The term “reflective” as used in this specification is intended to mean that the netting filament or yarn themselves, excluding the air spaces, is reflective of at least about 20%, or about 30%, or about 40%, or about 50% or alternatively at least about 55% or alternatively at least about 60% or at least about 70% or at least about 80% of visible light on at least one side of the netting. In one embodiment of a reflective netting, the netting may reflect at least about 40% solar radiation on average across the UV (wavelength about 280-400 nm), visible (wavelength about 400-700 nm) and very near infrared (wavelength about 700-800 nm) ranges, and which transmits at least about 10% or about 5% on average of solar radiation across the wavelength range about 800-2500 nm. The netting may reflect more solar radiation than it transmits and absorbs in the UV, visible, and very near infrared ranges. The material may transmit at least about 15% or at least about 20% of solar radiation on average in the wavelength range about 800-2500 nm. Some or all yarn of a reflective netting may be formed from a resin comprising a white pigment, which resin has been formed by mixing a masterbatch consisting essentially of about 20 to 90% by weight of a white pigment or combination of pigments chosen from zirconium, strontium, barium, magnesium, zinc and calcium pigments, and a first polymer, with a second polymer such that the resin (masterbatch) comprising the white pigment comprises between about 5 to 50% by weight of the total mixture. In certain embodiments the white pigment may be selected from zirconium, dioxide, magnesium, zirconate, calcium zirconate, strontium zirconate, barium zirconate, zirconium silicate, zinc sulphide, calcium carbonate, barium sulphate, magnesium oxide, strontium carbonate, barium carbonate, potassium titanate and titanium dioxide.
The term “cover factor” means the percentage of the overall area of the netting material which comprises knitted, woven, or non-woven monofilament, yarn, or tape or a combination, forming the netting itself, judged from perpendicular to the plane of the netting when laid out flat, as opposed to air space in between the netting. Thus if a netting has a cover factor of 20% then the air space through the netting would be 80% of the total area of the netting.
The term “comprising” as used in this specification and claims means “consisting at least in part of”. When interpreting each statement in this specification and claims that includes the term “comprising”, features other than that or those prefaced by the term may also be present. Related terms such as “comprise” and “comprises” are to be interpreted in the same manner.
As used herein the term “and/or” means “and” or “or”, or both.
As used herein “(s)” following a noun means the plural and/or singular forms of the noun.
Preferred embodiments of the invention will be described by way of example only and with reference to the drawings, in which:
a is a plan view of a portion of the crop protection netting of
a-c each show the path of one of the three yarns in an individual intersection in the netting, and
a-c each show the path of a one of the three yarns in an individual intersection in the variation of the crop protection netting with extra looping, and
The crop protection netting of the invention is particularly suitable for covering trees or other plants for insect and bird exclusion. Particularly, the crop protection netting may be used over fruit trees including citrus trees to exclude insects that cause pollination in turn producing fruit with seeds. The netting is also stretchable or elongatable in both axes or directions, in the plane of the netting when laid flat, so that as trees or plants covered by the netting grow the netting can stretch to accommodate growth. The netting also does not comprise a relatively high level of knotting in the netting construction, which can add weight to the netting which weight may undesirably bear on often delicate foliage of covered plants. In particular the netting does not comprise lines of knotting formed by knotting the yarn upon itself along these lines, and also the netting yarn on all sides of the netting mesh apertures is not continuously knitted or knotted
Referring to
The netting is typically machine-knitted on a warp knitting machine or other knitting-machine. The netting comprises an array of mesh apertures 14. The mesh apertures 14 of the preferred embodiment are shaped as seen in
Referring particularly to
The netting is stretchable or extendible in both the width axis or direction indicated by arrow W and the length axis or direction indicated by arrow L in
In the preferred embodiment shown the mesh size of the equi-length four sided mesh apertures 14 is defined by the length of the sides 14a-d between the intersections 14e, measured when the netting is in a taut but non-stretched state in both length and width directions. Preferably the mesh size may be in the range of approximately 1, 2, or 3 mm to 20 mm, 3 mm to 10 mm, more preferably approximately 3 mm to 8 mm, even more preferably 4 mm to 6 mm, even more preferably 3 mm to 5 mm, even more preferably approximately 3.5 mm to 4.5 mm. In one preferred form the mesh size may be approximately 4 mm.
