Substrate dispensing tool

Abstract

An apparatus for dispensing a substrate onto a crop includes a reservoir 12 with a loading aperture defined in its base. A loading chamber 14is arranged below, and in communication with, the loading aperture 14a. The loading chamber includes a loading port (15c, figure 3) at its base. A conveyor (16) is arranged to collect substrate falling through the loading port and transport it to a dispensing point (16c, figure 8) where the substrate is dispensed onto a crop. The apparatus may comprise a speed sensor for detecting the speed of the conveyor and a control unit configured to determine a substrate distribution rate using the speed of the conveyor and a substrate distribution value representative of an amount of substrate carried by the conveyor. A mobile platform comprising the apparatus mounted on a body of the mobile platform is also disclosed.

Description

The present invention relates to an apparatus for dispensing a substrate onto a crop. The treatment of agricultural crops can be an effective way of increasing the yield of the crop, maintaining the health of the crop or the health of the soil, preventing weed growth, or improving the quality of the harvested produce. The process of crop treatment involves dispensing a substrate, containing beneficial chemicals, nutrients, particulates, or organisms, onto the crop. Substrate may be dispensed onto the soil before or after the crop has been planted, but commonly substrate is dispensed onto the canopy of an established crop. Treatment may be performed on an entire crop, or only a region of a crop. In either case, however, it can be beneficial to ensure that the amount of substrate dispensed per unit area of crop (i.e. the dose) is as uniform as possible across the entire treated area. Crop treatment may be carried out by hand, but this often results in crops receiving inconsistent amounts of substrate, owing to the dose being subjective to the labourer performing the operation. The automation of crop treatment methods has gone some way to addressing this need, but conventional crop treatment devices provide crude substrate dispensing mechanisms that are insensitive to the delicacy of some substrates. For example, the effectiveness of substrates containing predatory mites for the treatment of pests such as spider mites or thrips can be significantly reduced if the substrate is subjected to shearing or impact forces. These forces can damage the predatory mites and limit their mobility, thereby reducing the ability of the mites to feed on pests present within the crop. Conventional devices that are intended to dispense substrate efficiently and substantially uniformly often do so at the expense of appropriate handling of the substrate. This can result in the substrate becoming damaged, which can reduce its efficacy. The present invention seeks to provide an apparatus for dispensing a substrate onto a crop that addresses the above problems. When viewed from a first aspect, the invention provides an apparatus for dispensing a substrate onto a crop, the apparatus comprising: a reservoir for holding a substrate, the reservoir comprising a loading aperture defined at a base of the reservoir; a loading chamber arranged below the loading aperture and in communication with the reservoir via the loading aperture, the loading chamber comprising a loading port at a base of the loading chamber; and a conveyor comprising a collection point and a dispensing point, wherein the collection point is arranged below the loading port so as to collect substrate falling through the loading port, and wherein the conveyor is arranged to transport the collected substrate to the dispensing point of the conveyor, where the substrate is dispensed onto a crop. The present invention provides an apparatus comprising a reservoir, arranged to store substrate that is to be dispensed onto a crop. The reservoir comprises a loading aperture at its base, through which substrate stored in the reservoir can fall, under the action of gravity. The apparatus further comprises a loading chamber, arranged to receive substrate falling through the loading aperture under the action of gravity. The loading chamber comprises a loading port, defined in the base of the loading chamber. A conveyor is arranged below the loading port to collect substrate falling through the loading port at a collection point of the conveyor, and to transport the collected substrate to a dispensing point of the conveyor. The substrate is dispensed from the dispensing point onto the crop. It will be appreciated that, by arranging the conveyor below the loading port so as to collect substrate falling through the port, the falling substrate is decoupled from the weight of the substrate remaining in the reservoir and the loading chamber. This may beneficially reduce the shear forces exerted on the substrate as it is collected by the conveyor, thereby helping to reduce the likelihood of the substrate (e.g. predatory mites) being damaged. Furthermore, providing a loading chamber that is in communication with the reservoir via an aperture means that the loading chamber may act as a buffer to further aid the decoupling of the collected substrate from the substrate remaining in the reservoir. Preferably the loading chamber is in direct communication with the reservoir via the loading aperture, i.e. preferably there is no intermediate volume between the reservoir and the loading chamber. Preferably the loading aperture is defined in a wall that is common to both the reservoir and the loading chamber. The substrate may comprise any of: vermiculate, sawdust, fertiliser pellets, and granulated ammonium nitrate. Preferably the substrate comprises predatory mites. The apparatus is preferably arranged to be mounted on a mobile platform. The mobile platform is preferably configured to travel along a row of crops. Mounting the apparatus on a mobile platform in this way may improve the ease with which substrate is dispensed onto a crop, e.g. by reducing the manual labour required, and may also help to improve the consistency of the dispensed dose, e.g. by balancing the dispensing speed of the apparatus with the speed of the mobile platform along the row of crops. Thus, when viewed from a further aspect, the invention provides a mobile platform comprising a body and an apparatus for dispensing a substrate onto a crop, wherein the apparatus is mounted on the body and wherein the apparatus comprises: a reservoir for holding a substrate, the reservoir comprising a loading aperture defined in a base of the reservoir; a loading chamber arranged below the loading aperture and in communication with the reservoir via the loading aperture, the loading chamber comprising a loading port in a base of the loading chamber; and a conveyor comprising a collection point and a dispensing point, wherein the collection point is arranged below the loading port so as to collect substrate falling through the loading port, and wherein the conveyor is arranged to transport the collected substrate to the dispensing point of the conveyor, where the substrate is dispensed onto a crop. The mobile platform preferably comprises robotic crop treatment device. Preferably the apparatus is arranged to be detachably mounted on the body of the mobile platform. The mobile platform preferably further comprises a motor for moving the mobile platform along a row of crops to be treated. Preferably the mobile platform comprises one or more wheels. The motor is preferably arranged to actuate the one or more wheels to move the mobile platform. The mobile platform preferably comprises one or more sensors configured to collect data relating to the operation of the mobile platform. The one or more sensors are preferably configured to determine one or more of the speed, the direction of travel, and / or the location of the mobile platform. The mobile platform may comprise a positioning module for determining the location of the mobile platform. The positioning module may comprise a Global Navigation Satellite System (GNSS) module (e.g. a Global Positioning System (GPS) module). The mobile platform preferably comprises a control unit for controlling the operation of the mobile platform. The control unit is preferably configured to control the operation of the motor (e.g. and thus the one or more wheels). The control unit is preferably configured to use data collected by the one or more sensors in order to control the operation of the mobile platform. In some embodiments, the mobile platform