WO2014170630A1

WO2014170630A1 - Plant protector

Info

Publication number: WO2014170630A1
Application number: PCT/GB2014/050636
Authority: WO
Inventors: Barry SUTTON
Original assignee: Alba Trees Plc
Priority date: 2013-04-17
Filing date: 2014-03-04
Publication date: 2014-10-23
Also published as: EP2986103A1; GB201306958D0

Abstract

Disclosed is a protector for protecting an upper part of a sapling from pests. The protector has a generally conical barrier and a secondary barrier disposed around an axis, and an axial aperture extending though the protector. The conical and secondary barriers diverge with distance from the axis. When placed over and around an upper portion of a sapling, the protector provides a barrier to pests and may prevent or reduce the number of pests which are able to access the upper part of the sapling. A lower part of a sapling may be protected by protection means such as a net guard extending to, or through, the axial aperture of a protector disposed around the upper part.

Description

Plant Protector

Field of the Invention

The present invention relates to apparatus for providing protection to an upper part of a plant, and in particular to a sapling, from pests.

Background to the Invention

Plants, and in particular young plants, may be susceptible to damage caused by pests. In order to avoid damage during cultivation and in the early stages of growth of young plants after planting out, it is therefore known to protect plants from pests.

Insecticides and other chemicals are widely used, but can cause environmental damage. For example, the control of damage to young trees in woodland restocking, caused by Hylobius abietis (commonly known as pine weevils), has conventionally been controlled by environmentally hazardous chemical sprays, such as neonicotinoids which are known to be damaging to bee populations. Effective plant coverage can also be difficult to achieve and maintain throughout the early phases of growth during which the plant is most susceptible to pest damage, which can in some cases last for several years.

As an alternative to insecticidal or chemical treatments, it is known to provide young plants with a physical barrier to pest damage. Dipping or spraying techniques are known whereby a seedling or sampling is dipped into or sprayed with a hot wax or adhesive material which cannot be penetrated by pests. Such physical barriers may be effective in the short term, but it is necessary to leave at least a part of the plant exposed so that growth can occur.

Longer term protection may be provided by surrounding the root system and foliage portion of a plant with a net-guard having a mesh sized to prevent passage of pests above a predetermined size, as described in GB 2,411 ,388. However, the upper part of the net must remain open to permit plant growth and pests may gain access to the exposed upper part of the plant, particularly during periods of high pest populations.

Accordingly, it is an object of the present invention to avoid or minimize one or more of the foregoing disadvantages of known plant protection techniques. Summary of the Invention

According to a first aspect of the invention there is provided a protector for protecting an upper part of a sapling from pests;

the protector having a central axis and an axial aperture extending through the protector, sized to receive an upper part of a sapling in use of the protector; and a generally conical barrier disposed around the central axis, having an outer surface extending at an angle of between around 115 and 155 degrees to the central axis.

A secondary barrier may extend around the central axis, adjacent to the outer surface of the generally conical barrier, and may have a surface which opposes the outer surface of the generally conical barrier and which diverges therefrom, with distance from the central axis.

The protector may be placed over and around an upper portion of a sapling, with the central axis generally vertical and the outer surface facing upward. The outer surface is generally conical and lacks corners or vertices. By virtue of its angle and a lack of corners or vertices, the outer surface provides a barrier to pests with no or limited capability for flight), extending around the sapling and may prevent or reduce the number of pests which are able to access the upper part of the sapling.

The generally conical barrier and the outer surface thereof may be frustoconical or may deviate to some degree from a frustoconical shape. The outer surface may, for example, have an oval or ovoid cross section perpendicular to the central axis. The outer surface may be straight in a radial plane (i.e. a plane defined by the central axis and a radius extending from the central axis), or may have curvature in a radial plane.

The outer surface of the generally conical barrier may extend at an angle of between around 125 and 145 degrees, or between around 130 and 140 degrees, to the central axis. The outer surface may extend at an angle of around 135 or 140 degrees to the central axis.

