WO2025087820A1

WO2025087820A1 - Pollen collection device and method

Info

Publication number: WO2025087820A1
Application number: PCT/EP2024/079605
Authority: WO
Inventors: Aleksandr PETRIAKOV
Original assignee: Syngenta Crop Protection AG Switzerland
Current assignee: Syngenta Crop Protection AG Switzerland
Priority date: 2023-10-27
Filing date: 2024-10-18
Publication date: 2025-05-01
Anticipated expiration: 2026-04-27

Abstract

Pollen collection device for collecting pollen from crop plants comprising an housing assembly and a collection hopper, the collection hopper being located beneath the housing assembly in order to define at least one lateral passageway between the housing assembly and the collection hopper to receive heads of crop plants, the pollen collection device comprising a fan provided at the top of the housing assembly in order to create an airflow in the lateral passageway in a radial and upward direction in order to force the pollen from the crop plants to enter the collection hopper through a lateral mesh wall of the collection hopper.

Description

POLLEN COLLECTION DEVICE AND METHOD

The present disclosure relates to a device and method for collecting pollen from crop plants, and more specifically to a device mountable on a motor driven vehicle for traveling along rows of crop plants to collect pollen from the plants and related methods. The invention provides an efficient solution to a critical step in plant reproduction, which interests corn seed producers but also other commodity crops producers who may apply the same solution for rice or wheat for example.

In the field of reproduction of plants, a plant is pollinated by transferring male gametes (pollen) to the female recipient members (stigmata) of a plant. This transfer may be affected by winds.

For some crops, natural pollination may prove impossible or more generally insufficient under natural conditions therefore leading to recourse to assisted artificial pollination. This assisted artificial pollination can take two forms:

- the exclusive artificial pollination process in which the only source of pollen is exogenous and applied by an artificial means to a plant having no natural source of pollen; for example, this is the case of single-sex dioecious species that must therefore receive exogenous pollen;

- the pollen supplementation process in which natural pollination is reinforced by adding pollen that may come from an exogenous source or from the pollinated plant itself.

Anemophile pollination plants belong to two very distinct groups: plants having "orthodox" pollen and plants having "recalcitrant" pollen. The terms "orthodox" and "recalcitrant" are derived from the names of seeds classed as a function of their tolerance to drying out and storability. Seeds are termed "orthodox" when they have good tolerance to drying out and good storability. In contrast, seeds for which drying out is lethal are termed "recalcitrant".

So-called "recalcitrant" pollen is intended for virtually immediate pollination because its viability is very short-lived and conditional upon maintaining a high level of hydration. This is the case of the pollen of wheat triticum sp.), barley (hordeum sp.), rice (oryza sp.) or maize (zea mays sp.). These pollens cannot be stored easily, are very fragile and require many precautions in handling them. Artificial pollination of plants having this kind of pollen involves specific technologies and practices respecting the very ephemeral viability of these pollens. The viability of the pollen corresponds to its reproduction potential.

There is known from the document FR. 2 866 784 Al an apparatus for collecting pollen from plants and for distributing it to the female members of other plants. It is known in the art that seed corn producers aim at finding the most efficient manner to pick up the pollen from the male plants and distribute the pollen gently, evenly and at the correct height on the female plants. For example, seed corn producers use apparatus which sucks the pollen upwardly from the male plants and then blows such pollen downwardly onto several rows of female plants located adjacent to the male plants, all at the same time.

But it is difficult to manage maturity of both male and female plants at the same time, and to mitigate the negative impacts of weather variability, there is a need to efficiently collect pollen and store it in the most efficient manner in order to allow for a later pollination. There therefore exists a need for enabling pollen to be preserved and stored and then applied at the optimal time to increase yield for corn seed producers.

Also, to improve pollen collection efficiency, there is a need for improving flowability of the pollen particles collected, such that the pollen still forms a powder able to readily flow. To that end, there is a need for a device providing high yield collection, together with an upper reliability and viability of the pollen collected. There is a need to overcome deficiencies of the prior art wherein pollen collection using methods that rely on suction and aspiration, pollen particles are driven to move at relatively large velocities; collision at such velocities can lead to particle clumping which, in turn, leads to a reduction in pollen 'reliability' and poor flowability.