comprises a transceiver (e.g. a radio transceiver) for communicating with a remote monitoring centre. The remote monitoring centre may comprise a processor for processing data received from the mobile platform and, optionally, from one or more other mobile platforms in communication with the remote monitoring centre. The transceiver is preferably configured to receive data and / or control signals from the remote monitoring centre. Thus, the remote monitoring centre may act as a supervisor that monitors the performance of the mobile platform, and optionally one or more further mobile platforms, e.g. operating within a field, and may control each mobile platform so as to enable crops within the field to be treated efficiently. The body of the mobile platform may comprise a substantially arched shape. Preferably the body comprises a pair of parallel walls defining an open channel therebetween. This arrangement is particularly suited to treating crops that have been planted in discrete rows, e.g. in planters. The channel is preferably arranged to receive the plants to be treated as the mobile platform moves along the row. Preferably the one or more wheels are mounted on a lower surface of one or both of the pair of parallel walls. Preferably the body comprises an arch extending from an upper surface of a first of the parallel walls to an upper surface of a second of the parallel walls. The arch preferably comprises a crest at the highest point of the arch. The crest is preferably equidistant between the pair of parallel walls. Preferably the apparatus is mounted on the body such that the dispensing point of the conveyor is adjacent to the crest of the arch. This helps the substrate to be dispensed evenly onto the crop below. The apparatus preferably comprises a concave (e.g. curved) shape. Preferably the apparatus is mounted on the body such that the apparatus extends downwardly from the crest of the arch of the body. Preferably the apparatus is curved such that the apparatus follows the curve of the arch of the body of the mobile platform, e.g. from the crest towards an upper surface of a wall of the pair of parallel walls. Preferably the apparatus does not protrude into the channel defined between the walls of the body. This arrangement helps to reduce the profile of the mobile platform, which may reduce the risk of crops becoming damaged as the mobile platform In some embodiments, the mobile platform further comprises an ultraviolet (UV) treatment tool for treating crops with UV light. This may help to reduce the spread of diseases such as powdery mildew. The UV treatment tool may be mounted to the body of the mobile platform. Preferably the UV treatment tool is mounted on a wall of the body of the mobile platform so as to direct UV light onto the crops to be treated. Preferably the UV treatment tool is mounted on one of the pair of parallel walls so as to direct UV light into the channel defined between the walls. Preferably, the apparatus is mounted on the body of the mobile platform such that it is offset from the UV treatment tool in the direction of travel of the mobile platform. In other words, the apparatus is preferably mounted such that it is either forwards or rearwards of the UV treatment tool, depending on the direction in which the mobile platform is traveling, i.e. rather than at the same location as the UV treatment tool. Preferably the mobile platform is configured to move along a row of crops to be treated such that the apparatus is rearwards of the UV treatment tool. Preferably the UV treatment tool is mounted on a leading side of the mobile platform and the apparatus is mounted on a trailing side of the apparatus. This may help to avoid substrate that has been dispensed onto the crop being exposed to UV light by the UV treatment tool, which may damage the substrate (e.g. predatory mites). In some embodiments, the mobile platform comprises a first substrate-dispensing apparatus in accordance with the present invention on a leading side of the mobile platform, and a second substrate-dispensing apparatus in accordance with the present invention on a trailing side of the mobile platform. The mobile platform may comprise a UV treatment tool arranged between the first and the second substrate dispensing apparatuses. This arrangement may allow the mobile platform to be operated bi-directionally, i.e. without requiring the mobile platform to rotate 180° when reversing its direction, which may improve the speed and efficiency of crop treatment. In some embodiments, the mobile platform comprises a forced gas flow device for directing a flow of gas onto the (e.g. canopy of the) crop. The device is preferably a forced air flow device arranged to direct a flow of air onto the crop. This may help to treat the crop by removing pests and / or diseased plant matter from the crop, thereby performing a ‘first pass’ treatment that may improve the effectiveness of the substrate dispensed by the apparatus. Preferably the apparatus is mounted on the body of the mobile platform such that it is offset from the forced gas flow device in the direction of travel of the mobile platform. Preferably the mobile platform is configured to move along a row of crops to be treated such that the apparatus is rearwards of the forced gas flow device. This may help to avoid the forced gas flow device blowing dispensed substrate off the crop. The conveyor may comprise a blower configured to direct a stream of gas (e.g. air) from the collection point to the dispensing point. The conveyor may comprise a tunnel through which the stream of gas is directed. In such embodiments, substrate falling through the loading port is carried by the stream of gas towards the dispensing point. In preferred embodiments, the conveyor comprises a conveyor belt arrangement. The conveyor belt arrangement preferably comprises one or more pulleys and a conveyor belt. The conveyor belt is preferably arranged to extend over the one or more pulleys and to move as the one or more pulleys rotate. The conveyor belt may comprise a continuous band of material, e.g. rubber. The conveyor belt is preferably arranged to move along a closed-loop path. Preferably the conveyor comprises a motor. The motor is preferably an electric motor, e.g. a stepper or a brushless / brushed motor. The motor is preferably arranged to actuate the conveyor belt so as to cause the conveyor belt to move at least from the collection point to the dispensing point. The motor may be arranged to actuate a pulley of the conveyor belt arrangement in order to cause the conveyor belt to move. The conveyor may comprise a belt tensioner for applying a tensioning force to the conveyor belt. The belt tensioner may comprise a free-spinning pulley. The conveyor belt preferably defines one or more grooves for holding the substrate. The conveyor belt may comprise a lower surface, arranged in contact with one or more of the pulley(s), and an upper surface, for collecting the substrate falling through the loading port. Preferably the grooves are defined in the upper surface of the conveyor belt. The conveyor belt preferably defines a plurality of grooves spaced at regular intervals along the length of the conveyor belt (where the length is the dimension of the conveyor belt extending in the direction of travel of the conveyor belt). The plurality of grooves are preferably of equal volume, i.e. each groove is arranged to hold the same volume of substrate. By providing a plurality of regularly spaced grooves and / or by providing grooves of the same volume, the rate at which substrate is dispensed onto the crop may be more accurately and reliably controlled. This may help to reduce the amount of substrate that is wasted during the crop treatment process, which may reduce costs. In some embodiments, the conveyor belt arrangement comprises one or more side walls. Preferably the conveyor belt arrangement comprises a pair of side walls, wherein a respective one of the pair of side walls is arranged on each side of the conveyor belt. This may help to ensure that substrate does not fall off the side of the conveyor belt, thereby helping to reduce waste. The side wall(s) may extend from the collection point to the dispensing point, or may extend along only a portion of this distance. The one or more side walls may be integral to and / or mounted on or relative to the conveyor belt such that the side wall(s) move(s) with the conveyor belt. The side wall(s) may be fixedly mounted in the apparatus such that the one or more side walls do not