The outer surface is preferably a low-grip surface. The properties of the outer surface may be selected so as to provide low-grip to a particular pest. The outer surface may, for example, be roughened so that the surface provides limited to grip to pests. The outer surface may have a surface roughness (R_a) in the range of around 0.2-1.0 microns, or more preferably between around 0.4 to 0.8 microns and may be around 0.7 microns. It has been found that certain pests, and in particular pine weevils, cannot grip surfaces which are slightly rough roughened (e.g. R_a « 0.7 microns) as well as they are able to grip very smooth surfaces (e.g. having a roughness lower than around 0.2 microns) or rough surfaces (e.g. having a roughness above around 1.0 microns).

The inventors have found that a slightly roughened surface of this nature affords less grip to a pine weevil than a perfectly smooth surface. This is postulated to result from the means by which pads on a weevil's legs grips a surface. The pads are made up from a multiplicity of microfilaments which are around 1-3 microns across at their tips. More grip is available to a pine weevil if more microfilaments are in contact with a surface. Slightly roughening a surface may reduce the number of microfilaments in contact with a surface, thereby reducing grip. If the surface is too rough, however, pine weevils are able to grip imperfections in the surface with claws at the tips of each leg.

Surface roughness is a measure of the texture of the surface and values of R_a calculated as the arithmetic mean of the absolute values of the vertical deviations of the roughness profile from a mean surface level. The outer surface may comprise a material having an inherently low coefficient of friction, for example by virtue of the material from which the generally conical barrier is formed or with which it is coated. The outer surface may be formed from a plastics material, such as polypropelyene. In some embodiments, the outer surface is smooth.

Some of the other surfaces, or all surfaces, of the protector may have the same or similar surface properties to the surface properties of the outer surface of the generally conical barrier. For example, the properties of the outer surface and/or the opposing surface of the secondary barrier may be selected so as to provide low-grip to a particular pest, as described above.

The length of the outer surface in a radial plane may be selected according to the size of pest. For example, a protector for protecting saplings from pine weevils may have an outer surface with a length of between around 1 ½ to 3 cm, or between around 2 to 2 ½ cm in a radial plane. The outer surface may have a length of between around 1 ½ to 2 ½ cm in a radial plane, or around 2 cm. Thus, an adult pine weevil cannot reach from the lower edge of the generally conical barrier (where grip may be available from the sapling itself or means for protecting a lower part of the sapling) to the upper edge of the generally conical barrier and is forced to attempt to traverse the outer surface of the generally conical barrier in order to climb further up the sapling.

The outer surface (and typically also the generally conical barrier) may extend to a maximum diameter of between around 4 and 10 cm, and may in some embodiments extend to a maximum diameter of around 5 cm.

The generally conical barrier may have an inner surface which is generally parallel to the outer surface.

The axial aperture may have a minimum diameter through the generally conical barrier (typically at an upper end of the barrier) of between around ½ and 2 cm, or between around 1 and 1 ½ cm. The axial aperture may have a minimum diameter through the generally conical barrier of between around 1 and 2 cm, or between around 1 ½ and 2cm.

The protector may comprise a stem gripping portion. The stem gripping portion may prevent the protector from moving when a sapling moves, for example in windy conditions.

The stem gripping portion may extend from an upper part of the protector.

The stem gripping portion may take the general form of a split cylinder or frustocone. The stem gripping portion may comprise a plurality of tines, which may be arranged around the central axis. The stem gripping portion may be castellated. The stem gripping portion may comprise resilient gripping members. Resilient gripping members may be deflected outward when the protector is disposed around a sapling, in use, and so positively engage with the sapling (for example a stem portion of a sapling) so that the protector is held in position. Resilient gripping members are also able to deflect outward so as to accommodate growth of a sapling.

The protector may comprise a tubular portion extending from the generally conical barrier. An outer wall of the tubular portion may extend from the outer surface of the generally conical barrier, and may be disposed at a steeper angle to the central axis than the outer surface.

The outer wall of the tubular portion may extend at an angle of between around 170 and 180 degrees, for example around 175 degrees, to the central axis. The outer wall of the tubular portion may be generally cylindrical, or may be generally frustoconical.

