Pesticide sprayer and sprayer nozzle

Abstract

There is a pesticide sprayer 100 figure 1 and sprayer nozzle 105 for coating vegetation with liquid droplets of pesticide. The sprayer comprises a plurality of sprayer nozzles arranged as a bank 110 of sprayer nozzles. Each sprayer nozzle is individually supplied with pesticide liquid from a common reservoir. A first airflow means 120 for providing a stream of air to each sprayer nozzle is provided. There is a second airflow means 125 for providing a stream of air around each sprayer nozzle.

Description

Field of the invention The present disclosure relates to a foliar application sprayer and sprayer nozzle for coating vegetation with liquid droplets of bioactive compounds. In particular, the present disclosure relates to a low power consumption foliar application sprayer comprising a plurality of moveable sprayer nozzles with at least one sensor, a control system, and two airflow means wherein the sprayer nozzles comprise a nozzle housing, rotary atomiser, airflow pathway, and liquid pathway. Background To ensure that crops are grown and harvested quickly and efficiently for optimal value the crops need to be protected from pests and diseases. To protect the crops from such dangers, pesticide sprays are used. To reduce the time required to spray crops, large scale industrial mechanical automotive devices are used to cover large areas of crops quickly. Most of these large-scale pesticide spraying devices focus on efficiency of time spent spraying crops and, therefore, spray an abundant amount of pesticide liquid onto multiple crops instantly by way of multiple sprayer nozzles. The size and consumption of these devices cause large amounts of pesticide liquid to be released, more than is necessary to protect from pests and disease. As a result, pesticide liquid is wasted by these devices on saturated crops. Furthermore, the large size of these spraying devices can cause damage to the ground upon which they operate. Other devices focus on reducing the amount of pesticide liquid used for a certain area of crops by enhancing the precision and spray rates of liquid pesticide from the pesticide sprayer device. Recent concerns have highlighted the toxicity of liquid pesticides to wildlife, humans, and naturally occurring ecosystems. The need to reduce any unnecessary use of these liquids is becoming prominent. Moreover, there is growing concern over the high energy usage rendered by industrial pesticide sprayers. In the current atmosphere of climate change high energy usage devices are deemed bad for the environment. Furthermore, most conventional pesticide sprayer devices rely heavily on petrol or diesel fuel. While some pesticide spraying devices are turning to electrical energy, the high-power consumption of the device typically requires the need for a constant connection to power means. EP3313179 describes an example compact sprayer device, sprayer system and system and method for the control of a plurality of said sprayer device. However, this device requires a pump such as a peristaltic pump to be located in each sprayer nozzle in addition to a fan drive system. This can result in high electrical power consumption. WO2011048593A1 describes a method, equipment, and devices for adjusting the distance and directions of air jets carrying droplets of plant treating liquid and the controlled liquid flow rate, in order to evenly cover different targets of the plant's canopy with the right amounts of droplets needed by each target, without drift to the environment. CA1258834A describes a spray unit and process for controlled droplet atomization in which a tangential vortex type fan with wide mouth passes operation from low-to-medium pressures at high volume, passes air through a throat in which controlled droplet atomization of spray material is being achieved prior to emission from the fan in a plane generally parallel to the flow of air. US4619401A describes a controlled droplet applicator for applying fluid in droplet form to a target area. The applicator includes a rotary atomizer for generating fluid droplets of a selected size and density, and a propellor fan for rotating with the atomizer and for causing the fluid droplets to move toward the target area. US11453019B2 describes a handheld sprayer comprising a spray nozzle assembly that is configured to atomize and spray liquid from a housing assembly, and blowout air flow generated by a fan assembly. Baltazar et al., "Smarter Robotic Sprayer System for Precision Agriculture" (Electronics 2021, 10, 2061) outlines a smart robot platform using rotary atomisation. Summary of the invention Aspects of the invention are as set out in the independent claims and optional features are set out in the dependent claims. Aspects of the invention may be provided in conjunction with each other and features of one aspect may be applied to other aspects. Embodiments of the disclosure are directed towards a foliar application sprayer and sprayer nozzle for coating vegetation with liquid droplets of bioactive compounds, for example, pesticides. Embodiments of the disclosure may advantageously address the aforementioned problems and provide a system that can reduce the quantity of pesticide used, and also be powered by batteries, thus reducing the environmental impact and also weight of the system. A first aspect of the disclosure provides a foliar application sprayer for coating vegetation with liquid droplets of pesticide comprising; a plurality of sprayer nozzles arranged as a bank of sprayer nozzles, each sprayer nozzle individually supplied with pesticide liquid from a common reservoir; a first airflow means for providing a stream of air to each sprayer nozzle; and a second airflow means for providing a stream of air around each sprayer nozzle. Advantageously such a foliar application sprayer may reduce liquid pesticide waste by accurately spraying pesticides by way of two airflow means. The first airflow means may provide an airflow that picks up liquid droplets from the sprayer nozzle and direct them to the target of choice by way of a spray cone whilst the second airflow means may provide a strong axial airflow which provides the droplets with the power to travel the distance to the canopy of choice. This may be advantageous compared to single airflow foliar application sprayers, as the additional airflow means aids the delivery of the liquid droplets to a specific location. Further advantageously, the foliar application sprayer may still operate effectively during imperfect or windy weather. This is possible because the second airflow means may neutralise turbulence about the sprayer nozzle end and allows liquid pesticide to be picked up by the first airflow means without interference by stormy winds or rain. The foliar application sprayer may comprise two banks of sprayer nozzles, wherein each sprayer nozzle of each bank is provided with a respective second means for providing a stream of air to each corresponding sprayer nozzle. Advantageously, the banks of sprayer nozzles, which can arrange the sprayer nozzles vertically or horizontally, can supply a larger surface area of canopy with liquid pesticide instantly compared to an individual nozzle. The second airflow means to each sprayer nozzle individually may also allow for greater precision of liquid pesticide delivery to a vegetation canopy, such as vines. Additionally, or alternatively, each bank of sprayer nozzles may be provided with a common or shared second means for providing a stream of air to the bank of sprayer nozzles. Advantageously, the shared or common second airflow means can reduce the power consumption of the foliar application sprayer by reducing the variable components of the system. The communal second airflow may also be advantageous in climates where the canopy is denser and continuous, here the communal second airflow may produce one stream of liquid pesticide spray from the multiple sprayer nozzles. This broader stream of liquid pesticide spray may cover a dense canopy more efficiently compared to individual sprayer nozzles. In some examples, each bank of sprayer nozzles may comprise a set of sprayer nozzles on a spray boom. In examples, each bank of sprayer nozzles is on an opposing side of the foliar application sprayer, and wherein the relative position of each sprayer nozzle on each bank is adjustable vertically, and wherein the relative position of each bank is adjustable horizontally. In other examples, the relative position of each sprayer nozzle may be adjustable horizontally, and wherein the relative position of each bank is adjustable vertically. Advantageously, the foliar application sprayer may be operated in designated alleys between rows of vegetation or crops and spray adjacent rows at the same time. Furthermore, the adjustable positioning of the banks and sprayer nozzles horizontally and / or vertically may allow the foliar application sprayer to adapt to canopy of differing heights or separation without exhausting liquid pesticide supplies unnecessarily. A reduction in unnecessary liquid pesticide application may, advantageously, lessen the liquid stored onboard and the weight of the foliar application sprayer. A reduction in the weight of the foliar application sprayer may diminish the damage inflicted to the designated alleys of crop land and the planted vegetation adjacent to the alleys. The first airflow means may comprise a common fan. Advantageously, the common fan configuration may reduce energy consumption and maintenance demands compared to a foliar application sprayer with a fan in each sprayer nozzle. The first airflow means may be, for example, a centrifugal fan, for example a centrifugal blower fan. This fan is particularly energy efficient and may be of relevance if the foliar application sprayer is to be battery powered. It will, however, be understood that in other examples each first airflow means may comprise a respective fan. That is, each sprayer nozzle may be provided with a stream of air from a first airflow means, which may be a fan. This fan may be, for example, a centrifugal fan, for example a centrifugal blower fan. The second airflow means may comprise a bladeless fan. Advantageously, the use of a bladeless fan may reduce the energy consumption of the foliar application sprayer, using the principle of entrainment, compared to the use of other fans which are mechanically demanding and may introduce turbulent flow. Moreover, the incorporation of a bladeless fan, over fans of a different type, creates a device that may be accessible and easier to maintain and clean. The first and second airflow means may have adjustable speed and power. Advantageously, the combination of the adjustable first and second airflow means may increase or decrease the force at which liquid pesticide is carried and deposited on target canopy. Each sprayer nozzle may comprise a respective atomiser for breaking up the liquid into droplets. Advantageously, the incorporation of an atomiser into each sprayer nozzle to break up liquid reduces liquid being wasted to lengths of connection piping. The atomiser may instantly disintegrate the liquid into ligaments and then into droplets which are ejected from the surface of the atomiser lip, where the rotary atomiser protrudes beyond the nozzle housing. As the liquid is not propelled forwards to create the liquid drops there may be a reduction in liquid lost to the environment by unwanted moving spray. In examples, each sprayer nozzle comprises a respective motor for driving the corresponding atomiser. Preferably, the sprayer nozzles comprise a brushless motor which are advantageously higher in power efficiency. However, the skilled person will understand that the sprayer nozzle may also comprise motors such as, but not limited to, a brushed motor, a servo motor, a universal motor, or a stepper motor. The speed of rotation of each atomiser, via each motor, may be controllable. Each sprayer nozzle may comprise an airflow pathway and a liquid pesticide pathway, wherein the airflow pathway surrounds and is