move with the conveyor belt. One or both of the side walls may be arranged so as to funnel substrate towards the centre of the width of the conveyor belt. In other words, a portion of (at least one of) the side wall(s) may protrude, at least partially in the direction of travel of the conveyor belt, from the edge of the conveyor belt towards the centre of the conveyor belt. In some embodiments, the upper surface of the conveyor belt is concave. This may help to prevent substrate falling off the side of the conveyor belt. In some embodiments, the side walls are arranged so as to restrict the width through which the conveyor belt can move, so as to impart a concave shape to the conveyor belt along at least a portion of the path of the conveyor belt. In some embodiments, the concave shape is provided by the structure of the conveyor belt itself. For example, at least a portion of the conveyor belt may have a maximum thickness at the edges of the width of the conveyor belt, reducing to a minimum thickness at the centre of the conveyor belt. In some embodiments, the one or more grooves are formed by protrusions on the conveyor belt. The protrusions may be concave in a plane parallel to the direction of movement of the conveyor belt, and symmetrical in this plane about an axis perpendicular to the direction of movement of the conveyor belt. It will be appreciated that such an arrangement provides protrusions that have a maximum width (in the direction of movement of the conveyor belt) at their outer edges, and a minimum width at their centre. The protrusions may (e.g. additionally) be concave in a plane perpendicular to the direction of movement of the conveyor belt. The protrusions may have the shape of a waisted half-cylinder. This helps to direct substrate collected by the conveyor belt towards the centre of the grooves formed by the protrusions, so as to reduce the risk of substrate falling off the side of the conveyor belt. In some embodiments, the protrusions comprise substantially planar fins. The upper edge of each fin may be concave in the plane of the fin. This helps to ensure that substrate collected by the conveyor belt is directed towards the centre of the conveyor belt. Preferably the apparatus comprises a sensor array comprising one or more sensors for measuring operational parameters of the apparatus. In some embodiments, the (e.g. sensor array of the) apparatus comprises a speed sensor for detecting the speed of the conveyor. The speed sensor may comprise a rotation sensor arranged to measure the rotational speed of a pulley or the motor of the conveyor. In some embodiments, the (e.g. sensor array of the) apparatus comprises a level sensor arranged to detect the amount (e.g. the volume and / or the weight) of substrate held in the reservoir and / or in the loading chamber. The level sensor may be arranged to provide a binary indication of the amount of substrate held in the reservoir and / or in the loading chamber (e.g. more than a threshold or less than a threshold). The level sensor may be arranged to detect when the reservoir and / or the loading chamber is empty and / or full. The level sensor may be arranged to measure the volume and / or the weight of substrate held in the reservoir and / or in the loading chamber. The level sensor may comprise an infrared sensor, an acoustic (e.g. ultrasonic) sensor, a radar sensor, or an optical sensor. The level sensor may comprise a laser sensor. The level sensor may be arranged to detect the volume of substrate held in the reservoir and / or in the loading chamber using time-of-flight (ToF). The level sensor may comprise a piezoelectric sensor. The level sensor may comprise a capacitive sensor. The sensor array may comprise an output sensor arranged to detect the amount of substrate present at the dispensing point of the conveyor. In some embodiments, the (e.g. sensor array of the) apparatus comprises one or more (e.g. all) of: a temperature sensor, a humidity sensor, and a vibration sensor. The temperature sensor is preferably arranged to detect the temperature within the reservoir and / or in the loading chamber. The humidity sensor is preferably arranged to detect the humidity within the reservoir and / or in the loading chamber. The vibration sensor is preferably arranged to detect vibration of the apparatus (e.g. of the reservoir and / or loading chamber). The vibration sensor may be configured to measure the amplitude and / or frequency of vibration. In some embodiments, the apparatus comprises a positioning module for determining the location of the apparatus. The positioning module may comprise a GNSS module (e.g. a GPS module). In some embodiments, the apparatus comprises a control unit. The control unit is preferably configured to control the operation of the conveyor. Preferably the control unit is configured to control the speed of the conveyor. The control unit may be configured to control the direction of the conveyor. In some embodiments, the control unit is configured to perform a priming operation prior to commencement of the crop treatment process. The priming operation may comprise controlling the conveyor to transport substrate at least from the collection point to the dispensing point. For example, the control unit may control the conveyor belt to perform a full cycle of the path of the conveyor belt. Preferably the control unit is configured to perform the priming operation while the apparatus (e.g. the mobile platform) is stationary, i.e. before it has started to move through the crop. This may help to ensure that substrate is present at the dispensing point when the crop treatment process begins, so as to avoid a section of the crop being missed while substrate is transported from the collection point to the dispensing point. In some embodiments, the control unit is configured to perform an emptying operation. Preferably the emptying operation comprises the control unit controlling the conveyor to operate continuously until the control unit receives a signal (e.g. from the level sensor) indicating that the reservoir is empty. The control unit is preferably configured to communicate with each of the sensors of the sensor array. Preferably each of the sensors of the sensor array is configured to output a respective signal to the control unit representative of a respective measurement or detected parameter. The control unit is preferably configured to use the received signal(s) to control the operation of the conveyor. In some embodiments, the apparatus comprises a transceiver for communicating with a mobile platform on which the apparatus may be mounted or with a remote monitoring centre. The control unit of the apparatus is preferably configured to communicate (e.g. with the mobile platform and / or the remote monitoring centre) via the transceiver. The one or more sensors of the sensor array may be configured to communicate (e.g. with the mobile platform and / or the remote monitoring centre) via the transceiver. Preferably the transceiver comprises a radio transceiver. The parameters detected or measured by the one or more sensors of the sensor array and / or by the one or more sensors of the mobile platform may be processed in order to control or monitor the operation of the apparatus and / or the mobile platform. The detected parameters may be processed by the control unit of the apparatus, or by the control unit of the mobile platform, or by a control unit that is separate from the apparatus and the mobile platform (e.g. a control unit of the remote monitoring centre). Preferably, the control unit is configured to determine a substrate distribution rate representative of the rate at which the apparatus is dispensing substrate. The control unit is preferably configured to determine the substrate dispensing rate using one or more measurements obtained by the sensor array and / or obtained from the mobile platform. The control unit may be configured to determine the substrate distribution rate using: the speed of the conveyor; and a substrate distribution value, representative of an amount of substrate carried by the conveyor. For example, the control unit may determine the substrate distribution rate in grams of substrate dispensed by the apparatus per second, using the speed of the conveyor in rotations per second and a substrate distribution value in grams per full length of the conveyor. The substrate distribution value may be fixed, e.g. according to the geometry of the grooves of the conveyor belt and the frequency of distribution of the grooves