The tubular portion may be positioned between the generally conical barrier and stem gripping portion. The length of the outer wall of the tubular portion in a radial plane may be between around 3 mm and 7mm, or may be around 4mm or 5mm. The height of the tubular portion along the central axis may be between around 3 mm and 7mm, or may be around 4mm or 5mm. The outer wall of the tubular portion in a radial plane may be may be straight or may have curvature.

The protector may comprise a smooth or curved transition from the outer surface of the generally conical barrier to the outer wall of the tubular portion.

The properties of the outer surface of the tubular portion may be selected so as to provide low-grip to a particular pest, in the manner as described above. The protector may comprise a secondary barrier extending around the central axis, adjacent to the outer surface of the generally conical barrier, i.e. so as to be above the conical barrier in normal use. The secondary barrier may be positioned between the stem gripping portion and the generally conical barrier.

The secondary barrier may be generally flat. The secondary barrier may be in the form of a disc. The secondary barrier may extend at an angle of around 90 degrees to the central axis.

The secondary barrier may be generally conical.

The secondary barrier preferably has a lower surface (a surface opposing the outer surface of the generally conical barrier) which diverges from the outer surface of the generally conical barrier with distance from the central axis. Thus, the opposed faces of the generally conical barrier and the secondary barrier are furthest apart at their peripheries (for example between around 1 to 2 cm apart, or between around 1 ½ to 2 cm apart), where a pest is most likely to be able to find grip. This reduces the likelihood of a pest reaching between the peripheries of the two barriers and so urges pests to climb (or attempt to climb) the generally conical barrier.

The secondary barrier may extend to a maximum diameter of between around 4 and 10 cm, and may extend to a maximum diameter of around 5 cm. The generally conical barrier and the secondary barrier may extend the same diameter.

The generally conical barrier and the secondary barrier may be separated by the tubular portion. Advantageously, the height of the tubular portion or the length of its outer surface (in a radial plane) may be selected according to the size of the pest. For example, a protector for protecting saplings from pine weevils may have a tubular portion with an outer surface between around 2 mm and 6 mm, or around 4 mm, in length. Selection of the height of the tubular portion, or the length of its outer surface may also depend on the configuration of other parts of the protector, for example the slope of the generally conical barrier, or the diameters of the barriers.

The protector may comprise a smooth or curved transition from the opposed surfaces of the generally conical barrier and the secondary barrier, or between the outer wall of the tubular portion and the lower surface of the secondary barrier, as the case may be.

Protector may comprise one or more frangible portions. The protector may be frangible. Thus, the protector may be adapted to split so as to accommodate growth of the sapling and be shed by the sapling once it has grown large enough to withstand pest attacks.

The generally conical barrier, and/or the secondary barrier and/or the tubular portion may comprise frangible portions (and may be frangible) and may, for example, comprise lines or zones of weakness.

Lines or zones of weakness are preferably provided on the inner surface of the generally conical barrier, so that the outer surface remains free of features by which a pest might grip the protector and climb the generally conical barrier. Lines or zones of weakness are preferably provided on an upper surface of the secondary barrier, so that the lower surface remains free of features by which a pest might grip the protector. Similarly, lines or zones of weakness are preferably provided on an inner wall of the tubular portion, so that the outer wall remains free of features by which a pest might grip the protector.

Accordingly, an entire region defined by the outer surface and lower surface of the respective barriers and, in some embodiments, the outer wall the tubular portion, may be free of features such as edges or corners by which a pest might grip the protector. Lines of weakness, such as areas of reduced thickness material, may extend radially.

The protector may be of unitary construction, formed from a single piece of material.

The protector may be formed from two or more parts. The protector may comprise a first part, comprising a generally conical barrier, and a second part, comprising a secondary barrier.

The protector may comprise cooperating formations on the first and second parts, such as a lip around the first part against which the second part abuts, or a channel or depressions in which a ring or pegs of the second part are received. Such cooperating formations enable a positive engagement between the first and second parts, ensuring that the two barriers are correctly positioned in relation to one another. The protector may comprise or may be formed from a biodegradable material.

The invention extends in a second aspect to a plant protection system comprising a protector according to the first aspect and protection means for protecting at least a lower part of a sapling from pests.