coaxial with the liquid pesticide pathway. Advantageously, the positioning of the airflow pathway around the liquid pesticide pathway can direct the liquid to the target canopy and reduce unwanted spraying outside the target. Each sprayer nozzle may have a proximal end and a distal end, wherein the liquid pesticide and airflow from the first airflow means enter the sprayer nozzle at the proximal end and exit via the distal end, wherein the atomiser is proximal to the distal end, and wherein the atomiser is adjacent to atomiser teeth which are configured to break the liquid pesticide into fine droplets at a distal part of the atomiser, beyond the nozzle, which can be easily moved by low air speeds. Advantageously, the positioning of the atomiser beyond the nozzle housing, forming an atomiser lip, may create a focus point where the liquid droplets are ejected and can be picked up by the airflow means without major reduction in speed or changes to the airflow pathway. The airflow used to pick up the fine liquid droplets may consequently be low in speed rather than high power and high energy consuming airflow. Standard airblast or pneumatic sprayers require airflow speeds of around 120 to 160 km / h whereas this sprayer nozzle may require less than 70 km / h. In examples, the airflow pathway comprises a divergent portion proximate to the proximal end and a convergent portion proximate to the distal end, wherein the cross-sectional area of the airflow pathway reduces from the proximal end to the distal end in the divergent portion, and wherein the liquid pesticide pathway comprises a divergent portion proximate to the proximal end and a convergent portion proximate to the distal end. Advantageously, the adjacent divergent and convergent portions of the airflow pathway which reduce the cross-sectional area, may narrow the airflow, and increase the speed, using the Venturi effect, to the point where the droplets are being created on the lip of the atomiser. The airflow pathway may be configured to speed up the airflow using aerodynamic principles rather than pure power, wherein the liquid droplets on the atomiser may be moved easily and precisely by the converged airflow without the need for additional directional fans. The airflow pathway may comprise optional guide vanes at the distal end of the airflow pathway. Advantageously, the airflow guide vanes may provide a swirling motion to the airflow leaving the airflow pathway to aid with picking up liquid droplets from the atomiser lip that sits inside the circular shaped airflow pathway exit. The airflow may move into the vicinity above and around the lip of the atomiser and provide extra movement to the slow-moving droplets. Furthermore, the airflow guide vanes may be configured to introduce a predetermined amount of turbulence to the air flow, which can cause leaves in the target canopy to move slightly, thereby improving droplet deposition. The airflow guide vanes may, for example, introduce turbulence to airflow exiting the sprayer nozzle. The airflow pathway may comprise optional airflow straighteners at the proximal end of the airflow pathway. Advantageously, the airflow straighteners may reduce turbulence of the airflow and increase its axial speed. For example, the airflow straighteners may reduce the turbulence of the airflow within the sprayer nozzle. The airflow pathway may comprise optional aerodynamic fins throughout its structure. Advantageously, the airflow aerodynamic fins may hold the atomiser fixed in the sprayer nozzle and reduce turbulence of the airflow. For example, the aerodynamic fins may reduce the turbulence of the airflow within the sprayer nozzle. The foliar application sprayer may further comprise a common pump for supplying liquid pesticide to each of the plurality of sprayer nozzles. Advantageously, a common pump may reduce the power required to supply liquid to each individual sprayer nozzle. The common pump may be, for example, a standard pump for example a centrifugal pump. The foliar application sprayer may be in proximity to an optional flow rate sensor to control valves arranged to independently control the flow rate of liquid pesticide to each sprayer nozzle. The flow rate sensor may be advantageous to identify any over expenditure or scarcity of liquid pesticide supply to the sprayer nozzles, in addition to any maintenance issues or leaks in the supply or piping chain to the sprayer nozzle. Advantageously, the control valves may reduce any aforementioned issues by reducing or increasing flow of liquid pesticide to each sprayer nozzle. The individual control of each sprayer nozzle liquid pesticide flow via the control valves may be advantageous for using the foliar application sprayer even when one or more sprayer nozzle is impaired and not operational. The common pump’s supply of liquid pesticide may be adjustable. The speed of rotation of the atomiser and the flow rate of liquid pesticide supplied to the sprayer nozzle may be controlled to control the size and volume of the liquid pesticide droplets produced by the atomiser. Advantageously, droplets of different sizes and volumes may allow lower or higher airflow speeds to be utilised and a greater or smaller liquid pesticide volume to be deposited on the target canopy per second. The pump, first airflow means, and second airflow means of the foliar application sprayer may be coupled to a battery. Advantageously, a battery powered foliar application sprayer may operate over a large area of vegetation or crops away from a mains supply saving time and money spent on driving the foliar application sprayer. The battery may also reduce environmental impact compared to foliar application sprayers powered by fossil fuels. Further advantageously, the use of a battery may reduce the weight of the foliar application sprayer and the power required to move it. A lighter foliar application sprayer lessens the damage inflicted to the designated alleys of crop land and the planted vegetation adjacent to the alleys. Another aspect of the disclosure provides a sprayer nozzle for coating vegetation with liquid droplets of pesticide, the sprayer nozzle comprising: a nozzle housing having a proximal end and a distal end, wherein the housing is configured to receive liquid pesticide and airflow at the proximal end and exit via the distal end, wherein the housing is configured to provide (i) an airflow pathway and (ii) a liquid pesticide pathway, wherein the airflow pathway surrounds and is coaxial with the liquid pesticide pathway, and comprises a divergent portion proximate to the proximal end and a convergent portion proximate to the distal end, wherein the nozzle housing is configured to reduce the cross-sectional area of the airflow pathway from the proximal end to the distal end in the divergent portion; and wherein the liquid pesticide pathway comprises a divergent portion proximate to the proximal end and a convergent portion proximate to the distal end. Advantageously, such a sprayer nozzle may spray liquid pesticide precisely onto a target canopy without wasting unnecessary liquid pesticide. The airflow pathway surrounding the liquid pesticide pathway may create a cone for the liquid pesticide to follow beyond the nozzle housing towards the target canopy. Further advantageously, the sprayer nozzle may spray pesticide onto a target canopy with low energy usage. The diverging airflow portion followed by the converging portion may speed up the airflow and decrease its static pressure via the Venturi effect. The airflow may entrain the liquid pesticide without the need for high-speed fans or fans within each sprayer nozzle. The airflow pathway may comprise optional guide vanes at the distal end of the airflow pathway. Advantageously, the guide vanes may cause the airflow to swirl about, and across, the lip of the atomiser and pick up liquid pesticide droplets in its flow. Furthermore, the vanes may be configured to introduce a predetermined amount of turbulence to the air flow, which can cause leaves in the target canopy to move slightly, thereby improving droplet deposition. The sprayer nozzle may further comprise a rotary atomiser proximal to the distal end of the nozzle housing and coupled to the liquid pesticide pathway. Placing the rotary atomiser proximal to the distal end of the nozzle housing may allow liquid droplets to be efficiently “picked up” and entrained by the airflow with maximum efficiency and accuracy. In examples, the rotary atomiser is adjacent to atomiser teeth which are configured to break the liquid pesticide into fine droplets at a distal part of the atomiser, beyond the nozzle housing, which can be easily moved by low air speeds. Advantageously, the deposition of the liquid pesticide beyond the nozzle, on the lip of the atomiser, may allow the airflow to pick up the liquid droplets without generating undesirable turbulence about the sprayer nozzle exit and reducing airflow speed. The ability to use low air speeds may advantageously reduce energy consumption of the foliar application sprayer fan. Typical airblast sprayers require 31 kW of power whereas this sprayer may function on 1 to 10 kW of power, more preferably 5 kW. The nozzle housing and rotary atomiser may optionally be coupled together by at least one releasable fastening means. The fastening means may be, for example, a clipping mechanism, for example a clip. The convergent distal end of the airflow pathway may be arranged to form a narrow axial spray of liquid pesticide beyond the nozzle housing. Advantageously, a narrow axial spray of liquid pesticide may negate liquid pesticide spraying beyond the boundaries of the chosen target canopy. The bank of sprayer nozzles comprising a plurality of the nozzles may be coupled to a common airflow means for supplying a stream of air to each of the nozzles of the bank of nozzles. The common airflow means may be provided by, for example, a centrifugal fan, for example a centrifugal blower fan. Another aspect of the disclosure provides a sprayer nozzle for coating vegetation with liquid droplets of pesticide, the sprayer nozzle comprising; a nozzle housing having a proximal end and a distal end, wherein the housing is configured to receive liquid pesticide and airflow at the proximal end and exit via the distal end; wherein the housing houses a rotary atomiser proximal to the distal end of the housing and coupled to a liquid pesticide pathway, wherein the rotary atomiser is configured to break up liquid received via the liquid pesticide pathway into droplets; and wherein at least a portion of the rotary atomiser is arranged to sit proud of the nozzle housing which houses the atomiser. Advantageously, the sprayer nozzle may reduce undesirable turbulence about the sprayer nozzle exit and reduce the required airflow speed to pick up and entrain the liquid droplets ejected from the atomiser lip. The ability to use low air speeds may advantageously reduce energy consumption of the foliar application sprayer fan. Further advantageously, the sprayer nozzle may not require a fan within the nozzle housing. Such a “minimalistic” sprayer nozzle may be easier to repair, replace and clean if maintenance issues arise. Each rotary atomiser may be arranged to sit completely, or at least partially, proud of the nozzle housing, for example creating a lip of the rotary atomiser. Advantageously, the rotary atomiser may be easier to repair, replace and clean if maintenance issues arise. Additionally, the atomiser may not interfere with the specialised pathways or streamline nature of the airflow and liquid pesticide. The nozzle housing may be arranged to provide an airflow pathway around the rotary atomiser beyond the nozzle housing and create a Venturi effect to speed up air and entrain droplets from the rotary atomiser. Advantageously, turbulence may be reduced about the atomiser negating the redeposition of liquid droplets on the atomiser or the loss of droplets to the atmosphere. The airflow pathway may comprise a divergent portion proximate to the proximal end and a convergent portion proximate