along the length of the conveyor belt. The substrate distribution value may be measured, e.g. continuously, by a sensor of the sensor array of the apparatus. The control unit may (e.g. additionally) be configured to determine the substrate distribution rate using the speed of the mobile platform. This may be used to provide a substrate distribution rate indicative of the amount of substrate dispensed per unit length of crop. Preferably the control unit is configured to compare the substrate distribution rate with a target distribution rate. Preferably the control unit is configured to issue a control signal for controlling the operation of the apparatus and / or the mobile platform such that the substrate distribution rate approaches the target distribution rate. Preferably the control signal is used to control the speed of the conveyor. The target distribution rate may be predetermined, e.g. set by a user of the apparatus prior to commencing treatment of a crop. In some embodiments, the control unit is configured, in response to receiving a signal from the level sensor indicating that the reservoir is empty, to issue an alert signal to the remote monitoring centre. Preferably, in response to receiving a signal from the level sensor indicating that the reservoir is empty, the control unit is configured to receive location data from the positioning module representative of the current location of the apparatus. Preferably the control unit is configured to send the location data to the remote monitoring centre, e.g. with the alert signal. This means that the location of the apparatus within a crop, at the point when the substrate ran out, can be flagged. This allows treatment of the crop to be resumed from this location, e.g. once the substrate has been refilled or once another mobile platform comprising an apparatus in accordance with the present invention has been made available and sent to the flagged location. In some embodiments, the apparatus comprises a vibration unit arranged to vibrate one or more of: the reservoir, the loading chamber, and the conveyor. This may help to prevent substrate from becoming clogged, which may reduce the accuracy and reliability of the rate at which substrate is dispensed from the apparatus. Preferably the vibration unit comprises a rotor and a weight, wherein the weight is eccentrically mounted on the rotor. The control unit of the apparatus is preferably configured to control the operation of the vibration unit. In some embodiments, the control unit is configured to operate the vibration unit periodically, i.e. at regular time intervals. This may help to ensure that substrate continues to move through the apparatus so that it may be dispensed at a steady rate. The control unit may be configured to operate the vibration unit in response to receiving a signal from the level sensor indicating that the loading chamber and / or the reservoir is empty. This may help to dislodge substrate that may have become clogged. The control unit may be configured to control the vibration unit so as to adjust the frequency and / or amplitude of the vibration. In some embodiments, the control unit is configured to adjust (e.g. increase) the frequency and / or amplitude of the vibration generated by the vibration unit in response to a signal received from the sensor array. For example, the control unit may be configured to increase the amplitude of the vibration in response to receiving a signal from the level sensor indicating that the reservoir and / or the loading chamber is empty. In some embodiments, the apparatus comprises a moveable member arranged to sweep a path within the reservoir. This may help to ensure that substrate continues to move through the apparatus so that it may be dispensed at a steady rate. Preferably the moveable member is arranged to sweep across the width and / or the length of the reservoir. Preferable the moveable member extends along the length of the reservoir. The moveable member is preferably arranged to move reciprocally (e.g. from side to side). The apparatus preferably comprises an actuator for moving the moveable member. The actuator may comprise a motor. The moveable member is preferably elongate. The moveable member is preferably flexible. The moveable member may comprise carbon fibre. In some embodiments, the moveable member comprises Teflon (e.g. a Teflon cover). It will be appreciated that the moveable member and the vibration unit may thus perform a similar function. The moveable member may be provided in combination with the vibration unit The moveable member may be provided as an alternative to the vibration unit. The reservoir may be plastic. The reservoir is preferably manufactured from aluminium. In some embodiments, the reservoir is anodised. This may help to reduce the coefficient of friction within the reservoir, allowing the substrate to flow more easily towards the loading aperture. The apparatus may comprise an assistance mechanism for moving substrate within the reservoir towards the loading aperture. The assistance mechanism may comprise any suitable arrangement. In some embodiments, the assistance mechanism comprises a leadscrew. The assistance mechanism may comprise one or more wipers arranged to sweep substrate towards the loading aperture. The assistance mechanism may comprise the moveable member that is arranged to sweep a path within the reservoir. Preferably the reservoir comprises a floor that is inclined downwardly (towards the base of the reservoir) such that substrate held within the reservoir falls under the action of gravity towards the base and the loading aperture. This helps to assist the flow of substrate through the apparatus, without requiring additional substrate carrying means. Preferably the apparatus comprises a casing defining the floor of the reservoir. The casing may (e.g. additionally) define a roof of the reservoir. The roof may help to protect substrate contained within the reservoir from contamination, e.g. by rainwater. Preferably the reservoir comprises one or more side walls extending upwardly, e.g. from the floor of the reservoir. The casing may define the one or more side walls, e.g. extending upwardly from the lower casing. The one or more side walls may help to ensure that substrate does not fall out of the reservoir, thereby helping to reduce waste. The one or more side walls are preferably shaped so as to funnel substrate towards the loading aperture. The loading aperture may be defined in the floor of the reservoir and / or in a side wall of the reservoir. Preferably the loading aperture is defined at the lowest point of the reservoir (i.e. the furthermost point to which substrate held within the reservoir may fall under the action of gravity). This helps to ensure that as much of the substrate as possible is directed through the loading aperture, meaning that the need for the reservoir to be manually emptied (e.g. in order to refresh the supply of substrate in the reservoir) may be reduced. In some embodiments, the reservoir comprises an evacuation aperture for manually emptying the reservoir. Preferably the apparatus comprises a removable cap arranged to close the evacuation aperture. Preferably the evacuation aperture is arranged at the base of the reservoir, such that substrate is arranged to fall through the aperture under the action of gravity (e.g. when the removable cap is removed). The removable cap may be completely removable. Preferably the removable cap is hingedly mounted on the apparatus, i.e. preferably the removable cap is hingedly moveable to open and close the evacuation aperture. In some embodiments, the reservoir comprises a filling aperture for filling the reservoir with substrate. The filling aperture is preferably arranged at the opposite end of the reservoir to the loading aperture. This may increase the ease with which the entire reservoir can be filled. Preferably the apparatus comprises a removable cap arranged to close the filling aperture. As the loading chamber is arranged below the loading aperture, and is in communication with the reservoir via the loading aperture, the loading chamber is arranged to receive substrate falling through the loading aperture under the action of gravity. This may reduce the need for additional substrate moving means to be provided in order to transport the substrate from the reservoir to the loading chamber. The aperture provides a restriction between the reservoir and the loading chamber that may help to decouple the substrate in the loading chamber from the weight