To this end, the invention concerns a pollen collection device for collecting pollen from crop plants comprising an housing assembly and a collection hopper, the collection hopper being located beneath the housing assembly in order to define at least one lateral passageway between the housing assembly and the collection hopper to receive heads of crop plants, the pollen collection device comprising a fan provided at the top of the housing assembly in order to create an airflow in the lateral passageway in a radial and upward direction in order to force pollen from the crop plants to enter the collection hopper through a lateral mesh wall of the collection hopper.

Advantageously, the pollen collection device being motor driven along crop rows, heads of plants are not standing for a long time within the pollen collection device. In order to speed up the release of pollen by crop heads, the pollen collection device may comprise a shaking assembly attached to either one of the collection hopper or the housing assembly for shaking the crop plants in the passageway and mechanically displace pollen from the crop plants.

Another advantage for the pollen collection device being motor driven is that it may comprise a safety cover sheet and a support frame to be held by a frame connected to a motor driven vehicle, the support frame being raised atop the safety cover sheet. The safety cover sheet surrounds the housing assembly and comprises through-hole for allowing the airflow created by the fan to escape upward trough that through-hole at the top of the safety cover sheet. The safety cover sheet avoids undesirable particles to enter the fan.

Advantageously, the pollen collection device may comprise a removable storage jar removably connected at a bottom of the collection hopper to collect pollen entered into the collection hopper. The advantage of the storage jar being removable is that the pollen collection device may be operated during a long period of time, with the sole need of changing the storage jar whenever they are full, or that there is a need to place collected pollen under better preservation conditions than being connected to pollen collection device.

Preferably, to mitigate pollen path balanced by gravity and airflow within the passageway, the lateral mesh wall of the collection hopper forms an acute angle (alpha) with a vertical axis, such that the passageway defines a wider width in an upper portion of the lateral passageway than in a lower portion of such lateral passageway. Preferably, to operate two crop rows at a time, the pollen collection device comprises two lateral passageways on both sides of the collection hopper, such that pollen of two distinct rows of crop plants may be collected at the same time, collection hopper comprising two opposite lateral mesh walls such that pollen of the two distinct rows are mixed in the collection hopper. Airflows in both passageways tends to convey pollen in a central portion of the collection hopper, where pollen falls due to gravity.

For example, two opposite lateral mesh walls are connected at the top by a concave meshed wall located beneath the fan. Meshed walls have low impact on airflows but allows for a better selection of the pollen collected, as lateral mesh allow entrance of any particles up to 120% of an average diameter of the pollen to be collected, whereas the concave meshed wall of the top avoids entrance of particle having a diameter of 80% of the average diameter of the pollen to be collected. Said differently, the concave meshed wall receives particles but avoid any gravitational entrance of particles, even of pollen particles, as they are mixed with impurities, and covered with a film of impurities which impacts their reliability. To that end, the pollen collected is having a higher percentage of reliability. For example, for a pollen average diameter of 80 pm, then an average diameter of the holes within the lateral meshed wall is about 1 mm, whereas an average diameter of the holes within the concave meshed wall is about 70 pm.

In order to improve the airflow all along the passageway, the device may comprise a electrically driven motor located above the housing assembly and several fans along a longitudinal axis of the pollen collection device, lateral passageway being parallel to that longitudinal axis, all fans being independently power driven by the motor.

Preferably, the lateral mesh wall is planar, and a bottom surface of the collection hopper defines several inverted truncated cone-shaped receptacles adjacent to one another, and located below each fan, each inverted truncated cone-shaped receptacle comprising a bottom aperture to be connected to a removable storage jar. Inverted truncated cone-shaped receptacles allows the pollen to slide in the jars. According to one alternative embodiment of the collection hopper, it may comprise adjacent cells along the longitudinal axis, the collection hopper being provide with an inner partition in between two adjacent inverted truncated cone- shaped receptacles.

Advantageously, in order to increase pollen collection, and pollen selection, the pollen collection device may comprise at least one additional collection receptacle, chosen among one of a preeminent collection receptacle defined at the entrance of the collection hopper, and or side pocket external to the collection hopper to collect pollen unable to cross the lateral mesh wall.

The aim of the invention is also to provide a method of collecting pollen from crop plants grown in rows, the method comprising the followings steps:

- displacing a pollen collection device along a row of crop plants, the pollen collection device being attached to a motor driven vehicle, such that heads of the crop plants, and at least panicles or tassels with pollen, enter a passageway of a housing assembly of that pollen collection device,

- shaking the crop plants when they are in the passageway

- creating an under-pressure vacuum in that passageway such that an airflow in a radial and upward direction is created from inside the passageway to a lateral wall of the collection hopper, such that the vacuum is selected to allow the pollen to drop down into the collection hopper through a lateral mesh wall of that collection hopper.