to the distal end, wherein the nozzle housing is configured to reduce the cross-sectional area of the airflow pathway from the proximal end to the distal end in the divergent portion. Advantageously, a reduction in cross-sectional area of the airflow pathway in the convergent portion may increase the airflow pathway speed and lessen the need for high power fans on the foliar application sprayer and negate the need for a fan in each sprayer nozzle. Another aspect of the disclosure provides a sprayer nozzle for coating vegetation with liquid droplets of pesticide, the sprayer nozzle comprising; a nozzle housing having a proximal end and a distal end, wherein the housing is configured to receive liquid pesticide and airflow at the proximal end and exit via the distal end; wherein the airflow pathway passes through the nozzle housing, surrounds and is coaxial with the liquid pesticide pathway, and comprises a divergent portion proximate to the proximal end and a convergent portion proximate to the distal end; and a control system configured to control the speed of airflow and adjust the convergence of the convergent portion. Advantageously, such a sprayer nozzle may be controlled to adapt the amount of airflow convergence from the sprayer nozzle without the need for movable airflow or liquid pesticide pathway chambers. The adjustable convergence of the airflow about the sprayer nozzle may occur by variable airflow speeds alone. The control system may be configured to adjust the angle and distance of projection of liquid pesticide from the distal end of the nozzle housing. Advantageously, the sprayer nozzle may adapt the distance to, and breath of canopy reached by an individual nozzle. The nozzle housing may comprise an atomiser proximal to the distal end of the housing coupled to the liquid pesticide pathway configured to break the liquid into droplets at the distal end of the sprayer nozzle. Advantageously, the converging airflow may pick up the droplets and carry them in their trajectory. The nozzle housing may be configured to reduce the cross-sectional area of the airflow pathway from the proximal end to the distal end in the divergent portion, to converge the airflow pathway around the atomiser, wherein the airflow is configured to pick up the droplets in its flow. Advantageously, a reduction in airflow pathway cross-sectional area allows the airflow to be sped up by the Venturi effect without the need for further fans. In examples, a pump may be configured to provide a variable supply of liquid pesticide and the control system is configured to provide a spray cone of liquid pesticide in the axial direction of the nozzle with a varying width tangential to the axial direction and depth along the axial direction. In examples, the airflow may be provided by a communal fan and flexible air ducts. Another aspect of the disclosure provides a foliar application sprayerfor coating vegetation with liquid droplets of pesticide comprising; a plurality of sprayer nozzles, each sprayer nozzle individually supplied with pesticide liquid from a common reservoir; a first airflow means for providing a stream of air to each sprayer nozzle; a second airflow means for providing a stream of air around each sprayer nozzle; at least one sensor arranged to provide sensor signals indicative of vegetation canopy; and a control system configured to: determine the presence and distance of vegetation canopy based on the sensor signals; and adjust the rate of flow of the second airflow based on the determined presence and distance of the vegetation canopy. An advantage of the present disclosure may be to provide a foliar application sprayer which adjusts its second airflow means to efficiently deliver liquid pesticide spray to target canopy without excessive use of power. The control system may be configured to adjust the rate of flow of the second airflow means based on the determined presence and distance of the vegetation canopy to adjust liquid coverage across the vegetation canopy. Advantageously, canopy that is far away from the sprayer nozzle may be reached while using low power air. The control system may be configured to adjust the rate of flow of the second airflow means based on the surrounding weather conditions to maintain a desired liquid pesticide spray coating on the target vegetation canopy. Advantageously, the amount of liquid pesticide spray that may be wasted is reduced. The second airflow means may comprise a bladeless fan configured to provide a flow of air around each sprayer nozzle. Advantageously, the bladeless fan may provide low power, smooth airflow while maintaining enough propulsion to entrain liquid pesticide droplets. In examples, each sprayer nozzle may comprise a respective atomiser for breaking up the liquid into droplets and wherein the first airflow means is configured to pick up and axially direct the droplets towards the canopy and the second airflow means is configured to project the droplets the distance to the canopy. Advantageously, the combination of atomiser and two airflow means may allow for variable droplet sizes to be produced and moved in a horizontal, forward moving spray at low power. Another aspect of the disclosure provides a foliar application sprayer for coati ng vegetation with liquid droplets of pesticide comprising; a plurality of sprayer nozzles arranged as a bank of sprayer nozzles, each sprayer nozzle individually supplied with pesticide liquid from a common reservoir; at least one sensor arranged to provide sensor signals indicative of vegetation canopy; and a control system configured to: determine the presence and distance of vegetation canopy based on the sensor signals; and adjust the position of the bank of sprayer nozzles based on the determined presence and distance of the vegetation canopy. Advantageously, such a foliar application sprayer can adapt to target canopy and reduce or increase liquid pesticide spray coverage accordingly. Loss of liquid pesticide spray or accidental untreated canopy may be nullified. Further advantageously, the nozzle may be positioned optimally relative to the canopy to ensure that the target canopy is reached even with low powered air. The foliar application sprayer may comprise a control system configured to adjust the position of the bank of sprayer nozzles based on the determined presence and distance of the vegetation canopy to maintain a constant distance between the bank of sprayer nozzles and the vegetation canopy. Advantageously, maintaining a constant distance to vegetation diminishes the need for adaptable fans, pumps, and airflow speed changes or liquid pesticide flow rate changes and in turn reduces maintenance requirements within the sprayer device. The control system may be configured to adjust the relative position of each sprayer nozzle of the bank of sprayer nozzles based on the determined presence and distance of the vegetation canopy. In examples, (i) the relative position of each sprayer nozzle of the bank is adjustable vertically by way of adjustable means, and / or (ii) the relative position of each bank is adjustable horizontally by way of adjustable means. The control system may be configured to determine at least one parameter related to the atmosphere based on the sensor signals received from the at least one sensor, and to control the rate of liquid pesticide release of at least one of (i) the bank of the plurality of sprayer nozzles, or (ii) individual sprayer nozzles, based on at least one parameter related to the atmosphere. Advantageously, controlling the rate of liquid pesticide release from individual, or a group of, sprayer nozzles may allow the minimum amount of liquid to be sprayed when needed but not all the time unnecessarily. Drawings Embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a side plan view of an example pesticide sprayer; Figure 2 shows a side plan view of the same pesticide sprayer as shown in Figure 1 with a different second airflow means; Figure 3 shows a side plan view of a pesticide sprayer similar to those shown in Figure 1 and 2 with at least one sensor and a control system; Figure 4A shows a perspective view of one of the sprayer nozzles shown in Figures 1 to 3; Figure 4B shows a deconstructed perspective view of the sprayer nozzle in Figure 4A ; Figure 4C shows a side plan view of the sprayer nozzle shown in Figures 4A and 4B; Figure 5 shows a simplistic cross-sectional view of the sprayer nozzle as shown in Figures 4A, 4B, and 4C; Figure 6 shows a more detailed cross-sectional view of the sprayer nozzle as shown in Figure 5; Figure 7 shows a more detailed cross-sectional view of the sprayer nozzle as shown in Figures 5 and 6, highlighting the different portions of the airflow pathway; Figure 8 shows a close-up cross-sectional view of the sprayer nozzle distal end as shown in Figures 5 to 7; Figure 9A shows a front on view of the distal end of the sprayer nozzle; Figure 9B shows a front on view of the proximal end of the sprayer nozzle; Figure 10 shows a front on view of the coupling between the sprayer nozzle and second airflow means via aerodynamic fans as seen in Figures 1 to 3; Figure 11A shows a cross-sectional view of the sprayer nozzle as shown in Figures 4 to 10 with a relatively strong airflow; Figure 11B shows a cross-sectional view of the sprayer nozzle as shown in Figures 4 to 11A with a relatively weak airflow; Figure 12 shows a block diagram of the architecture of the control system of the pesticide sprayer as shown in Figure 3; and Figure 13 shows a simplified drawing of the pesticide sprayer. Specific description Embodiments of the claims relate to a pesticide sprayer and sprayer nozzle for coating vegetation with liquid droplets of pesticide. In particular, the present disclosure relates to a low power consumption pesticide sprayer comprising a plurality of moveable sprayer nozzles with at least one sensor, a control system, and two airflow means wherein the sprayer nozzles comprise a nozzle housing, rotary atomiser, airflow pathway, and liquid pesticide pathway. Figure 1 shows an example pesticide sprayer 100. The pesticide sprayer comprises a main central body 150 with two banks 110 on either side of the main central body 150. The main central body 150 comprises first airflow means 120, a pump 145, control valves 140, and a battery 135. The main central body 150 also comprises a reservoir which is not shown in Figure 1. The first airflow means may be provided, for example, by fan units, for example centrifugal blower fans. In examples, the main central body 150 may comprise two first airflow means 120, one for each bank 110, or the main central body 150 may comprise a singular first airflow means 120. The battery 135, pump 145, and control valves 140 are depicted as sitting on a face of the main central body 150, but the skilled person will understand that other positions on or inside the main central body 150 would be appropriate. In examples, the main central body 150 may comprise two or more batteries 135. The two banks 110 are coupled to the main central body 150 and comprise two portions, a supporting arm 110A and a spray boom 110B. The supporting arm 110A is the first portion of the bank 110 and is a horizontal segment, which is coupled to the main central body 150, and in use protrudes away from the main central body 150 parallel to the ground. The spray boom 110B is the second portion of the bank and is a vertical segment, coupled to the support arm 110A, which is positioned perpendicular to the support arm 110A to form an upright limb protruding above the main central body 150 and held at a distance to the main central body 150. The spray boom 110B may also sit horizontally, and perpendicularly to the first portion, to create a structure which aligns with the height of the main central body 150 and reaches in front and behind the main central body 150 at the same height as the main central body 150. The connecting portions between the central main body 150 and the supporting arms 110A and the supporting arms 110A and the spray booms 110B, optionally, are