The yarn from which the netting described above is knitted is typically a monofilament yarn of any suitable material as previously mentioned. Typically, the yarn is extruded from a polymer resin. Each yarn yarns may be single monofilaments, or alternatively may comprise twin or multiple monofilaments. The monofilament yarns may be circular in cross-section or otherwise shaped. For circular monofilament yarns, the yarn preferably has a diameter in the range of approximately about 0.1 mm to 1 mm, even more preferably about 0.2 mm to 0.8 mm, and even more preferably about 0.2 mm to 0.4 mm, and more preferably about 0.15 to 0.3 mm and most preferably about 0.15 mm to 0.25 mm. In denier (grams per 9000 metres of the yarn) the yarn is preferably in the range of approximately about 50 to 1000 denier, more preferably about 50 to 700 denier, even more preferably about 100 to 500 denier, even more preferably about 100 to 300 denier, even more preferably about 150 to 250 denier or most preferably about 200 to 300 denier. The monofilament yarn may be stretchable or non-stretchable in length, and may be elastic or non-elastic depending on requirements. The netting is relatively lightweight. The weight of the netting is preferably in the range of approximately about 10 to 100 grams per m2, more preferably about 15 to 80 grams per m2, even more preferably about 20 to 60 grams per m2, even more preferably about 20 to 40 grams per m2, even more preferably about 30 to 40 grams per m2 and even more preferably about 25 to 35 grams per m2 and most more preferably about 30 to 40 grams per m2
The crop protection netting may have a cover factor (as herein defined) of less than about 30%, less than about 20%, less than about 10%, or less than about 5%.
Referring now particularly to
Referring now particularly to
The extra looping in
Another feature of the netting construction of the preferred embodiment is that each yarn intersection in the netting is connected to adjacent and surrounding yarn intersections by the connecting yarn portions 14a-d each comprising at least two yarn lengths. In a preferred embodiment, each yarn intersection in the netting is connected to adjacent and surrounding yarn intersections by connecting yarn portions each comprising at least two yarn lengths that are at least free of knots or loops for 2 mm or more in length between the intersections.
This intersection knitting is repeated at each intersection in the netting.
Netting of the invention may be formed from synthetic yarn (which as stated previously includes monofilament, multifilament, or tape) of a polymer containing pigments which give the material desired properties, such as desired light reflective, absorptive and/or transmission properties for example. In some embodiments, the yarn may be reflective as previously described, for example by using yarns having a white pigment. This reflection may provide various benefits to the trees or plants being covered, but may also enhance the visibility of the netting to insects such as pollination insects thereby increasing the deterrence effect of the netting to insects. For example crop protection netting of the invention may be knitted from yarn which reflects at least 10% or at least 50% of solar radiation on average across the UV (wavelength about 280-400 nm), visible (wavelength about 400-700 nm) and very near infrared (wavelength about 700-800 nm) ranges, and which transmits at least 10% on average of solar radiation across the wavelength range about 800-2500 nm. In some embodiments the yarn may reflect more solar radiation than it transmits and absorbs in the UV, visible, and very near infrared ranges. In some embodiments the yarn may transmit at least 15% or at least 20% of solar radiation on average in the wavelength range about 800-2500 nm. In some embodiments the yarn may reflect at least 10% on average of solar radiation across the wavelength range about 800-2500 nm. In some embodiments the yarn may absorb more solar radiation than it transmits and/or reflects absorbs in the UV range. In some embodiments the yarn may be knitted from yarn from a resin comprising at least 1% or at least 2% or at least 4% or at least 8% or at least 10% or at least 12% or at least 14% or at least 16% or at least 18% or at least 20% or at least 25% by weight of at least one white pigment. In some embodiments white pigment comprises a zirconium, strontium, barium, magnesium, zinc, calcium, titanium, or potassium pigment or a combination thereof, such as zirconium dioxide, magnesium zirconate, calcium zirconate, strontium zirconate, barium zirconate, zirconium silicate, zinc sulphide, calcium carbonate, barium sulphate, magnesium oxide, strontium carbonate, barium carbonate, titanium dioxide, potassium oxide, potassium titanate or a combination thereof. The white pigment may be present in the form of particles of size 0.02-5 microns or 0.1-3 microns or 0.2-2 microns or 0.3-1 microns.
This reflection may provide various benefits to the trees or plants being covered, but may also enhance the visibility of the netting to insects such as pollination insects thereby increasing the deterrence effect of the netting to insects. For example crop protection netting of the invention may be knitted from yarn which reflects at least 10% or at least 50% of solar radiation on average across the visible (wavelength about 400-700 nm) and very near infrared (wavelength about 700-800 nm) ranges, and which transmits at least 10% on average of solar radiation across the wavelength range about 800-2500 nm.
As stated the crop protection netting of the invention is particularly suitable covering trees or other plants for insect and bird exclusion. Particularly, the crop protection netting may be used over fruit trees including citrus trees to exclude insects that cause pollination in turn producing fruit with seeds. The netting is also stretchable so that as trees or plants covered by the netting grow the netting can stretch to accommodate growth. The netting also does not comprise a relatively high level of knotting in the netting construction, which can add weight to the netting which weight may undesirably bear on often delicate foliage of covered plants.
The foregoing description of the invention includes preferred forms thereof. Modifications may be made thereto without departing from the scope of the invention as defined in the accompanying claims.
Number | Date | Country | Kind |
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610079 | May 2013 | NZ | national |
Filing Document | Filing Date | Country | Kind |
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PCT/NZ2014/000079 | 5/1/2014 | WO | 00 |