CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 35 U.S.C. § 371 national phase application of PCT Application PCT/AU2018/050807, filed Aug. 2, 2018, which claims the benefit of priority of Australian provisional application No. 2017903063, filed Aug. 2, 2017, the entire contents of each of which are incorporated herein by reference in its entirety for all purposes.

FIELD OF THE INVENTION

This invention relates to methods for regulating the growth of plants, such as woody plants including trees and shrubs. More particularly, the invention relates, but is not limited, to methods of inserting a capsule containing an agent into a plant to regulate the growth of the plant. The invention also relates to capsules containing an agent for insertion into a plant to regulate the growth of the plant, and an apparatus for insertion of capsules into a plant.

BACKGROUND TO THE INVENTION

Exotic and endemic trees and shrubs can be problematic weeds under a variety of circumstances.

For example, under rangeland conditions weed trees and shrubs can form dense thickets that result in reduced stocking rates by displacing pasture, impede mustering, and restrict access to water. Where dense thickets are not produced it is likely that weed trees will shade and outcompete pasture grasses. These problems lead to reduced pasture productivity and accessibility. Weed trees and shrubs can also be problematic in waterways and wetlands, and in rights of way such as beside roads and railway lines, utility lines such as above ground power lines, and stock routes. Furthermore, introduced ‘amenity’ trees and shrubs can become weeds as they spread from gardens and parks into native forests. The weeds can impact the biodiversity and conservation value of the forest by outcompeting native plants and altering species assemblages.

Various strategies for herbicide-based control of weeds, including weed trees and shrubs, exist, which are described briefly as follows.

Foliar sprays for herbicidal weed control are applied either aerially, by tractor driven boom, or by smaller spot sprayer or splatter gun. The herbicide compound is often dissolved in a water miscible solvent, then diluted into a water solution with the possible addition of adjuvants to aid solubility, break down target surface tension, or improve adherence to the target.

The wick or wiper method involves rubbing a herbicide soaked wiper onto the target species. It has most utility in cropping systems were the weed is taller that the crop and can therefore be selectively treated.

Basal bark application is performed by spraying the base of target trees or shrubs, typically with a mixture of herbicide and diesel distillate to assist penetration through the bark. It is generally only recommended for use on plants less than 5 cm in diameter.

For larger woody weeds, the cut stump method, as the name suggests, is performed by felling the weed tree or shrub and painting or spraying the cut surface with a herbicide that is taken up and poisons the stump. Cut, scrape and paint is a variant of cut stump where an instrument (knife, chisel) is used to scrape off a section of bark remaining on the stump before herbicide treatment to ensure increased uptake of the herbicide.

Conventional stem injection methods also exist wherein herbicide is typically applied in either of two ways, ‘frill and fill’ or ‘drill and fill’. With frill and fill, an axe or chisel is used to cut into the stem (typically at an around 45° angle) to form a ‘frill’, before the herbicide is applied to the cut. In drill and fill a hole is drilled into the weed, that is then filled with herbicide.

Although suitable for weed control in many circumstances, the above described herbicide application methods are associated with various disadvantages. For example, the methods may require the handling of herbicide compositions in toxic forms; may be of limited effectiveness for certain weed types; may require monitoring of movement or transmission of applied herbicides from the site of application; may involve imprecise or excessive herbicide application; and/or may involve the use of relatively dangerous equipment. As such, new strategies for herbicidal control of weeds are desirable.

In a broad sense, strategies for herbicidal control of weeds will typically involve contacting a herbicide with the weed, to inhibit or restrain growth of the weed. It will be appreciated that desirable new strategies might also be developed involving contacting other agents with other plants, to exert other effects on such plants. For example, delivery of a suitable agent to a cultivated plant could enhance growth of or control disease in the cultivated plant. In at least some circumstances, it would be particularly desirable to develop new strategies that could be flexibly applied to herbicidal control of weeds, and to delivery of other agents to other plants.

SUMMARY OF THE INVENTION

The present invention is broadly directed to a method for regulating the growth of a plant, such as a woody plant, by inserting a container, such as a capsule, comprising an agent into the plant. The invention is also broadly directed to a container, such as a capsule, comprising an agent for insertion into a plant to regulate the growth of the plant. The invention is further broadly directed to an apparatus for insertion of a container, such as a capsule, into a plant.

In a first aspect, the invention provides a method of controlling the growth of a plant, the method including the steps of:

(a) inserting a capsule containing an agent into an opening formed in a plant; and

(b) closing the opening formed in the plant into which the capsule is inserted.

Suitably, the agent may be of a composition.

In certain preferred embodiments, the agent is a chemical agent.

In an embodiment, the plant according to this aspect is a weed.

In an embodiment, the plant according to this aspect is a cultivated plant.