adjustable means. The adjustable means 115 may be provided, for example, by actuators. As shown in Figure 1, the spray booms 110B comprise multiple sprayer nozzles 105 and multiple second airflow means 125. The second airflow means 125 may be provided, for example, by a bladeless fan. The sprayer nozzles 105 are mounted onto the spray booms 110B, are cylindrical in shape, and are described in further detail below by way of Figures 4 to 11. The sprayer nozzles 105 have a distal end which is orientated away from the main central body 150 and a proximal end which individually couples to the main central body 150 by flexible piping 130. The flexible piping 130 optionally comprises a flexible air duct, flexible liquid duct, and / or flexible wiring, or any combination thereof depending on its function. The second airflow means 125 are cylindrical in shape and hollow. The sprayer nozzles 105 are each coupled to the second airflow means 125 by way of optional aerodynamic fins and each second airflow means 125 surrounds at least part of an individual sprayer nozzle 105. The coupling between the sprayer nozzles 105 and second airflow means 125 via aerodynamic fins are arranged equidistantly along the spray booms 110B either a height above the main central body 150 or a distance in front and / or behind the main central body 150. The couplings between sprayer nozzles 105 and second airflow means 125 via aerodynamic fins will be described in more detail in Figure 10. The sprayer nozzles 105 and second airflow means 125 have distal ends which are orientated away from the main central body 150 and proximal ends which, as mentioned before, are individually coupled to the main central body 150 by flexible piping 130. The flexible piping 130 couples sprayer nozzles 105 and second airflow means 125 to the main central body 150. The main central body 150 comprises control valves 140. In Figure 1 the control valves 140 are depicted as being proximal to, or on, the main central body 150 but the skilled person will understand that the control valves 140 may couple to the reservoir or sit at other positions along the flexible piping 130. Not shown in Figure 1 are optional flow rate sensors which may be coupled to the flexible piping 130, for example, at the exit of the pump 145. In other embodiments, the optional flow rate sensors may be coupled to the flexible piping 130 such that there is one per bank 110 of sprayer nozzles 105 or one per sprayer nozzle 105. The main central body 150 is configured to be driven and move along the ground as dictated by a driver or operating system. The battery component 135 on the main central body 150 is configured to charge when the pesticide sprayer 100 is not in use and to provide electrical energy to the pump 145, control valves 140, control system 310, first airflow means 120, second airflow means 125, sprayer nozzles 105, and at least one sensor 305 when in use. In embodiments, the adjustable means 115 may optionally be provided with electrical energy from the battery 135. The pump 145, located on the main central body 150, is configured to draw liquid pesticide from the reservoir, stored in the main central body 150, through the flexible piping 130 to the sprayer nozzles 105. The control valves 140 coupled to the flexible piping 130, main central body 150, or reservoir are configured to regulate the flow of liquid pesticide through the flexible piping 130. The banks 110 are configured to support the sprayer nozzles 105 and second airflow means 125 securely on the moving main central body 150 at a distance above the ground. The first airflow means 120 provides an airflow to the sprayer nozzle 105. The adjustable means 115 on the banks 110 are configured to optionally adjust the positioning of the sprayer nozzles 105 and second airflow means 125 with respect to the main central body 150. These adjustable means 115 may optionally adjust the horizontal distance of the sprayer nozzles 105 and second airflow means 125 with respect to the main central body 150 and / or adjust their vertical position with respect to the main central body 150. The adjustable means 115 may therefore be configured to optionally adjust the horizontal distance of the sprayer nozzles 105 and second airflow means 125 either parallel or perpendicular to the direction of travel of the main central body 150 when in use. The adjustable means 115 are optionally controlled either manually or are controlled automatically using at least one sensor and control system which will be discussed when describing Figure 3. The sprayer nozzles 105 are configured so that, when the main central body 150 or adjustable means 115 are moving, they are fixedly held on the spray boom 110B with a second airflow means 125 surrounding at least part of the sprayer nozzle 105. The sprayer nozzles 105 are configured to receive, on their proximal side, liquid pesticide, airflow, and electrical energy from the main central body 150 by way of the flexible piping 130. On their distal side, the sprayer nozzles 105 are configured to project liquid pesticide spray horizontally, away from the main central body 150 and bank 110, towards a target canopy. The second airflow means 125 are configured to, on their proximal side, receive electrical energy from the main central body 150 and suck air into their housing using entrainment, and on their distal end are configured to produce a stream of air about the sprayer nozzles 105. In use, the main central body 150 moves along the ground drawn by any vehicle, for example a tractor, attached to the main central body 150 by a hooking or hitching mechanism, and provides liquid pesticide and airflow to the sprayer nozzles 105. The skilled person will, however, understand that the main central body 150 could also be powered and driven by its own means. The adjustable means 115 optionally moves the sprayer nozzles 105 and second airflow means 125 to be in line with target canopy and the sprayer nozzles 105 and second airflow means 125 in turn directs and projects individual liquid pesticide spraying cones outwards from the main central body 150 towards the target canopy as the main central body 150 is moving in use. Figure 1 shows an example pesticide sprayer 100. Figure 2 shows another example pesticide sprayer 200 with the same components as pesticide sprayer 100 but with a common second airflow means 225 on each bank 110 rather than individual second airflow means 125. As with Figure 1, the pesticide sprayer 200 is comprised of a main central body 150 and two banks 110 comprising sprayer nozzles 105. However, in Figure 2, the sprayer nozzles 105 of each bank 110 have one common second airflow means 225 for the bank 110 of sprayer nozzles 105 which are coupled to each sprayer nozzle 105 by way of aerodynamic fins. The common second airflow means 225 of each bank 110 is aligned with the ground in use, is shaped like an elliptical cylinder or rectangle, is hollow and surrounds at least part of each sprayer nozzle 105 on the bank 110. The common second airflow means 125 is configured to direct liquid pesticide spray towards the canopy. The spray produced by the bank 110 of pesticide sprayer 200 is the combined product of each individual spray cone produced by each sprayer nozzle 105. Figure 1, in comparison, has multiple spray cones produced by each sprayer nozzle 105 on the banks 110. In use, the example pesticide sprayer 200 of Figure 2 moves and projects liquid pesticide spray by way of a liquid pesticide spraying cone. The speed and / or power of the first and / or second airflow means 120, 125 and the size and / or volume of the liquid pesticide droplets may be controlled to control the geometry of the spray cone produced by a sprayer nozzle 105. The droplet size may be controlled based on the desired cone dimensions and therefore may influence the chosen speed of the rotary atomiser and the rate of flow of liquid pesticide supplied to the sprayer nozzle 105. The cone dimensions, for example wide or narrow, can be adjusted to suit the user’s specific spraying needs. A wider spraying cone is appropriate for target canopy of large surface area, and a narrow spray cone is more precise and appropriate for target canopy with less growth. Figure 3 shows a close-up view of one bank 110 of an example pesticide sprayer 300 and the main central body 150 of an example pesticide sprayer such as 100 and 200 in Figures 1 and 2. Figure 3 shows an example pesticide sprayer 300 comprising all the features as seen in Figure 1 as well as at least one sensor 305 and a control system 310. The at least one sensor 305 of each bank 110 is coupled to at least one of the second airflow means 125, at least one of the sprayer nozzles 105, and / or anywhere on the main central body 150, and the control system 310 is optionally coupled to the main central body 150. Connections between the at least one sensor 305 and control system 310 may be made physically through wiring which couples directly from the at least one sensor 305 to the control system 310 by way of the flexible piping 130 or optionally through a secondary network of flexible piping not shown in Figures 1, 2, or 3. The connections may also be made wirelessly, for example, via Bluetooth® or another short-range telecommunications network. The at least one sensor 305 may be positioned at any point along the second airflow means 125, sprayer nozzles 105, and / or the main central body 150. In Figure 3, sensors 305 are shown to couple to the underside of each second airflow means 125 near its proximal end and the control system 310 is shown to sit on the face of the main central body 150. However, the skilled person will understand that other positions of the at least one sensor 305 and control system 310 on the sprayer nozzle 105, second airflow means 125, or main central body 150 are appropriate and possible. The at least one sensor 305 is configured to detect the presence and absence and, optionally, the density of target vegetation in front of the sensor 305 and turn this information into data. The at least one sensor 305 transfers the detected data to the control system 310 by way of wires in the flexible piping 130 or wirelessly, for example, via Bluetooth® or another short-range telecommunications network. The control system 310 is configured to adjust each control valve’s 140 restriction on the liquid pesticide pathway, the liquid flow rate, each adjustable means’ 115 length, each atomiser 430 motor speed, and the airflow means’ 120, 125 speeds individually. In use, the at least one sensor 305 detects the presence and location of and, optionally, the density of target canopy in front of the distal end of at least one sprayer nozzle 105, convert this information into data and inform the control system 310 of the canopy conditions. The control system 310 understands the information and instructs the adjustable means 115, pump 145, firstairflow means 120, second airflow means 125, and control valves 140 to speed up or slowdown in response to the received data. As a result, in use, the changing target canopy is efficiently covered with a consistent amount of liquid pesticide spray while the pesticide sprayer 300 is moving. Further details about the architecture of the control system 310 and at least one sensor 305 are discussed with reference to Figure 12. Figure 4A, 4B, and 4C show a close-up perspective view, a deconstructed view, and a side on view of one of the sprayer nozzles 105 as depicted in Figures 1 to 3. The sprayer nozzle 105 comprises a nozzle housing 405 and atomiser 430, wherein the atomiser 430 is located partially inside the nozzle housing 405. The sprayer nozzle 105, nozzle housing 405, and atomiser 430 will be described in greater depth in Figures 6 to 12. The nozzle housing 405 has a longitudinal axis X and is located on the bank 110 such that the longitudinal axis X is aligned generally parallel with the ground when the pesticide sprayer is in use and points axially away from the main central body 150. The nozzle housing 405 has a proximal end 405P proximal to the main