of the substrate in the reservoir. The loading chamber may be arranged directly below the reservoir. However, in some embodiments, the loading chamber is arranged to a side of the reservoir (and below the reservoir). In such embodiments, preferably the loading aperture is defined in a side wall of the reservoir. This means that substrate that is directed through the loading aperture is directed at least partially horizontally (with respect to gravity), which helps to further decouple the substrate in the loading chamber from the weight of the substrate in the reservoir. Preferably the volume of the loading chamber is less than the volume of the reservoir. This helps to provide a buffer volume of substrate that is lighter than the total volume of substrate contained within the apparatus, thereby helping to reduce the shear forces exerted on the substrate as it is collected by the conveyor. The loading chamber preferably comprises a floor that defines the loading port. Preferably the floor of the loading chamber is inclined downwards from the loading aperture towards the base of the loading chamber such that substrate within the loading chamber falls under the action of gravity towards the base and the loading port. Preferably the floor of the loading chamber is inclined at a gradient that is steeper than the gradient at which the floor of the reservoir is inclined. This means that substrate can flow through the loading chamber, under the action of gravity, at a greater speed than substrate flowing through the reservoir. This may help to reduce the likelihood of the loading chamber becoming clogged. In some embodiments, the floor of the loading chamber comprises a first portion and a second portion, wherein the second portion extends downwardly from the first portion and wherein second portion is inclined at a steeper gradient than the first portion. This means that substrate may flow down the second portion, under the action of gravity, at a greater speed than substrate flowing down the first portion, thereby helping to decouple the substrate flowing down the second portion from the substrate flowing down the first portion. Preferably the loading port is defined in the second portion of the floor of the loading chamber. This means that substrate that is collected by the conveyor at the collection point below the loading port may be decoupled from the weight of the substrate flowing down the first portion of the floor of the loading chamber, thereby helping to reduce the shear forces exerted on the collected substrate. In some embodiments, the second portion of the floor of the loading chamber is convex. The collection point of the conveyor is preferably arranged directly below the loading port. Minimising the distance between the loading port and the collection point may help to reduce damage sustained by the substrate as a result of the fall from the loading port to the collection point of the conveyor. In some embodiments, the apparatus comprises a dosing lip arranged to set a maximum height of substrate that can be carried by the conveyor. Preferably the dosing lip is arranged to separate (“shave off’) substrate lying above the set maximum height from substrate lying below the set maximum height, such that substrate lying above the set maximum height is not transported by the conveyor (further) towards the dispensing point. This helps to ensure that the conveyor provides a uniform volume of substrate, e.g. a uniform volume per unit length of the conveyor belt. Preferably the dosing lip is arranged above the conveyor. Preferably the dosing lip is arranged between the collection point and the dispensing point of the conveyor. Preferably the dosing lip is arranged within the loading chamber. This means that substrate that is shaved off by the dosing lip may be retained within the loading chamber and subsequently collected by the conveyor, thereby helping to reduce waste. In some embodiments, the dosing lip at least partly defines the loading port. The dosing lip may define an edge of the loading port. The dosing lip may comprise a tapered surface that extends in a direction substantially opposite to the direction in which the substrate is transported by the conveyor. This may help to separate substrate lying above the maximum height from the substrate lying below the maximum height. In some embodiments, a lower surface of the dosing lip may be inclined at an acute angle with respect to the upper surface of the conveyor belt. Preferably the dosing lip is arranged on the apparatus such that the maximum height set by the dosing lip can be adjusted. The dosing lip may be removable, e.g. so as to be interchangeable. The dosing lip may be hingedly mounted, e.g. within the loading chamber. Providing a dosing lip that can be adjusted so as to vary the maximum height may allow the dose provided by the apparatus to be finely tuned, e.g. for different types of substrate. In some embodiments, the dosing lid comprises one or more ports for directing substrate towards the centre of the conveyor. This may help to reduce the likelihood of substrate falling off the side of the conveyor, thereby helping to reduce waste. The port(s) may comprise a recess and / or a protrusion defined in the dosing lid. In some embodiments, the dispensing point is arranged above the collection point, such that the conveyor is arranged to lift the substrate against the action of gravity. In embodiments in which the conveyor comprises a conveyor belt arrangement, the dispensing point is preferably located at the end of the path of the conveyor belt. This means that substrate may be dispensed onto the crop when the substrate falls off the end of the conveyor belt. In some embodiments, the apparatus comprises a deflector for deflecting substrate off the conveyor belt. The deflector is preferably arranged at the dispensing point for deflecting substrate off the conveyor belt onto the crop. In some embodiments, the deflector is arranged beyond the dispensing point. This may help to remove residual substrate from the conveyor belt before the conveyor belt returns to the collection point. In some embodiments, the deflector comprises a forced gas flow device arranged to direct a stream of gas (e.g. air) to deflect substrate off the conveyor belt onto the crop. The deflector may comprise a brush. The deflector may extend across the width of the conveyor belt. The deflector is preferably inclined, relative to the direction of movement of the conveyor belt, in a plane parallel to the surface of the conveyor belt. This means that substrate carried by the conveyor belt is pushed across the width of the conveyor belt by the deflector as the substrate is carried by the conveyor belt. As will be appreciated by those skilled in the art, any aspect of the present invention described herein can, and preferably does, include any one or more or all of the preferred and optional features of other aspects of the present invention, as appropriate. Certain preferred embodiments for the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows a strawberry plant treatment robot comprising a dispensing tool 2 in accordance with an embodiment of the present invention; Figure 2 shows a semi-exploded view of the dispensing tool of Figure 1; Figure 3 shows a cross-sectional view of the loading chamber of the dispensing tool of Figure 1; Figure 4 shows a schematic of the control arrangement of the strawberry plant treatment robot of Figure 1; Figure 5 shows a further cross-sectional view of the loading chamber shown in Figure 3; Figure 6 shows a perspective view of the base of the loading chamber shown in Figure 3; Figure 7 shows a schematic cross-sectional view of the dispensing tool of Figure 1; Figure 8 shows a perspective view of the top portion of the dispensing tool of Figure 1; and Figures 9a to 9e show perspective and cross-sectional views of alternative geometries for the conveyor belt of the dispensing tool of Figure 1. Figure 1 shows a strawberry plant treatment robot 1 comprising a substrate dispensing tool 2 in accordance with an embodiment of the present invention. The robot 1 comprises an arched body 4 and four motorised wheels 6. The robot 1 is arranged to travel along a row of planters (not shown) in which a crop of strawberries has been planted, with each leg of the arched body 4 traversing a respective side of the planters. The arched body 4 defines a central channel 7 through which a planter can pass when the robot 1 moves along the row. The substrate dispensing tool 2 is mounted on