Preferably, the plant according to this aspect is a woody plant, such as a tree, shrub, or liana.

In preferred embodiments, the opening in the plant is formed in a stem or branch of the plant. Preferably, the opening is formed in the stem of the plant.

Suitably, the opening is formed by penetration of the plant. Preferably, the opening is formed by drilling.

In particularly preferred embodiments, the opening formed in the plant has a diameter of between about 2 mm to about 30 mm; more preferably between about 4 mm to about 15 mm.

In particularly preferred embodiments, the opening formed in the plant has a depth of about 5 mm to about 50 mm; more preferably between about 10 mm to about 50 mm.

Preferably, an innermost end of the opening formed in the plant is located in sapwood of the plant.

In preferred embodiments of this aspect, the capsule inserted into the plant is located within sapwood of the plant.

Suitably, the capsule containing the agent according to this aspect is a soluble capsule. Preferably, the capsule is water-soluble. In preferred such embodiments, the capsule is formed from or comprises a material selected from the group consisting of water soluble alginate; polysaccharide; cellulose; polyethylene glycol, or derivatives thereof.

In preferred embodiments, the agent or composition comprising the agent contained by the capsule is in solid form. Suitably, the solid agent or composition may be in powder or granular form. Preferably, the solid agent or composition is dry or substantially dry.

In embodiments wherein the plant is a weed, preferably the agent is a chemical herbicide. In particularly preferred embodiments, the chemical herbicide is or includes an active agent selected from the group consisting of diuron, glyphosate, hexazinone, imazapyr, metsulfuron-methyl, picloram, tebuthiuron, or triclopyr. In certain preferred embodiments, the chemical herbicide is of a composition including two or more of said active agents.

In embodiments wherein the plant is a cultivated plant, preferably the agent is selected from the group consisting of a pesticide; a fertiliser; and a growth stimulant. Preferably, the agent is selected from the group consisting of a chemical pesticide; a chemical fertiliser; and a chemical growth stimulant.

Suitably, the opening formed in the weed is closed using an insoluble closure. Preferably, the closure is water-insoluble. In some embodiments the water-insoluble closure is formed from or comprises a material selected from the group consisting of metal; wood; cork; plastic; and natural or synthetic rubber. In some embodiments, the water-insoluble closure is an elastomer, inclusive of natural and synthetic elastomers. In one preferred embodiment, the water-insoluble closure is or comprises polypropylene.

In a second aspect, there is provided a capsule containing an agent for insertion into a plant to regulate the growth of the plant. Preferably the capsule is for use according to the method of the first aspect.

Preferably, the capsule is a soluble capsule. Preferably, the capsule is water-soluble. In preferred such embodiments, the capsule is formed from or comprises a material selected from the group consisting of water-soluble alginate; polysaccharide; cellulose; polyethylene glycol, or derivatives thereof.

Suitably, the agent contained by the capsule may be of a composition.

In preferred embodiments of this aspect, the agent or composition comprising the agent contained by the capsule is in solid form. Suitably, the agent or composition may be in powder or granular form. Preferably, the solid agent or composition is dry or substantially dry.

In an embodiment, the agent is a herbicide. In certain preferred embodiments, the herbicide is a chemical herbicide. In particularly preferred embodiments wherein the agent is a chemical herbicide, the chemical herbicide is or includes an active agent selected from the group consisting of diuron, glyphosate, hexazinone, imazapyr, metsulfuron-methyl, picloram, tebuthiuron, or triclopyr. In certain preferred embodiments, the chemical herbicide is of a composition including two or more of said active agents.

In an embodiment, the agent is selected from the group consisting of a pesticide; a fertiliser; and a growth stimulant. In certain preferred embodiments, the agent is selected from the group consisting of a chemical pesticide; a chemical fertiliser; and a chemical growth stimulant.

In a third aspect, there is provided a kit comprising a capsule of the second aspect, and a closure, wherein the closure is for closing an opening formed in a plant into which the capsule is inserted. Preferably the kit is for use according to the method of the first aspect.

Suitably, the closure is an insoluble closure. Preferably, the closure is water-insoluble. In some embodiments the water-insoluble closure is formed from or comprises a material selected from the group consisting of metal; wood; cork; plastic; or natural or synthetic rubber. In some embodiments, the water-insoluble closure is an elastomer, inclusive of natural and synthetic elastomers. In one preferred embodiment, the water-insoluble closure is or comprises polypropylene.

In a fourth aspect, there is provided an apparatus for insertion of a capsule into a plant, the apparatus comprising:

a housing for containing a capsule for insertion into a plant;

a channel member connected to the housing; and

an adjustable member capable of movement within the channel member,

wherein movement of the adjustable member within the channel member facilitates:

(i) penetration of a plant to form an opening in a plant; and

(ii) insertion of the capsule from the housing into the plant.