central body 150, which couples to the flexible piping 130 of Figures 1, 2, and 3, and a distal end 405D which is distal to the main central body 150 and is open ended to the atmosphere. The sprayer nozzle 105 is made such that it optionally comprises components, namely the nozzle housing 405 and atomiser 430, which slot together to form the sprayer nozzle 105. The atomiser 430 partially or fully slots into the nozzle housing 405 on its distal side. The atomiser 430 comprises an atomiser motor case 420 and a rotary atomiser 425 wherein the rotary atomiser 425 sits adjacent to, on the distal side of, the atomiser motor case 420. The nozzle housing 405 comprises an airflow case 410 and a nozzle head 415 which slot together, wherein the airflow case 410 sits at the proximal side of the nozzle housing 405 and the nozzle head 415 sits at the distal side of the nozzle housing 405. As a result, the sprayer nozzle 105 is comprised of, in order of distance from the main central body 150 along the axis X, an airflow case 410, a nozzle head 415, an atomiser motor case 420, and a rotary atomiser 425. Each component is optionally annular in shape and gets smaller in radius and cross-sectional area with distance from the main central body 150. The airflow case 410 and nozzle head 415, described in greater detail in Figure 5, optionally comprise chambers, guide vanes, and aerodynamic fins. The rotary atomiser 425 and atomiser motor case 420, described in greater detail in Figure 8, optionally comprise atomiser teeth, guide vanes, a motor, and a filament generator. The atomiser 430 slots into the nozzle head 415 and airflow case 410. The airflow case 410 and nozzle head 415 are optionally reversibly coupled to one another by way of at least one clip and are reversibly attached to one another to form the sprayer nozzle 105. The clips are not shown in Figure 7. The skilled person will understand that any variation of clipping mechanism may be used to hold these components together. The clipping mechanism may be seen in greater detail in Figure 9A. The airflow case 410 and nozzle head 415 are configured to provide a pathway for the liquid pesticide and airflow from the flexible piping 130 on the nozzle housing proximal end 405P to the nozzle housing distal end 405D and keep the two pathways separate throughout the nozzle housing 405. The nozzle housing 405, made up of the airflow case 410 and nozzle head 415, is also configured to house a motor, via the atomiser motor case, and at least a part of the atomiser 430. The atomiser motor case 420 is configured to house a motor and the rotary atomiser 425 is configured to receive the liquid pesticide from a liquid inlet pipe within the nozzle housing 405, via the atomiser motor case 420. The liquid pipe is spoken about in greater detail with reference to Figures 5 and 8. The airflow case 410 is configured to make the airflow diverge, when moving from its proximal end to its distal end, and the nozzle head 415 is configured to make the airflow converge, when moving from its proximal end to its distal end. The nozzle housing 405 is therefore configured to direct airflow away from the nozzle central axis X and back again to focus the airflow about the lip of the atomiser 430. Motion of the airflow is described in better detail with reference to Figures 5, 6, 7, and 11. The rotary atomiser 425 is also configured to be turned by the motor, which it is coupled to, and in turn break up the liquid pesticide into droplets beyond the nozzle housing. Further details of the motor are described when referencing Figure 8. In use, the airflow case 410 and nozzle head 415 direct airflow and liquid pesticide from the flexible piping 130 to be converged at the lip of the atomiser 430. The atomiser motor case 420 allows the motor inside the sprayer nozzle 105 to operate, turning the rotary atomiser 425, without obstructing or diverting the liquid pesticide or airflow pathways. In use with a motor, the rotary atomiser 425 receives liquid pesticide from the liquid pesticide supply and produces liquid droplets on the lip of the atomiser, beyond the nozzle housing distal end 405D, which are moving tangentially to the rotary atomiser’s 425 axis of rotation. These liquid droplets are entrained by the airflow exiting the nozzle head 415. The optional clipping mechanisms, in use, hold the sprayer nozzle 105 together. When not in use each reversibly attachable part (rotary atomiser 425, atomiser motor case 420, nozzle head 415, and airflow case 410) of the sprayer nozzle 105 can optionally be taken apart by the clipping mechanisms for easy maintenance, replacement, orcleaning and reattached later. by showing its cross-section. As previously stated, the sprayer nozzle 105 comprises a nozzle housing 405, an atomiser 430, and a motor 505, which is coupled to the atomiser 430. As stated previously, the nozzle housing 405 is comprised of an airflow casing 410 and nozzle head 415 and has a proximal end 405P proximal to the main central body 150, which couples to the flexible piping 130, and a distal end 405D which is distal to the main central body 150 and is open ended to the atmosphere. The atomiser 430 is comprised of the atomiser motor case 420 and rotary atomiser 425. The nozzle housing 405 is arranged to completely contain the atomiser motor case 420 and part of the rotary atomiser 425 in its vicinity. The atomiser 430 has the atomiser motor case 420 on its proximal end, which houses the motor 505 and is within the vicinity of the nozzle housing 405. The distal end of the atomiser 430, distal to the main central body 150 and bank 110, protrudes beyond the nozzle housing 405 forming an atomiser lip. In some embodiments, the entirety of the atomiser 430 is proud of the nozzle housing 405 and in others it is entirely within the nozzle housing 405 with no lip. The atomiser 430 and motor 505 sit on the axis X. The proximal end of the motor 505, couples to the liquid pesticide pathway 525 and allows it to pass through its centre along axis X. The liquid pesticide pathway 525, which sits on the axis X, is formed by a cylindrical structure, preferably a pipe or tube, within the airflow casing 410. At its distal end the liquid pesticide pathway 525 couples to the atomiser 430 and at its proximal end it couples to the flexible piping 130. The central structure of the nozzle housing, namely the atomiser 430, the housed motor 505, and the liquid pesticide pathway 525, is surrounded, but separated from, the airflow pathway 520. The airflow pathway 520 is formed by the outer chamber of the airflow case 410 and nozzle head 415. The airflow pathway 520 is optionally annular in shape, extends from the nozzle housing proximal end 405P to the nozzle housing distal end 405D, and surrounds the rotary atomiser 425, atomiser motor case 420, motor 505, and liquid pesticide pathway 525. The proximal end of the airflow pathway 520 is coupled to the flexible piping 130 and the distal end of the airflow pathway 520 is open to the atmosphere. The proximal end of the airflow pathway 520, within the airflow case 410 and coupled to the flexible piping 130, defines an airflow reduction portion. The airflow reduction portion is optionally an annular shaped chamber surrounding the liquid pesticide pathway 525 with a first width at its proximal end and a second width at its distal end, wherein the first width is greater than the second width. The middle of the airflow pathway 520 defines a divergent portion which sits at the distal end of the reduction portion and is optionally an annular chamber within the airflow case 410 that surrounds the liquid pesticide pathway 525. The divergent portion optionally has a first width at its proximal end and a second width at its distal end, wherein the first width is larger than the second width. The inner edge of the divergent portion chamber also optionally has a first distance from the axis X at its proximal end and a second distance from the axis X at its distal end, wherein the first distance is smaller than the second distance. The divergent portion, on its distal end, connects to a convergent portion, within the nozzle head 415. The convergent portion of the airflow pathway 520 is optionally an annular shaped chamber within the nozzle head 415 that surrounds the atomiser. The convergent portion is optionally constant in width and has an inner edge which, at its proximal end, sits a first distance from the axis X and, at its distal end, sits a second distance from the axis X, wherein the first distance is greater than the second distance. The distal end of the convergent portion opens to the atmosphere around the lip of the atomiser 430. The airflow pathway 520 optionally comprises additional features which are not shown in Figure 5. These optional additional features include, but are not limited to, aerodynamic fins, flow straighteners, and airflow guide vanes. Further details about the pathways are also described with reference to Figure 6. The atomiser motor case 420 is located at the distal side of the liquid pesticide pathway 525 and is coupled to the liquid pesticide pathway 525 and nozzle head 415. The atomiser motor case 420 comprises a central motor liquid pipe, discussed in Figure 8, which passes through its centre and couples to the liquid pesticide pathway 525 on its proximal end and the rotary atomiser on its distal end. The rotary atomiser 425, partially inside the nozzle head 415, optionally comprises optional atomiser guide vanes 515 and a filament generator at its proximal end, adjacent to the atomiser motor case 420. The rotary atomiser 420 also optionally comprises atomiser teeth 510 at its distal end, situated beyond the nozzle housing distal end 405D. Details of the rotary atomiser 425 will be discussed in more detail when referencing Figure 8. The sprayer nozzle 105 is configured to house a liquid pesticide pathway 525 and airflow pathway 520 adjacent but separate to one another. The sprayer nozzle 105 has multiple constituent parts, namely the atomiser 430, nozzle head 415, and airflow case 410, which are configured to direct the liquid pesticide through the motor housing case 420 into a rotary atomiser 425 and to direct the airflow from the flexible piping 130, around the atomiser 430, to converge about the distal end of the rotary atomiser 425. The atomiser motor case 420 is configured to hold a motor 505 which provides the rotary atomiser 425 with rotational motion for breaking up the liquid pesticide into droplets on the rotary atomiser 425 distal end. The atomiser motor case 420 is also configured so that it does not obstruct the liquid pesticide flow. In use, the flexible piping 130, liquid pesticide pathway 525, motor 505, and atomiser 430 accordingly provide the sprayer nozzle 105 with liquid pesticide, rotate the rotary atomiser 425 and break up the liquid pesticide into droplets of liquid pesticide which are ejected from the lip of the atomiser 430 distal end. The flexible piping 130 and airflow pathway 520 provide an airstream to the distal end of the rotary atomiser 425 and entrain liquid pesticide droplets in the airflow which in turn produces a liquid pesticide spray cone 530 beyond the distal end of the sprayer nozzle 105. The liquid pesticide spray cone 530 projects outwards from the distal end of the sprayer nozzle 105 along the axis X. Figure 6 shows the cross-section of the sprayer nozzle 105 in Figure 5 in greater detail with additional airflow pathway 520 components. The sprayer nozzle 105, along its airflow pathway 520, optionally comprises airflow guide vanes 605, aerodynamic fins 610, flow straighteners 615, and airflow reductors 620. The airflow reductors 620, which form the aforementioned airflow reduction portion, are located at the proximal end of the airflow pathway 520 and comprise part of the airflow case. The airflow reductors 620 taper the width of the airflow case 410 from its proximal end, where it couples to the flexible piping 130, towards its distal end, where it couples to the nozzle head 415. The size and shape of the airflow reductor 620 may vary