The protection means may comprise a net-guard, sized to be placed around at least a lower part of a sapling and having a mesh sized to protect the sapling from pests. The net-guard may be tubular. The net-guard may be closed at one end, or open at both ends.

The next guard may have mesh apertures with a maximum dimension in the range from 1 to 10mm, preferably from 2 to 8mm, advantageously from 3 to 7mm. With a rhomboidal mesh aperture having a length of say 5mm, it will be appreciated that (with a resiliently expandable netting), whilst the width can increase up to around 5mm in the fully expanded condition of the tubular netting, in the unexpanded condition it can decrease to as little as 1 or 2mm.

Where resiliently expandable netting tubing is used, this helps ensure that the netting fits closely around the stem and foliage of the sapling as well as the root system portion.

Closely fitting, resiliently expandable netting, also facilitates disposition of the protector around an upper portion of the sapling, over or around the net-guard, so as to provide a continuous protection for the sapling between the protector and the protection means. It will be appreciated that various kinds of netting tubing may be used in accordance with the present invention. In general there is used a combination of material and net construction, which permits a large degree of resilient expansion of the tubing (with an accompanying expansion of the effective mesh aperture size of the netting). Typically there would be used netting tubing having a ratio of fully expanded diameter to unexpanded diameter of at least 1.1 :1 , preferably at least 1. 5: 1 conveniently from 1.1 : 1 to 3:1. Naturally, the diameter size range (unexpanded to expanded) of the netting tubing will be chosen so as to be appropriate to the sapling size. In general the diameter of the netting tube should be chosen so that the tube is only partly expanded to accommodate the sapling - generally so that it is expanded to not more than 70%, preferably not more than 50%, of its fully expanded diameter.

The protection means may comprise a wax or adhesive composition for coating at least a lower part of a sapling, for example by spraying or dipping.

The plant protection system may be provided in the form of a kit. The kit may further comprise a sapling. According to a third aspect of the invention, there is provided a protected sapling, the sapling having a protector according to the first aspect disposed around an upper part thereof.

Typically, a sapling comprises a stem portion or region and the protector is disposed around an upper part of the stem portion/region. An upper part of the stem portion/region may be engaged by a stem gripping portion of the protector.

A part of the sapling may extend through and above the protector. Active growing points of a sapling are typically located at the upper end of the sapling and may extend above the protector, in use, so that the protector does not hinder growth.

Approximately at least 10mm of the height of the sapling may extend above the protector. At least 50mm or, in some embodiments, at least 100mm of the height of the sapling may extend above the protector. It will be appreciated that as the sapling grows, a greater height may extend above the protector. The protected sapling may further comprise protection means on or around at least a lower part thereof. The protection means may comprise a net-guard. The protection means may comprise wax or adhesive composition, coating a lower part of the sapling.

The protection means may extend to meet the protector. At least a part of the protector may be positioned around a part of the sapling which is protected by (e.g. coated with or surrounded by) the protection means. For example, the next guard may extend to, and in some cases into or through, the axial aperture of the protector.

The protection means may extend to a part of the sapling which is below the level of the ground, when the sapling is planted. For example, the protected sapling may comprise a net-guard which encloses the root system of the sapling.

Thus, when planted in soil, the sapling may be provided with protection extending from the ground level to the protector around an upper part of the sapling, such that access to the above-ground foliage parts of sapling to pests is restricted or substantially prevented.

The protected sapling may comprise a plant protection system according to the second aspect. According to a fourth aspect of the invention there is provided a method of protecting a sapling from pests, comprising;

providing a protector having a central axis and an axial aperture extending through the protector, sized to receive an upper part of the sapling; and a conical barrier disposed around the central axis, having an outer conical surface extending from the central axis at an angle of between around 115 and 155 degrees;

and

disposing the protector around an upper part of the sapling with the outer conical surface of the protector facing away from a lower part of the sapling. A portion, for example one or more growing points, of the sapling may extend through the axial aperture and beyond the protector (i.e. so as to extend above the protector when the sapling is planted). Thus, the method may provide protection for growing points of the sapling from pests.