the arched body 4 such that, in use, the dispensing tool 2 is directly above the strawberry plants growing in the planters. The dispensing tool 2 comprises an aluminium casing 8, defining a reservoir (not shown in Figure 1) for holding a substrate to be dispensed onto the crop of strawberries. The casing 8 comprises a filling aperture 10 by which the reservoir can be filled with substrate between operations. The dispensing tool 2 follows the shape of the arched body 4 along a portion of one side of the arch, extending from the crest 4a of the arch to the edge 4b of the arch. The casing 8 consequently has a substantially arcuate cross-section, in the plane in which the arch of the arched body 4 is defined. The filling aperture 10 is arranged at the highest point of the casing 8, at the crest of the arched body 4. This means that the entire volume of the reservoir can be filled. The robot 1 also comprises a blower 38 mounted on the arched body 4. The blower 38 is mounted on the crest of the arched body 4 at the opposite side of the robot 1 to the dispensing tool 2. In other words, the blower 38 is mounted on the leading edge of the arched body 4, while the dispensing tool 2 is mounted on the trailing edge (relative to the direction of travel of the robot 1). The blower 38 is arranged to direct a stream of air towards the crop of strawberries below. The blower 38 helps to remove dead plant matter from the crop of strawberries. This may reduce the risk of the crop becoming infected, and may also improve the effectiveness of predatory mites contained within the substrate that is dispensed onto the crop by the dispensing tool 2, as the mites may be able to access the pests more easily. The stream of air produced by the blower 38 may also help to remove pests themselves from the strawberry plants. Thus, the blower 38 may perform a ‘first pass’ pest removal operation, before a ‘second pass’ of predatory mites are dispensed onto the crop by the dispensing tool 2. Figure 2 shows a semi-exploded view of the dispensing tool 2 of Figure 1. The casing 8 comprises a lower casing 8a, mounted below the reservoir 12, and an upper casing 8b, mounted above the reservoir 12. The upper casing 8b defines the filling aperture 10. The filling aperture 10 comprises a cover 10a for sealing the filling aperture 10 when the aperture 10 is not being used to fill the reservoir 12. This helps to keep the substrate dry. The lower casing 8a defines a dispensing aperture 18 through which substrate is dispensed onto the crop, as will be described in more detail below. The dispensing aperture 18 is arranged in the lower casing 8a at the highest point of the casing 8, i.e. directly below the crest 4a of the arched body 4 of the robot 1. The reservoir 12 slopes downwardly from the filling aperture 10, following the shape of the arched body 4 on which the dispensing tool 2 is mounted. This means that substrate in the reservoir 12 naturally flows to the bottom of the reservoir 12 under the action of gravity. Vibrations caused by the motion of the robot 1 through the crop to be treated may assist with this movement of the substrate by loosening any substrate that may becomes stuck in the reservoir 12. The dispensing tool 2 further comprises a loading chamber 14 that is connected to the reservoir 12 via a loading aperture 14a. The reservoir 12 comprises a first side wall 12a and a second side wall 12b. The loading aperture 14a is defined in the second side wall 12b of the reservoir 12, at the lowermost point of the reservoir 12. The first side wall 12a slopes towards the second side wall 12b at the base of the reservoir 12, where the loading aperture 14a is defined. Thus, the first side wall 12a acts to funnel substrate towards and through the loading aperture 14a, into the loading chamber 14. As the loading aperture 14a is defined in a side wall 12b of the reservoir 12, rather than the bottom of the reservoir 12, the substrate is forced to flow laterally through the loading aperture 14a under the action of gravity, rather than only vertically. This helps to decouple the weight of the substrate within the loading chamber 14 from the weight of the substrate remaining in the reservoir 12. As is described in more detail below, this helps to reduce the damaging shear forces acting on the substrate when the substrate is collected for distribution. Figure 3 shows a cross-sectional view of the loading chamber 14 of the dispensing tool 2 of Figure 1. The base 15 of the loading chamber 14 slopes downwardly from the loading aperture 14a, thereby helping to direct substrate received from the reservoir 12 through the loading chamber 14. The base 15 of the loading chamber 14 comprises a first portion 15a and a second portion 15b. The second portion 15b slopes downwardly at a steeper gradient than the first portion 15a, such that a dosing lip 13 is defined at the intersection of the first portion 15a and the second portion 15b. The respective slopes of the first portion 15a and the second portion 15b of the base 15 of the loading chamber 14 are both steeper than the slope of the reservoir 12, meaning that substrate can flow through the loading chamber, under the action of gravity, at a greater speed than substrate flowing through the reservoir 12. This may help to reduce the likelihood of the loading chamber 14 becoming clogged. The base 15 further comprises a loading port 15c, defined in the second portion 15b of the base 15. The loading port 15c extends downwardly from the dosing lip 13 such that substrate that is directed through the loading chamber 14 can fall through the loading port 15c. The falling substrate is thus effectively decoupled from the substrate remaining in the loading chamber 14, which may be beneficial for collecting the substrate from the loading chamber 14 without damaging it, as will be described in more detail below. The dispensing tool 2 further comprises a conveyor belt 16 that extends from the base of the tool 2 to the highest point of the casing 8. The conveyor belt 16 is mounted on a brushless electric motor 20 such that the turning point of the conveyor belt 16 around the motor 20 is below the loading port 15c. This means that substrate falling through the loading port 15c falls onto the conveyor belt 16 at the collection point 16b of the conveyor belt 16. As the falling substrate is decoupled from the rest of the substrate in the loading chamber 14, the substrate is not subjected to shearing forces resulting from the weight of the substrate in the loading chamber 14 when the falling substrate is collected and carried by the conveyor belt 16. This is particularly beneficial when the substrate comprises predatory mites, which may be damaged by shearing forces, thereby reducing their effectiveness. The conveyor belt 16 comprises a plurality of grooves 16a that are spaced along the conveyor belt 16 at regular intervals. Each groove 16a defines an equally-sized volume for receiving substrate that falls through the loading port 15c. Thus, the grooves 16a help to transport the substrate along the path of the conveyor belt in substantially uniform quantities, at a reliably determinable frequency. The tool 2 further comprises a level sensor 22, comprising an ultrasonic sensor, arranged adjacent the loading port 15c to detect the presence of substrate within the loading chamber 14. The level sensor 22 is connected to a control unit (not shown in Figure 3) which may be used to control the operation of the robot 1 and, more particularly, the dispensing tool 2. Figure 4 shows a schematic of the control arrangement of the plant treatment robot 1 of Figure 1. The robot 1 comprises a central processing unit (CPU) 30 that controls the operation of the wheels 6 of the robot 1 according to configuration settings input by a user of the robot 1. The configuration settings depend on the layout of the crop to be treated, and the desired treatment parameters (e.g. the type of treatment(s) to perform, the speed of treatment, the time of day for treatment, etc.). The CPU 30 receives signals from, and sends signals to, a radio transceiver 32. The CPU 30 uses the radio transceiver 32 to communicate with a robot management server (not shown), which oversees the operation of the robot 1 and any other robots that are treating the crop. The robot 1 further comprises a GPS positioning module 31 that may be used by the CPU 30 to determine the location of the robot 1 within the crop. The CPU 30 also controls operation of the blower 38 mounted on the arched body 4 of the robot 1. The dispensing