depending on the sprayer nozzle 105 size. The aerodynamic fins 610 are thin and optionally comprise a length along the axis X, aligning them with the airflow direction. The aerodynamic fins 610 are optionally located at various points along the airflow pathway 520 and couple the liquid pesticide pipe 525 to the outer airflow casing 410. The flow straighteners 615 are also thin and optionally comprise a length along the axis X, aligning them with the airflow direction. The flow straighteners 615 are optionally located at the proximal end of the airflow pathway 520, within the airflow reduction portion, and are optionally positioned equidistantly along the circumference of the chamber which holds the airflow pathway 520. The airflow guide vanes 605 are also thin with a length along the nozzle axis X but, unlike the flow straighteners 615 and aerodynamic fins 610, are tilted with respect to the airflow direction. In examples, the tilt of the airflow guide vanes is between 10 and 20 degrees, more preferably the tilt of the airflow guide vanes is 15 degrees. The airflow guide vanes 605 are located within the distal end of the airflow pathway 520, about the atomiser 430. The air guide vanes are positioned equidistantly about the circumference of the airflow pathway 520 chamber. The airflow reductors 620 are configured to reduce the width of airflow received from the flexible piping 130 and focus the airflow into the divergent portion of the airflow case 410. The aerodynamic fins 610 are configured to hold the pipe housing the liquid pesticide pathway 525 and the atomiser 430 fixed at the centre of the nozzle housing 405 on the axis X, partially inside the airflow pathway 520 chamber. The flow straighteners 615 are also configured to provide additional strength for the internal features of the nozzle housing 405 as well as to reduce turbulent airflow within the airflow pathway 520 chamber and straighten the airflow to be directed from the proximal end of the sprayer nozzle 105 to the distal end of the sprayer nozzle 105. The airflow guide vanes 605 are configured to twist the airflow as it leaves the airflow pathway 520 so that it swirls about the rotary atomiser 425 lip beyond the nozzle housing distal end 405D. In use, the airflow reductors 620 and airflow straighteners 615 make the airflow laminar and narrow for entering the divergent and convergent portions of the airflow case 410. The aerodynamic fins 610 hold the atomiser 430 and liquid pesticide pathway 525 in a fixed position while reinforcing the laminarity of airflow in the airflow pathway 420. The airflow guide vanes 605, in use, cause the airflow to swirl about the ejected liquid droplets on the distal end of the atomiser 430, picking-up and entraining the slow-moving droplets up in their motion. The droplets are carried within the airflow creating a liquid pesticide spray cone 530. Driven by the airflow momentum, the liquid pesticide spray cone 530 is directed towards and deposited on target canopy positioned on the axis X on the distal side of the sprayer nozzle 105. Figure 7 shows a simplified cross-section of the sprayer nozzle in Figures 5 and 6. Figure 7 shows the flow reduction 705, divergent 710 and convergent 715 portions of the nozzle housing 405. The flow reduction 705, divergent 710 and convergent 715 portions of the nozzle housing 405 are all annular shaped chambers surrounding the liquid pesticide pathway 525, motor 505, atomiser motor housing 420, and / or part of the rotary atomiser 415. As previously stated, when discussing Figure 5, the flow reduction portion 705 tapers in width and cross-sectional area, in turn tapering the width and cross-sectional area of the nozzle housing 405 and airflow pathway 520, from its proximal end, coupled to the flexible piping 130, to its distal end, coupled to the divergent portion 710. The flow reduction portion comprises a first width at its proximal end and a second width at its distal end, wherein the first width is larger than the second width. The outer edge of the flow reduction portion is parallel to the axis X. The divergent portion 710 tapers in width and cross-sectional area from its proximal end, coupled to the flow reduction portion 705, to its distal end, coupled to the convergent portion 715. The divergent portion 710 also comprises one outer straight edge, parallel to the axis X, and an inner angled edge which has a first distance from the axis X at its proximal end and a second distance from the axis X at its distal end, wherein the first distance is smaller than the second distance. The divergent portion, therefore, angles the airflow pathway away from the axis X from its proximal end to its distal end and has a wider width on its proximal end compared to its width on its distal end. The convergent portion 715 sits at the distal end of the nozzle housing 405 and divergent portion 710 and surrounds the atomiser motor case 420 and part of the rotary atomiser 425. The convergent portion 715 has a constant width and an inner edge which tracks the outline of the atomiser 430. The convergent portion 715 outer edge is angled with respect to the axis X such that its proximal end sits a first distance from the axis X and its distal end sits a second distance from the axis X, wherein the first distance is larger than the second. The convergent portion 715 is open to the atmosphere and adjacent to the lip of the rotary atomiser 425 at its distal end. In some examples, the change in diameter of the nozzle housing 405 from the proximal end to the distal end is 10 to 12 mm, more preferably the nozzle housing proximal end 405P is 66 mm in diameter and the nozzle housing distal end 405D is 56 mm in diameter. The flow reduction portion 705 of the nozzle housing 405 is configured to narrow and focus airflow received from the flexible piping 130 into the divergent portion 710. The divergent portion 710 is configured to narrow the airflow received from the flow reduction portion 705 and forcibly push it outwards, increasing the airflow speed and reducing its static density by the Venturi effect. The convergent portion 715 is configured to redirect the sped-up airflow, while maintaining its speed, from the divergent portion 710 towards the lip of the rotary atomiser 425. Figure 7 depicts, by arrows, the change in density and speed of airflow in the different portions of the airflow pathway. The density of the arrow lines demonstrates the density of the airflow, and the length of the arrows demonstrates the airflow speed; shorter arrows are moving faster than longer arrows. In use, the flow reduction 705, divergent 710, and convergent portions 715 of the nozzle housing 405 narrow airflow received from the flexible piping 130, increase its speed and focus it about the lip of the rotary atomiser 425 at the nozzle housing distal end 405D. Figure 8 shows a close-up cross-sectional view of the distal end of an example sprayer nozzle 105 shown in Figures 4 to 7. The distal end of the sprayer nozzle 105 comprises a rotary atomiser 425, an atomiser motor case 420 housing a motor 505, and a motor liquid pipe 810. The sprayer nozzle 105 also optionally comprises a filament generator 805, liquid pesticide guide vanes 515, atomiser teeth 510, and airflow pathway guide vanes 605. The lip of the rotary atomiser 425, protruding beyond the nozzle housing distal end 405D, is also shown in Figure 8. The rotary atomiser 525 sits on the axis X and is coupled to the atomiser motor case 420 on its proximal side by the motor liquid pipe 810. The rotary atomiser 425, atomiser motor case 420, and motor liquid pipe 810 coupling is connected to the nozzle housing 405, along the nozzle axis X, by way of the optional aerodynamic fins 610 which cut transversely across the airflow pathway 520. The rotary atomiser 425 optionally comprises atomiser teeth 510, liquid pesticide guide vanes 515, a filament generator 805, and a solid cylindrical wall. The liquid pesticide guide vanes 515 and filament generator 805 are contained within and located on the proximal side of the rotary atomiser 425, adjacent to the distal end of the atomiser motor case 420 and motor liquid pipe 810. The atomiser teeth 510 are located within and on the distal end of the rotary atomiser 425. The space between the distal and proximal end of the rotary atomiser 425 is free space contained within the solid wall which holds the rotary atomiser 425 together. The motor liquid pipe 810 is located on the nozzle axis X and couples the rotary atomiser 425 to the motor 505, which is contained in the atomiser motor housing 420. The liquid pesticide guide vanes 515 are optionally arranged equidistantly around the filament generator 805 to form a circle of liquid pesticide guide vanes 515 with open space between each vane 515. In examples, the diameter of the atomiser is between 50 and 55 mm, more preferably the diameter is 52 mm. In examples, the atomiser may contain 39 atomiser guide vanes. The liquid pesticide guide vanes 515 support the filament generator 805 on the proximal side of the rotary atomiser 425 and are located such that they are at the distal end of the motor liquid pipe 810. The motor liquid pipe 810 passes through the atomiser motor housing 420 and motor 505 and connects to, and comprises the distal end of, the liquid pesticide pathway 525. The distal end of the rotary atomiser 425 comprises a ring of atomiser teeth 510 about an open centre. The atomiser teeth 425 are closely packed to one another with small separation between each tooth 425. The rotary atomiser 425 is configured such that its entire body is turned by the motor 505 in the atomiser motor housing 420 while receiving liquid pesticide through the motor liquid pipe 810 from the liquid pesticide pathway 520. The filament generator 805 is configured to redirect liquid pesticide from the motor liquid tube 810, shape it into a thin film of liquid pesticide which covers the proximal end of the rotary atomiser and pass the thin film into the surrounding atomiser guide vanes 515 as the atomiser rotates. The atomiser guide vanes 515 in the rotary atomiser 425 are configured to receive the thin film of liquid pesticide from the filament generator 805, allow the film to pass through its structure, and disintegrate the film of liquid pesticide into filaments or smaller strains of liquid as the rotary atomiser 425 is spinning. The liquid pesticide filaments are pushed outwards under the centrifugal force of the spinning rotary atomiser 425 to the atomiser teeth 510. The atomiser teeth 510 are configured to receive the filaments of liquid pesticide on their proximal side, trap them in its teeth 510, and disintegrate the filaments further into ligaments of liquid pesticide. The gaps between the atomiser teeth 510 are configured to allow droplets of liquid pesticide through to the distal side of the atomiser teeth 510. In examples, the droplets produced from the rotary atomiser 425 have a diameter between 80 and 250 pm. As previously mentioned, the airflow guide vanes 605 are configured to alter the pathway of the airflow leaving the distal end of the airflow pathway 520 so that it twists about the lip of the rotary atomiser 425. In use, the rotary atomiser 425 receives rotational motion and liquid pesticide from the motor 505 inside the atomiser motor housing 420 and the motor liquid pipe 810. The rotary atomiser 425 breaks the liquid pesticide into filaments, by way of the atomiser guide vanes 515, and then forces the filaments into the atomiser teeth 510, under the centrifugal force, which breaks the filaments into ligaments of liquid pesticide, and then droplets. The droplets pass through to the distal side of the rotary atomiser 425 where they are picked up and entrained by the airflow which is twisted about the lip of the rotary atomiser 425. The airflow carries the liquid pesticide droplets away from the rotary atomiser 425, along the axis X, in the form of a liquid pesticide spray cone 530 towards the target canopy. Figure 9A shows a front-on view of the distal end of a possible embodiment of a sprayer nozzle 105 of Figures 