Preferred and optional features of the protector correspond to preferred and optional features of the first aspect.

The method may comprise introducing an upper part of a sapling through the axial aperture of the protector, so as to dispose the protector around the upper part of the sapling.

The method may comprise applying protection means to at least the lower portion of the sapling.

The protection means may comprise a net-guard. The method may comprise applying a net-guard around the sapling (so as to surround at least a lower portion of the sapling, optionally also the root system). The method may comprise disposing the protector around the upper part of the sapling and an upper part of the net-guard. A continuous physical protective barrier thus extends around the above-ground parts sapling (and in some cases also the root system), to the protector. A pest may be capable of climbing the net-guard, but cannot access the sapling within, and may be unable to progress past the protector. Thus, the likelihood of pests accessing the sapling through the upper part of the net-guard is reduced or substantially eliminated.

The method may comprise applying a net-guard around the sapling and subsequently disposing a protector around an upper part of the sapling.

The protection means may comprise a wax or adhesive composition and method may comprise spraying or dipping at least a lower part of the sapling therewith.

The method may comprise planting the sapling (in a growth medium such as soil). The method may comprise splitting the protector, for example under the action of a force applied by the growing sapling to the protector.

The term sapling applied herein includes but is not limited to a young tree, cultivated in a nursery or in the early stages of growth after planting out.

It will be understood that the terms "upper" and "lower" and similar terms relate to an orientation of a protector in use, installed around a sapling which has been planted.

Further preferred and optional features of each aspect of the invention correspond to preferred and optional features described in relation to any other aspect of the invention.

Description of the Drawings

An example embodiment of the invention will now be described with reference to the following drawings in which: Figure 1 shows a perspective view of a first embodiment of a protector.

Figure 2 shows the underside of the protector of Figure 1.

Figure 3 shows the upper surface of a secondary barrier for use with a protector.

Figure 4 shows a side view of the secondary barrier.

Figure 5 shows (a) a perspective view and (b) a side view of a second embodiment of a protector.

Figure 6 shows a surface profile of the outer surface of the conical barrier of the protector.

Figure 7 shows use of the protector to protect the upper part of a sapling.

Figure 8 shows use of a protection system to protect the upper and lower parts of a sapling.

Detailed Description of Example Embodiments

Figure 1 shows a protector 1 for protecting an upper part of a sapling from pests. An axial aperture 3, which is centred on a central axis A, extends through the protector and is sized to receive an upper part of a sapling. The protector has a generally conical barrier 5 disposed around the central axis, having an outer surface 7 extending at an angle of 135 degrees to the central axis. It will be appreciated that the outer surface can, in alternative embodiments, extend at another angle.

The protector is for use in protecting an upper part of a sapling from pine weevils. It has been found that the angle of 45 degrees to the horizontal (i.e. 135 degrees to the central axis) is sufficient to hinder the ability of most pine weevils to grip the outer surface 7. The protector is moulded from a plastics material, in the case of protector 1 , polypropylene. Surfaces formed from this material have an inherently low coefficient of friction.

The diameter of the conical barrier 5 at its widest part (the lower end) is around 5 cm. This ensures that the shortest path along the outer surface 7, which is in a line along a radial plane, exceeds the maximum reach of an adult pine weevil and means that a pine weevil must try to walk on the low-grip outer surface 7 in order to climb past the protector, in use.

The protector 1 has a stem-gripping portion 9 extending from the upper part of the protector. The stem-gripping portion has tines 1 1 in a generally frustoconical arrangement, which extend slightly toward the central axis A. This can best be seen in the view from the underside of the protector, in Figure 2. The tines are resilient and so are adapted to flex outwardly when the protector is disposed around the upper part of a sapling, thus gripping the sapling and holding the protector in position.

Between the conical barrier 5 and the stem-gripping portion 9 is a tubular portion 13. The outer wall 15 of the tubular portion extends at an angle of around 175 degrees to the central axis A, which is much steeper than the outer surface 7.

The protector 1 also optionally includes a lip 17 around the upper end of the tubular portion, and alternate tines 11 are provided with ramps 19. The lip and ramps function to retain a secondary barrier in a correct position, as described below with reference to Figures 3-5.