Preferably, according to the method of the invention, fan speed may be selected in connection with motor driven vehicle's speed and unitary average weight of pollen particles to be collected.

Other features and advantages of the invention will become apparent on reading the following description of preferred embodiments of the invention given by way of example and with reference to the appended drawings.

Figure 1 represents a perspective view of one embodiment of pollen collection device according to the invention.

Figure 2 represents a sectional view of the embodiment of Figure 1 with crop plants located inside the pollen collection device. Figure 3 represents a perspective view of the embodiment of Figure 1 without safety cover sheet, a collection hopper of the pollen collection device being without mesh walls.

Figure 4 represents a perspective view of the collection hopper of the pollen collection device according to Figure 3.

Figures 5a, 5b and 5c represents a sectional view of a collection hopper according to the invention.

Figure 6 represents a top view of the embodiment of Figure 1.

Figures 7a and 7b represent sectional longitudinal view, respectively from the top and from a lateral orthogonal view, of airflow vectors within the pollen collection device according to the embodiment of Figure 1, when the device is moved. Figures 7a and 7b are extract from mathematical simulations involving a coupling between the flow and particle dynamics taking into account turbulence, the forces experienced by the pollen particles including drag, lift, added mass, and gravity.

Figures 8a and 8b represent an alternative embodiment of the collection hopper of Figure 7a and 7b wherein the collection hopper comprises inner cells.

Figure 9 represents pollen flux inside a collection hopper according to Figure 8a and 8b when the device is moved along a row of crop plants.

Figure 10 represents a table of combined effects of the tractor speed and the fan speed when operating a pollen collection device according to the invention.

Figure 11 represents a sectional view of an alternative embodiment of the collection hopper of Figure 4.

A pollen collection device 10 as represented Figure 1 is configured for collecting pollen from crop plants. The device is placed above crop plants, preferably crop plants raised in rows, such that the pollen collection device may be displaced along the rows to be able to collect pollen successively from all plants of a row. The pollen collection device 10 may not be itself motor driven. But according to the embodiment represented, the pollen collection device comprises means 9 to be connected to a frame 11 hauled by a tractor (not shown). The pollen collection device 10 comprises a housing assembly 12 and a collection hopper 13. The device 10 also comprises a safety cover sheet 8 above the housing assembly 12. A support frame 9 to be connected to the frame 11 is upwardly oriented from a top portion of the cover sheet 8. The device 10 presents a longitudinal axis X, and both the housing assembly and the collection hopper extends along that longitudinal axis X. The housing assembly 12 comprises an enlarged opening with acute angle walls 16 connected to longitudinal walls 17. Longitudinal walls 17 extend parallel to the longitudinal axis X and covers both lateral walls 18 and top wall 19 of the collection hopper. The housing assembly 12 has an inverted U-shaped profile in sectional view. The collection hopper is located beneath the central portion of that U-shaped profile.

Usually, the device 10 is displaced along its longitudinal axis. The device 10 comprises an entrance E to a passageway inside the device 10 for at least the heads of the crop plants being inside such passageway when the device is displaced along the row. Passageway is determined to receive panicles or tassels with pollen in the most upper part of the passageway.

The device comprises guiding bars 14 angularly opened in order to guide panicles or tassels with pollen of the crop plants in the direction of the entrance E. As represented Figure 1, the device comprises two lateral passageways 20, both passageways being located respectively on both longitudinal sides of the collection hopper 13. Longitudinal passageways are delimited between the collection hopper 13 and the housing assembly 12. Thus, the collection hopper 13 is central. The collection hopper 13 is provided at the entrance E with V- shaped guiding bars 15 to guide panicles or tassels respectively into each passageway. Guiding bars 14 angularly opened and the V-shaped guiding bars 15 both helps to strive heads of crop plants into the two lateral respective passageways.

Passageway 20 is created between longitudinal walls 17 and lateral wall

18, such passageway extending from the entrance E up to an outlet O, the outlet 0 being longitudinally opposed to the entrance E. Both passageways 20 are straight and define a tunnel. Passageways 20 on both side of the collection hopper communicate at the top of the collection hopper.