4 to 8. This figure shows the lateral arrangement of the nozzle head 415, airflow case 410, airflow guide vanes 605, and atomiser teeth 510 in greater detail. Figure 9B shows a front-on view of the proximal end of the sprayer nozzle 105 of Figures 4 to 8. This figure shows the inside of the airflow pathway 520 and shows the arrangement of the airflow straighteners 615, airflow case 410, aerodynamic fins 610, and airflow guide vanes 605 about the atomiser motor case 420. Figure 10 shows a front-on view of a possible embodiment of a coupling between a sprayer nozzle 105 and second airflow means 125 via aerodynamic fins 1005 as depicted in Figures 1 to 3. The coupling of the sprayer nozzle 105 to the second airflow means 125 via the aerodynamic fins 1005 comprises the sprayer nozzle 105, the second airflow means 125, the spray boom 110B, aerodynamic fins 1005, and flexible piping 130. As previously described, the second airflow means 125 is hollow, cylindrical, and surrounds at least part of the sprayer nozzle 105. In this figure the second airflow means 125 is coupled to the spray boom 110B at its side. However, the skilled person will understand that other coupling points for the spray boom 110B to the second airflow means 125 are appropriate and can be utilised. For example, the second airflow means 125 may be stacked on top of one another with a bank 110 attaching to either side of the second airflow means 125. The sprayer nozzle 105 is optionally held at the centre of the second airflow means 125 by way of two or more aerodynamic fins 1005. The aerodynamic fins 1005 are positioned either side of the sprayer nozzle 105; they are thin and have optional length along the nozzle axis X. The flexible piping 130 optionally couples to the proximal end of both the sprayer nozzle 105 and second airflow means 125. The first airflow means 120 and second airflow means 125 are configured to provide shaping air and carrier air which entrails liquid pesticide droplets from the distal end of the sprayer nozzle 105 to target canopy. The sprayer nozzle 105 is configured to provide the cross-sectional area and density of liquid pesticide spray, towards the target canopy of choice, and the second airflow means 125 or carrier air is configured to provide specific longitudinal momentum to the droplets to ensure they reach the target canopy of choice. The second airflow means 125 is also configured to counteract turbulent flow caused by ambient wind conditions about the nozzle housing distal end 405D. The aerodynamic fins 1005 optionally hold the sprayer nozzle 105 in place in the centre of the second airflow means 125 without obstructing the second airflow means 125 and the flexible piping 130 provides airflow and liquid pesticide to the sprayer nozzle 105, as well as optional electrical energy to the second airflow means 125 and motor 505. In use, the sprayer nozzle 105 and second airflow means 125 produce a strong and directional liquid pesticide spray cone 530 which covers target canopy. The flexible piping 130 optionally provides electrical energy to the second airflow means 120 and the motor 505 of the sprayer nozzle 105 and the bank 110 holds the sprayer nozzles 105 and second airflow means 125 in the optimal place to spray the target canopy. Figures 11A and 11B show a simplified cross-section of a sprayer nozzle 105 from Figures 4 to 7. These figures both show the nozzle housing 405, atomiser 430, airflow pathway 520, and liquid pesticide spray cone 530. In Figure 11A the sprayer nozzle 105 comprises a relatively strong airflow, depicted as the large arrows, within the airflow pathway 520. Figure 11A also shows a liquid pesticide spray cone 530 at the distal end of the sprayer nozzle 105, positioned beyond the nozzle housing distal end 405D. The liquid pesticide spray cone 530 is aligned with the axis X and is narrow at the sprayer nozzle 105 distal end and widens with distance along the axis X from the sprayer nozzle 105 distal end. Figure 11B, in comparison to Figure 11 A, shows a sprayer nozzle 105 comprising a relatively weak airflow, depicted by the small arrows, within the airflow pathway 520. The airflow is coupled to a liquid pesticide spray cone 530, positioned beyond the nozzle housing distal end 405D. This liquid pesticide spray cone 530 comprises liquid pesticide droplets entrained in the airflow. The spray zone 530 is aligned with the axis X, is narrow at the sprayer nozzle 105 distal end and widens with distance along the axis X from the sprayer nozzle 405 distal end. In comparison, Figure 11A comprises a spray cone 530 which reaches a greater distance from the distal end of the sprayer nozzle 105 compared to the spray cone 530 in Figure 11B. Moreover, the spray cone 530 in Figure 11A does not widen perpendicularly from the axis X as much as the spray cone 530 in Figure 11B. The geometry of the spray cone 530 may be controlled. The control system may be configured to determine the density of and distance to vegetation canopy based on sensor signals and control the speed and / or power of the first and / or the second airflow means 120, 125 based on the determined distance of the vegetation canopy to control the size of the droplets produced by the atomiser 430 and the distance and breadth of canopy reached by the spray cone 530, wherein increasing the speed and / or power of the first and / or second airflow means 120, 125 increases the force of the entrained droplets and creates a narrower spray cone 530 which projects liquid pesticide droplets a relatively long distance from the sprayer nozzle 105. Likewise, decreasing the speed and / or power of the first and / or second airflow means 120, 125 decreases the force of the travelling droplets and creates a wider spray cone 530 which projects liquid pesticide droplets a relatively short distance from the sprayer nozzle 105. The control system 310 may be configured to control the rotational speed of the rotary atomiser 425 based on the determined distance to the vegetation canopy and adjust the shape of the liquid pesticide cone 530 produced beyond the sprayer nozzle 105, wherein faster rotation creates a wider liquid pesticide cone 530. The control system 310 may be configured to control the liquid flow rate based on the determined distance to the vegetation canopy and adjust the droplet size produced beyond the sprayer nozzle 105, wherein a faster liquid flow rate produces larger droplets which travel a small axial distance, and a slower liquid flow rate produces smaller droplets which travel a great axial distance. The control system 310 may also be configured to control the rotational speed of the rotary atomiser 425 based on at least one parameter of the target canopy, for example, density, topology, and surface characteristics. The convergent portion 715 of the airflow pathway 520 is configured to focus the airflow from opposing sides of the airflow pathway 520 chamber about the central lip of the atomiser 430. In doing so, the airflow from the sprayer nozzle 105 comes together at a central point on the axis X before spreading out, entraining liquid pesticide droplets, with distance from the lip of the atomiser 430. Faster airflow speed has a greater axial velocity and a greater airflow pathway 520 convergence at the convergent portion 715 creating a narrower liquid pesticide spray cone 530 which covers a greater axial distance from the sprayer nozzle 105. Slower airflow speeds have a slower axial velocity and a reduced airflow pathway 520 convergence at the convergent portion 715 creating a wide liquid pesticide spray cone 530 which covers a greater tangential distance from the axis X. In use, the airflow supplied to the sprayer nozzles 105 is adjusted according to the at least one sensor 305 readings. The control system 310 provides instructions to the first airflow means 120, sprayer nozzles 105, and second airflow means 125 to adjust accordingly and produce either a long reaching and narrow spray cone 530 or a short reaching and wide spray cone 530 so that the target canopy is efficiently covered in liquid pesticide spray. The power required to power a sprayer nozzle 105 is in the range of 110 to 200W. The angle of diffusion of the liquid pesticide spray cone 530 from the atomiser 430 is also positively correlated with the power consumption of the sprayer nozzle 105. Figure 12 shows a possible embodiment of the at least one sensor 305 of the pesticide sprayer 300 and possible embodiment of the architecture of the control system 310 which it transfers data to. The control system 310 optionally comprises middleware, digital signals, SCL / SDAs, PWMs, servo drivers, high-speed controllers, feedback mechanisms, MOSFETs, stepper motor drivers, liquid flow meters, a wheel encoder, servo motors, BLDC motors, pump controls, and fan controls. This control system 310 also connects to the pesticide sprayer’s 300 valves 140, adjustable means 115, pump 125, first airflow means 120, motor 505, and second airflow means 125. The at least one sensor 305 is configured to communicate information to the SCL / SDA, PWM, stepper motor driver, and MOSFET by way of the middleware. Feedback mechanisms are also configured to calibrate the control system 310, such as the water flow meter and wheel encoder. The SCL / SDA, PWM, MOSFET, and stepper motor driver are configured to accordingly instruct the servo driver, high power speed controller, valves 140, and adjustable means 115 to adjust in response to the sensor signals. The servo driver is configured to further instruct the servo motor and BLDC motor to adapt to canopy undulations. The high-power speed controller is configured to instruct, via the pump control and fan controls, the pump 125, second airflow means 125, and first airflow means 120 to increase or decrease liquid and airflow production in response to canopy conditions. In use, the control system 310 recognises the canopy conditions in front of the sprayer nozzle 105, sends data to middleware which changes the data into instructions and communicates these instructions to variable components of the pesticide sprayer 300. The variable components, namely valves 140, adjustable means 115, the servo motors, the BLDC atomiser motors, the pump 125, the second airflow means 125, and the first airflow means 120, adjust their operation accordingly to efficiently produce liquid pesticide spray for the target canopy. Figure 13 shows a perspective view of a possible embodiment of the pesticide sprayer 100 as intended for use. This figure, due to its perspective view, does not show all the components of the pesticide sprayer 100 but does comprise the main central body 150, the first airflow means 120, the sprayer nozzles 105, the second airflow means 125, flexible piping 130, control valves 140, banks 110, the pump 145, the battery 125, sensors 305, and the control system 310. The skilled person will understand that this pesticide sprayer 100 is just one example of the arrangements of the pesticide sprayer components. For example, the sprayer nozzles 105 may also sit on a horizontal spray boom 110B and the control system 310 could also sit on the main central body 150. This pesticide sprayer 100 is configured to provide liquid pesticide spray to target canopy on either side of its main central body 150 while moving along a terrain in use. It will be appreciated from the discussion above that the embodiments shown in the figures are merely exemplary, and include features which may be generalised, removed, or replaced as described herein and as set out in the claims. In the context of the present disclosure other examples and variations of the apparatus and methods described herein will be apparent to a person of skill in the art. For example, the present disclosure describes embodiments for spraying liquid pesticide however it will be appreciated that other liquids may be suitable such as, but not limited to, plant treating liquids, bioactive compounds, fertiliser, herbicide, fungicide, water, growth regulators, adjuvants liquid nutrients, soil conditioner and combinations thereof.