The protector 1 has a frangible portion. As can be seen in Figure 2, the inner surface 8 of the conical barrier 5 has lines of weakness 20 in the form of channels, which reduce the thickness of the material of the conical barrier. The channels extend radially from the central axis. Thus, the protector is adapted to preferentially split or tear along the lines of weakness 20, which allows a sapling to grow and shed the protector when it is no longer required. Provision of the lines of weakness on the inner surface of the conical barrier ensures that the outer surface remains free of features which might offer grip to a pest.

The lines of weakness 20 continue along the inner wall 12 of the tubular portion 13.

Figure 3 shows a disc-shaped secondary barrier 23 having a central aperture 22. The secondary barrier 23 is also frangible, and is provided with radial lines of weakness 25, extending along the upper surface 24 of the secondary barrier. As can be seen in the side view of Figure 4, the lines of weakness 25 are in the form of v-shaped channels which reduce the thickness of the material of the secondary barrier along the lines of weakness 25. The lower surface 26 of the secondary barrier is flat.

The central aperture 22 of the secondary barrier 21 is sized to fit over the neck gripping portion 9 of the protector 1 , but is slightly smaller in diameter than the lip 17 around the upper end of the tubular portion 13. The secondary barrier can therefore be introduced over the neck-gripping portion and forced over the ramps 19, causing the tines 11 to be deflected slightly inward, until the secondary barrier passes the lower ends of the ramps, the tines spring back out and the secondary barrier clicks into place between the ends of the ramps 19 and the lip 17.

The protector 1 and the secondary barrier 21 can be assembled in this way so as to form a protector 30, which is shown in Figure 5.

The tubular portion 13 provides a gap of around 4.5 mm between the top of the conical barrier 5 and the secondary barrier 21. This ensures an adequate gap of, in the embodiment shown, around 1.7 cm between the outer edges of the barriers 5, 21 (which exceeds the maximum reach of an adult pine weevil). A pine weevil has an exo- skeleton which makes it difficult for it to manoeuvre in confined spaces such as the gap provided between the barriers thereby making it almost impossible for it to gain access to the lower surface 26 of the secondary barrier. The few pine weevils that gain access to the outer surface 7 of the conical barrier must therefore reach directly up to the secondary barrier and thereby lose grip.

Too great a gap between the barriers would require use of excess material, increasing costs, and the protector would in use be disposed around an unnecessarily large part of a sapling. Too small a gap may require the protector to have a greater diameter in order to ensure adequate distance between the peripheries of the barriers. This would again require excess material, or require the lower surface of the secondary barrier to be angled upwards, which may at least to some degree reduce its effectiveness.

Provision of the lines of weakness 20, 25 on respectively the lower, inner face 8 of the conical barrier 5, the inner wall 12 of the tubular portion 13 and the upper face 24 of the secondary barrier 21 , ensures that the region generally indicated as B, between the barriers, is free of corners and edges which could afford grip to a pest, such as a pine weevil.

The protector 30 may alternatively be formed (e.g. by injection moulding) from a single piece of material. The surfaces of the protectors 1 , 30 (including in particular the outer surface 7, the outer wall 13 and the lower surface 26) have a surface roughness R_a of around 0.7 microns. Figure 6 shows a plot of the surface profile of the outer surface 7 of the protector 1. The distance 32 between gridlines in the vertical axis denotes 2 microns. The distance 34 between gridlines in the horizontal axis denotes 10 microns.

As detailed above, the protectors 1 , 30 are specifically adapted to protect the upper part of saplings from pine weevils (by virtue of its dimensions, the angle and surface roughness, the material from which the protector is formed and so forth). It will be appreciated that the dimensions and configuration of alternative embodiments may differ according to their intended use.

As shown in schematically in Figure 7, the protector of the present invention, is used to provide protection for the upper part of a pine sapling 40. The sapling 40 has a root system 42 (underground when the sapling is planted out), a stem portion 44 and foliage 46. The most active growing points of a sapling are typically at an upper portion 48 of the sapling. The upper part 48 can be protected from pine weevils by disposing the protector 30 (or 1) around the stem 44, as shown in Figure 7(b), by introducing the upper part of the sapling through the central aperture 3 of the protector. Means may also be provided for protecting the lower part 49 of the sapling.