Preferably, the housing is movable relative to the channel member to position a capsule for insertion into a plant. Preferably, the housing is rotatable relative to the channel member to position a capsule for insertion into a plant.

Preferably, the housing is capable of holding a plurality of capsules for insertion into a plant. In preferred embodiments, the housing comprises a plurality of compartments for containing the respective plurality of capsules for insertion into a plant. Preferably, said compartments are discrete compartments.

In preferred embodiments, movement of the housing relative to the channel member to position a capsule for insertion into a plant includes aligning a compartment for containing a capsule with a channel of the channel member.

In preferred embodiments, the housing is connected to the channel member by a housing support. Preferably, the housing support facilitates rotation of the housing relative to the channel member.

Preferably, the housing of the apparatus is releasable from connection with the channel member to facilitate loading of a capsule into the housing. In preferred such embodiments wherein the housing is connected to the channel member by a housing support, the housing support facilitates release of the housing from connection with the channel member for loading a capsule into the housing.

Preferably, the housing support is pivotable relative to the channel member to facilitate connection and/or release of the housing with the channel member.

Preferably, the housing support is pivotable from an upright, closed position, to an inclined, open position to facilitate connection and release of the housing with the channel member.

Preferably, the adjustable member of the apparatus is slidable through a channel of the channel member to facilitate penetration of a plant to form an opening in the plant.

Preferably the adjustable member is slidable through a channel of the channel member to facilitate insertion of a capsule from the housing into the plant.

In certain preferred embodiments, sliding of the adjustable member through a channel of the channel member facilitates movement of the housing relative to the channel member to position a capsule for insertion from the housing into the plant.

In preferred embodiments, the adjustable member comprises or is engaged with a plant penetrating end. Preferably, the plant penetrating end is a drilling end. Preferably, the plant penetrating end is capable of passing through the housing and/or the housing support of the apparatus to penetrate a plant.

In preferred embodiments, the adjustable member comprises or is engaged with a capsule insertion end. Preferably, the capsule insertion end is capable of passing though the housing and/or the housing support of the apparatus to obtain a capsule from the housing and insert the capsule from the housing into a plant.

In preferred embodiments, the plant penetrating end of or engaged with the adjustable member is the capsule insertion end of or engaged with the adjustable member.

Preferably, the housing of the apparatus of this aspect is further suitable for containing a closure for closing an opening formed in the plant. In preferred embodiments wherein the housing comprises a plurality of compartments for containing a plurality of capsules for insertion into a plant, said compartments are further capable of containing respective closures.

In preferred embodiments wherein the housing of the apparatus is suitable for containing a closure for closing an opening formed in the plant, preferably, movement of the adjustable member within the channel member facilitates insertion of the closure into an opening formed in the plant to close said opening.

Preferably, the apparatus further comprises one or more plant-engaging protrusions for engagement with a plant. Preferably, the plant-engaging protrusion facilitates alignment of the channel member and/or the adjustable member to the plant, and/or stabilisation of the apparatus with respect to the plant. Preferably, the plant-engaging protrusion is of or connected to the housing and/or housing support of the apparatus. Preferably, the plant-engaging protrusion is in the form of one or more, more preferably a plurality, of pins or spikes.

In embodiments wherein a plant penetrating end of or attached to the adjustable member is capable of passing through the housing and/or housing support of the apparatus, preferably the one or more plant engaging protrusions are arranged around a position of the housing and/or housing support through which the plant penetrating end passes.

Preferably, the apparatus further comprises a handle. Preferably said handle facilitates adjustment of the adjustable member within the channel member. Preferably, said handle is of or connected to the channel member. In an embodiment, the handle may be of or connected to the adjustable member.

Preferably the apparatus of this aspect is engageable with an insertion actuator to facilitate penetration of a plant using the adjustable member. Suitably, the adjustable member is engageable with said insertion actuator. Preferably, said insertion actuator is a drill such as a power drill.

In embodiments, the apparatus of the fourth aspect is for use according to the method of the first aspect.

In preferred embodiments, the housing of the apparatus of the fourth aspect comprises the capsule of the second aspect, or the capsule and/or the closure of the kit of the third aspect.

A fifth aspect of the invention provides a system comprising the apparatus of the fourth aspect engaged with an insertion actuator to facilitate penetration of a plant using the adjustable member. Preferably said insertion actuator is a drill, such as a power drill.

It will be appreciated that the indefinite articles “a” and “an” are not to be read as singular indefinite articles or as otherwise excluding more than one or more than a single subject to which the indefinite article refers. For example, “a” capsule includes one capsule, one or more capsules or a plurality of capsules.

As used herein, unless the context requires otherwise, the words “comprise”, “comprises” and “comprising” will be understood to mean the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