tool 2 comprises a control unit 34, that communicates with the CPU of the robot 1 via a wired connection. The control unit 34 controls the speed of the electric motor 20, which actuates the conveyor belt 16. This speed may be set using the known volume of each groove 16a, the speed of movement of the robot 1 along the row of planters (obtained from the CPU 30), and the desired dose of substrate per meter (defined in the configuration settings set by the user), to ensure that the substrate is dispensed onto the crops with the correct distribution. The control unit 34 also receives signals from the level sensor 22 to detect whether the loading chamber 14 contains substrate. In the event that the signal received from the level sensor 22 indicates that the loading chamber 14 is empty, the control unit 34 issues a flag to the CPU 30, which reports to the robot management server the location in the crop at which the loading chamber 14 became empty, using positioning data obtained from the positioning module 31. The robot management server may then instruct the robot 1 to return to this location to resume the crop treatment, after the reservoir 12 has been refilled, or instruct a different robot to commence treatment from this location. The dispensing tool 2 further comprises a vibration motor 36, arranged to vibrate the casing 8 of the dispensing tool 2, and a wiper motor 40. The wiper motor 40 is connected to a flexible rod the sweeps across the reservoir 12, as discussed in more detail below. The vibration motor 36 and the wiper arrangement may help to dislodge substrate in the event that substrate has become clogged within the casing. The control unit 34 may initialise the vibration motor 36 and / or the wiper motor 40 upon detecting, using the level sensor 22, that the loading chamber 14 is empty. Figure 5 shows a further cross-sectional side view of the loading chamber 14 shown in Figure 3, and Figure 6 shows a perspective view of the base of the loading chamber 14. The lower surface 13a of the dosing lip 13 extends back on itself, in the direction in which substrate is carried by the conveyor belt 16, towards the upper surface of the conveyor belt 16. The lower surface 16e of the dosing lip 13 is inclined with respect to the upper surface of the conveyor belt 16 so as to define an acute angle a between the lower surface 13a of the dosing lip 13 and the upper surface of the conveyor belt 16. This helps to funnel substrate that has been collected by the conveyor belt 16, having falling through the loading port 15c, towards a restriction 17, at the narrowest point between the dosing lip 13 and the conveyor belt 16. The restriction 17 helps to define a maximum volume of substrate that may be carried within each groove 16a of the conveyor belt 16, which helps to ensure a constant rate of distribution of the substrate by the tool 2. The loading chamber 14 comprises an emptying aperture 19, covered by a cap 19a, at the base of the loading chamber 14. The cap 19a is removable in order to allow the substrate within the loading chamber 14 to be evacuated through the emptying aperture 19. The cap 19a can be seen more clearly in Figure 6. For clarity, the reservoir 12 and the conveyor belt 16 are not shown in Figure 6. The loading chamber 14 further comprises a viewing window 25 that allows a user to see the operation of the conveyor belt 16 and, in particular, to determine whether the flow of substrate is blocked and / or whether the loading chamber 14 is empty. Figure 7 is a schematic cross-sectional view of the dispensing tool 2 of Figure 1, and Figure 8 is a perspective view of the top portion of the dispensing tool 2 of Figure 1. Elements of the casing 4 and the conveyor grooves 16a have been removed from Figure 8 for clarity. The wiper motor 40 is mounted at the top of the reservoir 12, near the filling aperture 10. The motor 40 is arranged to move a moveable member 42 in a sweeping motion across the width of the reservoir 12. The moveable member 42 is flexible, comprising a carbon fibre rod with a Teflon cover. The moveable member 42 extends down the length of the reservoir 12 from the motor 40. This wiper arrangement (comprising the wiper motor 40 and the connected movable member 42) helps to encourage the flow of substrate from the top of the reservoir 12 towards the loading chamber 14, which can help to avoid the reservoir 12 becoming clogged. The conveyor belt 16 extends upwardly from the loading chamber 14 to the dispensing aperture 18 defined in the lower casing 8a of the tool 2. The tool 2 comprises a pulley 24 arranged directly above the dispensing aperture 18. The pulley 24 defines the end of the path of the conveyor belt 16, and is arranged such that substrate falling off the end of the conveyor belt 16, at a dispensing point 16c of the conveyor belt 16, falls through the dispensing aperture 18, and onto the crop 26 below. The dispensing tool 2 further comprises a brush 28 arranged to contact the conveyor belt 16 on the underside of the pulley 24, so that any substrate remaining on the conveyor belt 16 beyond the dispensing point 16c is brushed off, through the dispensing aperture 18. Figures 9a to 9e show perspective and cross-sectional views of alternative geometries for the conveyor belt 16 of the dispensing tool 2 of Figure 1. Each of the alternative geometries allows the substrate being transported by the conveyor belt to be centred on the belt, thereby reducing the risk of substrate falling off the sides of the conveyor belt. This helps to ensure that a consistent dose is delivered by the dispensing tool 2. Figure 9a shows a flat conveyor belt 116 comprising side walls 121 on either side of the conveyor belt 116. The side walls 121 extend along the length of the conveyor belt 116, from the collection point 16b to the dispensing point 16c. Figure 9b shows an embodiment that is similar to that shown in Figure 9a. The conveyor belt 216 is flat and comprises side walls 221. However, in the embodiment shown in Figure 9b, the side walls 221 project inwardly towards the centre of the conveyor belt 216, thereby acting to funnel substrate towards the centre of the conveyor belt 216. Furthermore, the walls 221 are fixedly mounted in the loading chamber 14 at the collection point 216b of the conveyor belt 216 so, unlike the side walls 121 of the embodiment of Figure 9a, the side walls 221 do not move with the conveyor belt 216. Figure 9c shows a conveyor belt 316 comprising side walls 321 arranged between the collection point 316b and the dispensing point (not shown) of the conveyor belt 316. The side walls 321 restrict the width through which the conveyor belt 316 can travel, and therefore act to bend the conveyor belt 316 to form a symmetrically concave cross-section along the length of the side walls 321, between the collection point 316b and the dispensing point. After passing through the dispensing point, the bend in the conveyor belt 316 is released, owing to the absence of the side walls 321 along the return path of the conveyor belt 316, such that the conveyor belt 316 flattens (as shown in the lower portion of the cross-sectional view in Figure 9c). Figure 9d shows an embodiment that is similar to that shown in Figures 3 and 5, in that the conveyor belt 416 comprises a plurality of grooves 416a distributed at regular intervals along the length of the conveyor belt 416. The grooves 416a are formed by protrusions 421 that are concave in a plane parallel to the direction of movement of the conveyor belt 416, and symmetrical in this plane about an axis perpendicular to the direction of movement of the conveyor belt 416. The protrusions 421 have a maximum width (in the direction of movement of the conveyor belt) at their outer edges, and a minimum width at the centre of the conveyor belt 416. The protrusions 421 are also concave in a plane perpendicular to the direction of movement of the conveyor belt 416. The protrusions 421 thus have the shape of a waisted half-cylinder. Thus, the protrusions 421 are shaped so as to direct substrate on the conveyor belt 416 towards the centre of each of the 5 grooves 416a. Figure 9e shows a flat conveyor belt 516 comprising a plurality of fins 521 protruding perpendicularly from the plane of the conveyor belt 516, so as to define a plurality of regularly-spaced grooves 516a therebetween. The upper edge of each 10 of the fins 521 is symmetrically concave so that substrate collected by the conveyor belt 516 at the collection point 516b is directed towards the centre of the conveyor belt 516.