The sapling 40 may, for example, be protected with a net-guard 50, applied as described in GB241 1388 (Figure 8(a)). A protector 30 may then be disposed around an upper part of the sapling 40 (Figure 8(b)) with an upper part of the net-guard 50 and the upper part of the sapling extending through the central aperture 3 of the protector. The sapling is thus provided with continuous protection system extending from the root system 42 up to the protector 30, which protects the sapling against pests.

As the sapling grows, typically over a period of 2-4 years after planting out, the net- guard expands and the upper branches 48 grow out of the open top of the net-guard. Eventually, both the net-guard and the protector split and come away from the young tree, once it has grown to a size sufficient to be able to withstand weevil attack.

Claims

1. A protector for protecting an upper part of a sapling from pests;

the protector having a central axis and an axial aperture extending through the protector, sized to receive an upper part of a sapling in use of the protector; and a generally conical barrier disposed around the central axis, having an outer surface extending at an angle of between around 115 and 155 degrees to the central axis; and

a secondary barrier extending around the central axis, adjacent to the outer surface of the generally conical barrier, and having a surface which opposes the outer surface of the generally conical barrier and which diverges therefrom, with distance from the central axis.

2. A protector according to claim 1 , wherein the secondary barrier extends at an angle of around 90 degrees to the central axis.

3. A protector according to claim 1 or claim 2, wherein the outer surface of the generally conical barrier and/or the opposing surface of the secondary barrier is a low-grip surface.

4. A protector according to any preceding claim, wherein the outer surface of the generally conical barrier and/or the opposing surface of the secondary barrier has a surface roughness (R_a) in the range of around 0.2-1.0 microns.

5. A protector according to any preceding claim, wherein the outer surface of the generally conical barrier and/or the opposing surface of the secondary barrier, comprises a plastics material having an inherently low coefficient of friction.

6. A protector according to any preceding claim wherein the length of the outer surface in a radial plane is between around 1 ½ to 3 cm.

7. A protector according to any preceding claim, comprising a stem gripping portion extending from an upper part of the protector.

8. A protector according to claim 7, wherein the stem gripping portion comprises resilient gripping members.

9. A protector according to any preceding claim, wherein the generally conical barrier and the secondary barrier are separated by a tubular portion extending from the generally conical barrier, an outer wall of the tubular portion extending from the outer surface of the generally conical barrier and disposed at a steeper angle to the central axis than the outer surface of the generally conical barrier.

10. A protector according to claim 9, wherein the length of the outer wall of the tubular portion in a radial plane is between around 3 mm and 7 mm.

1 1. A protector according to any preceding claim, comprising one or more frangible portions.

12. A protector according to claim 1 1 , wherein lines or zones of weakness are provided on an inner surface of the generally conical barrier, and/or an upper surface of the secondary barrier, and/or an inner wall of the tubular portion.

13. A plant protection system comprising a protector according any preceding claim, and protection means for protecting at least a lower part of a sapling from pests.

14. A plant protection system according to claim 13, wherein the protection means comprises a net-guard, sized to be placed around at least a lower part of a sapling and having a mesh sized to protect the sapling from pests.

15. A protected sapling having a protector according to any one of claims 1 to 14 disposed around an upper part thereof.

16. A protected sapling according to claim 15, comprising protection means on or around at least a lower part thereof.

17. A protected sapling according to claim 16, wherein the protection means comprises a net-guard around at least a lower part of the sapling. A protected sapling according to claim 17, wherein the next guard extends to, into, or through, the axial aperture of the protector.

A method of protecting a sapling from pests, comprising;

providing a protector according to any one of claims 1 to 12;

and

disposing the protector around an upper part of the sapling with the outer conical surface of the protector facing away from a lower part of the sapling.

A method according to claim 19, comprising applying a net-guard around the sapling, so as to surround at least a lower portion of the sapling, and disposing the protector around the upper part of the sapling and an upper part of the net- guard.