Claims

1. A pesticide sprayer for coating vegetation with liquid droplets of pesticide comprising;a plurality of sprayer nozzles arranged as a bank of sprayer nozzles, each sprayer nozzle individually supplied with pesticide liquid from a common reservoir;a first airflow means for providing a stream of air to each sprayer nozzle; and a second airflow means for providing a stream of air around each sprayer nozzle.

2. The pesticide sprayer of claim 1 wherein the pesticide sprayer comprises two banks of sprayer nozzles, wherein each sprayer nozzle of each bank is provided with a respective second means for providing a stream of air to each corresponding sprayer nozzle.

3. The pesticide sprayer of claim 1 or 2 wherein the pesticide sprayer comprises two banks of sprayer nozzles, wherein each bank is provided with a common second means for providing a stream of air to the bank of sprayer nozzles.

4. The pesticide sprayer of claim 2 or 3 wherein each bank of sprayer nozzles is on an opposing side of the pesticide sprayer, and wherein the relative position of each sprayer nozzle on each bank is adjustable vertically, and wherein the relative position of each bank is adjustable horizontally.

5. The pesticide sprayer of any of claims 1 to 4 wherein the first airflow means comprises a common fan.6 The pesticide sprayer of any of claims 1 to 5 wherein the second airflow means comprises a bladeless fan.

7. The pesticide sprayer of any of the previous claims wherein each sprayer nozzle comprises a respective atomiser for breaking up the liquid into droplets.

8. The pesticide sprayer of claim 7 wherein each sprayer nozzle comprises a respective motor for driving the corresponding atomiser.

9. The pesticide sprayer of any of the previous claims wherein each sprayer nozzle comprises an airflow pathway and a liquid pesticide pathway, wherein the airflow pathway surrounds and is coaxial with the liquid pesticide pathway.

10. The pesticide sprayer of claim 9 as dependent on claim 7 or 8 wherein each sprayer nozzle has a proximal end and a distal end, wherein the liquid pesticide and airflow from the first airflow means enter the sprayer nozzle at the proximal end and exit via the distal end, wherein the atomiser is proximal to the distal end, and wherein the atomiser is adjacent to atomiser teeth which are configured to break the liquid pesticide into fine droplets at a distal part of the atomiser, beyond the nozzle, which can be easily moved by low air speeds.

11. The pesticide sprayer of claim 10 wherein the airflow pathway comprises a divergent portion proximate to the proximal end and a convergent portion proximate to the distal end, wherein the cross-sectional area of the airflow pathway reduces from the proximal end to the distal end in the divergent portion, and wherein the liquid pesticide pathway comprises a divergent portion proximate to the proximal end and a convergent portion proximate to the distal end.

12. A sprayer nozzle for coating vegetation with liquid droplets of pesticide, the sprayernozzle comprising:a nozzle housing having a proximal end and a distal end, wherein the housing is configured to receive liquid pesticide and airflow at the proximal end and exit via the distal end, wherein the housing is configured to provide (i) an airflow pathway and (ii) a liquid pesticide pathway;wherein the airflow pathway surrounds and is coaxial with the liquid pesticide pathway, and comprises a divergent portion proximate to the proximal end and a convergent portion proximate to the distal end, wherein the nozzle housing is configured to reduce the cross-sectional area of the airflow pathway from the proximal end to the distal end in the divergent portion; andwherein the liquid pesticide pathway comprises a divergent portion proximate to the proximal end and a convergent portion proximate to the distal end.

13. The pesticide sprayer of claim 12 wherein the airflow pathway comprises guidevanes at the distal end of the airflow pathway.

14. The pesticide sprayer of claim 12 or 13, further comprising a rotary atomiser proximal to the distal end of the nozzle housing and coupled to the liquid pesticide pathway.

15. The pesticide sprayer of claim 14 wherein the rotary atomiser is adjacent to atomiser teeth which are configured to break the liquid pesticide into fine droplets at a distal part of the atomiser, beyond the nozzle housing, which can be easily moved by low air speeds.

16. The pesticide sprayer of claim 15 wherein the convergent distal end of the airflow pathway is arranged to form a narrow axial spray of liquid pesticide beyond the nozzle housing.

17. A bank of sprayer nozzles comprising a plurality of the nozzles of any of claims 12 to 16, wherein the bank of sprayer nozzles are coupled to a common airflow means for supplying a stream of air to each of the nozzles of the bank of nozzles.

18. A sprayer nozzle for coating vegetation with liquid droplets of pesticide, the sprayer nozzle comprising;a nozzle housing having a proximal end and a distal end, wherein the housing is configured to receive liquid pesticide and airflow at the proximal end and exit via the distal end;wherein the housing houses a rotary atomiser proximal to the distal end of the housing and coupled to a liquid pesticide pathway, wherein the rotary atomiser is configured to break up liquid received via the liquid pesticide pathway into droplets; andwherein at least a portion of the rotary atomiser is arranged to sit proud of the nozzle housing which houses the atomiser.

19. The sprayer nozzle of claim 18 wherein the nozzle housing is arranged to provide an airflow pathway around the rotary atomiser within the nozzle housing.

20. The sprayer nozzle of claim 19 wherein the airflow pathway comprises a divergent portion proximate to the proximal end and a convergent portion proximate to the distal end,wherein the nozzle housing is configured to reduce the cross-sectional area of the airflow pathway from the proximal end to the distal end in the divergent portion21. A sprayer nozzle for coating vegetation with liquid droplets of pesticide, the sprayer nozzle comprising;a nozzle housing having a proximal end and a distal end, wherein the housing is configured to receive liquid pesticide and airflow at the proximal end and exit via the distal end;wherein the airflow pathway passes through the nozzle housing, surrounds and is coaxial with the liquid pesticide pathway, and comprises a divergent portion proximate to the proximal end and a convergent portion proximate to the distal end; anda control system configured to control the speed of airflow and adjust the convergence of the convergent portion.

22. The sprayer nozzle of claim 21 wherein the control system is configured to adjust the angle and distance of projection of liquid pesticide from the distal end of the nozzle housing.

23. The sprayer nozzle of claim 22 wherein the nozzle housing comprises an atomiser proximal to the distal end of the housing coupled to the liquid pesticide pathway configured to break the liquid into droplets at the distal edge of the sprayer nozzle.

24. The sprayer nozzle of claim 21 to 23 wherein the nozzle housing is configured to reduce the cross-sectional area of the airflow pathway from the proximal end to the distal end in the divergent portion, to converge the airflow pathway around the atomiser, wherein the airflow is configured to pick up the droplets in its flow.

25. The sprayer nozzle of claims 21 to 24 wherein a pump is configured to provide a variable supply of liquid pesticide and the control system is configured to provide a spray cone of liquid pesticide in the axial direction of the nozzle with a varying width tangential to the axial direction and depth along the axial direction.

26. The sprayer nozzle of claim 25 wherein the airflow is provided by a communal fan and flexible air ducts.

27. A pesticide sprayer for coating vegetation with liquid droplets of pesticide comprising;a plurality of sprayer nozzles, each sprayer nozzle individually supplied with pesticide liquid from a common reservoir;a first airflow means for providing a stream of air to each sprayer nozzle;a second airflow means for providing a stream of air around each sprayer nozzle;at least one sensor arranged to provide sensor signals indicative of vegetation canopy; anda control system configured to:determine the presence and distance of vegetation canopy based on the sensor signals; andadjust the rate of flow of the second airflow based on the determined presence and distance of the vegetation canopy.

28. The pesticide sprayer of claim 27 wherein the control system is configured to adjust the rate of flow of the second airflow means based on the determined presence and distance of the vegetation canopy to adjust liquid coverage across the vegetation canopy.

29. The pesticide sprayer of claim 27 or 28 wherein the control system is configured to adjust the rate of flow of the second airflow means based on the surrounding weather conditions to maintain a desired liquid pesticide spray coating on the target vegetation canopy.

30. The pesticide sprayer of any of claims 27 to 29 wherein the second airflow means comprises a bladeless fan configured to provide a flow of air around each sprayer nozzle.

31. The pesticide sprayer of any of claims 27 to 30 wherein each sprayer nozzle comprises a respective atomiser for breaking up the liquid into droplets and wherein the first airflow means is configured to pick up and axially direct the droplets towards the canopy and the second airflow means is configured to project the droplets the distance to the canopy.comprising;a plurality of sprayer nozzles arranged as a bank of sprayer nozzles, each sprayer nozzle individually supplied with pesticide liquid from a common reservoir;at least one sensor arranged to provide sensor signals indicative of vegetation canopy; anda control system configured to:determine the presence and distance of vegetation canopy based on the sensor signals; andadjust the position of the bank of sprayer nozzles based on the determined presence and distance of the vegetation canopy.

33. The pesticide sprayer of claim 32 wherein the control system is configured to adjust the position of the bank of sprayer nozzles based on the determined presence and distance of the vegetation canopy to maintain a constant distance between the bank of sprayer nozzles and the vegetation canopy.

34. The pesticide sprayer of claim 32 or 33 wherein the control system is configured to adjust the relative position of each sprayer nozzle of the bank of sprayer nozzles based on the determined presence and distance of the vegetation canopy.

35. The pesticide sprayer of any of the previous claims wherein (i) the relative position of each sprayer nozzle of the bank is adjustable vertically by way of adjustable means and / or (ii) the relative position of each bank is adjustable horizontally by way of adjustable means.

36. The pesticide sprayer of any of the previous claims, wherein the control system is configured to determine at least one parameter related to the atmosphere based on the sensor signals received from the at least one sensor, and to control the rate of liquid pesticide release of at least one of (i) the bank of the plurality of sprayer nozzles, or (ii) individual sprayer nozzles, based on at least one parameter related to the atmosphere.

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