Claims

1. An apparatus for dispensing a substrate onto a crop, the apparatus comprising:a reservoir for holding a substrate, the reservoir comprising a loading aperture defined at a base of the reservoir;a loading chamber arranged below the loading aperture and in communication with the reservoir via the loading aperture, the loading chamber comprising a loading port at a base of the loading chamber; anda conveyor comprising a collection point and a dispensing point, wherein the collection point is arranged below the loading port so as to collect substrate falling through the loading port, and wherein the conveyor is arranged to transport the collected substrate to the dispensing point of the conveyor, where the substrate is dispensed onto a crop.

2. The apparatus of claim 1, wherein the conveyor comprises a conveyor belt arrangement comprising a motor, one or more pulleys, and a conveyor belt.

3. The apparatus of claim 2, wherein the conveyor belt defines a plurality of grooves for holding the substrate.

4. The apparatus of claim 3, wherein the plurality of grooves are spaced at regular intervals along the length of the conveyor belt.

5. The apparatus of claim 3 or 4, wherein the plurality of grooves are of equal volume.

6. The apparatus of any of claims 2 to 5, wherein the conveyor belt arrangement comprises a pair of side walls, wherein a respective one of the pair of side walls is arranged on each side of the conveyor belt.

7. The apparatus of claim 6, wherein the pair of side walls are arranged so as to funnel substrate towards the centre of the width of the conveyor belt.

8. The apparatus of any preceding claim, wherein the apparatus comprises:a speed sensor for detecting the speed of the conveyor; anda control unit, wherein the control unit is configured to determine a substrate distribution rate representative of the rate at which the apparatus is dispensing substrate using:the speed of the conveyor; anda substrate distribution value, representative of an amount of substrate carried by the conveyor.

9. The apparatus of claim 8, wherein the control unit is configured to: compare the substrate distribution rate with a target distribution rate;andissue a control signal for controlling the speed of the conveyor such that the substrate distribution rate approaches the target distribution rate.

10. The apparatus of any preceding claim, further comprising a vibration unit arranged to vibrate one or more of: the reservoir, the loading chamber, and the conveyor.

11. The apparatus of any preceding claim, further comprising an elongate moveable member that extends along the length of the reservoir, wherein the moveable member is arranged to move reciprocally so as to sweep a path within the reservoir.

12. The apparatus of any preceding claim, wherein the loading chamber comprises a floor that defines the loading port, and wherein the floor of the loading chamber is inclined downwardly from the loading aperture towards the base of the loading chamber such that substrate within the loading chamber falls under the action of gravity towards the base and the loading port.

13. The apparatus of claim 12, wherein the reservoir comprises a floor that is inclined downwardly such that substrate held within the reservoir falls under the action of gravity towards the base of the reservoir and the loading aperture, and wherein the floor of the loading chamber is inclined at a gradient that is steeper than the gradient at which the floor of the reservoir is inclined.

14. The apparatus of claim 12 or 13, wherein the floor of the loading chamber comprises a first portion and a second portion, wherein the second portion extends downwardly from the first portion, and wherein the second portion is inclined at a steeper gradient than the first portion.

15. The apparatus of any preceding claim, wherein the loading aperture is defined in a side wall of the reservoir.

16. The apparatus of any preceding claim, further comprising a dosing lip arranged above the conveyor so as to set a maximum height of substrate that can be carried by the conveyor.

17. The apparatus of claim 16, wherein the dosing lip at least partly defines the loading port.

18. The apparatus of claim 16 or 17, wherein the dosing lip comprises a tapered surface that extends in a direction substantially opposite to the direction in which the substrate is transported by the conveyor.

19. A mobile platform comprising a body and an apparatus as claimed in any preceding claim, wherein the apparatus is mounted on the body of the mobile platform.

20. The mobile platform of claim 19, wherein the mobile platform comprises a robotic crop treatment device.

21. The mobile platform of claim 19 or 20, wherein the body of the mobile platform comprises:a pair of parallel walls defining an open channel therebetween; andan arch extending from an upper surface of a first of the parallel walls to an upper surface of a second of the parallel walls, wherein the arch comprises a crest at the highest point of the arch;and wherein the apparatus is curved such that the apparatus follows the curve of the arch of the body of the mobile platform, and wherein the apparatus is mounted on the body such that the apparatus extends downwardly from the crest of the arch.

22. The mobile platform of claim 21, wherein the apparatus is mounted on the body such that the dispensing point of the conveyor is adjacent the crest of the arch.

523. The mobile platform of any of claims 19 to 22, further comprising an ultraviolet treatment tool for treating crops with ultraviolet light, wherein the apparatus is mounted on the body of the mobile platform such that it is offset from the ultraviolet treatment tool in the direction of travel of the mobile platform.1024 The mobile platform of any of claims 19 to 23, wherein the mobile platform further comprises a forced air flow device arranged to direct a flow of air onto the crop.15 25. The mobile platform of claim 24, wherein the apparatus is mounted on thebody of the mobile platform such that it is offset from the forced air flow device in the direction of travel of the mobile platform.

Images