Figure 2, two distinct crop plants are represented respectively in each passageway 20. Passageways 20 are high enough to allow the head H, especially panicles located in the head H of the crop plant P to be at between mid-height and top of an inner height in the passageway 20. Depending on the type of crops, but usually the panicles are located in the uppermost position of the plant, and thus it is then preferred to present such panicles in the upper part of the passageways.

Figures 2, 3 and 5a, shakers 21 are emerging internally in the passageways 20 from longitudinal walls 17. Shakers 21 are tangling bars operated by a motor 22 supported by the support frame 9. Shakers 21 are operated in order to displace laterally the heads H inside the passageways 20, and then obtain the pollen to escape from the head H.

Alternatively, as shown in Figures 5b and 5c, shakers are provided with a rotary shaking system. This rotary shaking system comprises at least one rotary shaking system per passageway, Figure 5b, or could also comprise at least two opposite rotary shaking systems per passageway, Figure 5c. A rotary shaking system is preferably electrically driven in a continuous rotating motion. The rotary shaking system comprises a central longitudinal shaft 40, and three parallel bars 41, angularly placed and standing at a same distance from said longitudinal shaft. Bars 41 are linked to the shaft at their extremities, not shown in the sectional views of Figures 5b and 5c.

Preferably the longitudinal shaft is external to the longitudinal walls 17. In such configuration, longitudinal walls are provided with a longitudinal slit at least in the upper portion of the longitudinal walls in order to allow passage of the rotating bars trough it. When the rotary shaking system is positioned on one side of the passageway, it is rotated so that bars when in the passageway move inside the passageway from a lower position in the direction of an upper position inside such a passageway.

Figure 5c, when a same passageway comprises two opposite rotary shaking systems, both opposite rotary shaking system run in opposite rotating sense, so that bars of each system always move from a lower position to an upper position inside the passageway. Preferably both opposite rotary shaking systems are synchronised to avoid presenting bars in front of each other at a same height inside the passageway. In order to avoid injuries to the stem of the crop plants, opposite bars are placed at 60° angle away of each other, and synchronized to remain never at a same height inside the passageway at a same moment.

A fan 23 is provided through a top wall 24 of the housing assembly 12 to create an airflow F in the lateral passageway 20 in a radial and upward direction to direct the pollen from the crop plants to enter the collection hopper. A trough hole 40 is provided through the safety cover sheet 8 above the fan to avoid turbulences in the airflow above the fan. The fan is an electrically driven fan (not shown). Several fans may be provided all along and above the top meshed wall 19. Respective fans may be regulated independently from each other.

Lateral walls 18 of the collection hopper is preferably a mesh wall. Mesh wall 18 forms an acute angle alpha with a vertical axis Z. Alpha angle is selected between 0 and 45 °. Preferably alpha angle is between 0 to 15°. Angle tends to provide a wider space in the upperpart of the passageways, but lateral walls 18 could also tend to restrict the lateral width in the upperpart of the passageways. The lower the width of the passageways is, the more of pollen is forced to enter the collection hopper.

To adapt configuration of a collection device according to the invention to several type of crop plants, it could also be encompassed to provide adjustable longitudinal walls 17 position. Longitudinal walls 17 could be then adjustably placed away from the longitudinal meshed wall 18 to ascertain width depending on the crop from which pollen is to be collected. Then the lateral passageway 20 would become adjustable in width, longitudinal walls 17 comprising means (not shown) to allow lateral adjustment of their position relative to the top wall 24.

Thus, the passageways 20 defines a larger lateral width close to the top, near a connection between the longitudinal wall 18 and the top wall 19 of the collection hopper than at the connection between those longitudinal mesh walls 18 and a plain bottom surface 26 of the collection hopper. The bottom surface

26 comprises an aperture 27 where a storage jar 28 is removably secured to collect all pollen that fall under gravity in the direction of that aperture. Aperture

27 and pollen jar 28 are emerging downwards from the housing assembly 12. Storage jars may collect a volume of up to IL. Storage jars may be easily replaced from the device, at any moment it is needed, for example every 10 to 15 or even 20 minutes, in order to maximise pollen viability of the pollen collected in the jars.

Mesh walls 18 are panels removably mounted on a fixing structure 29a, 29b, 29c, and 29d of the collection hopper 13. This allows for the replacement of the mesh walls 18, and changes in mesh size of the mesh walls 18. Mesh walls are sized to avoid a type of anthers and or big parts and or insects to be collected, and to be wide enough to collect pollen, but also to limit air turbulence into the collection hopper. For example, mesh size is provided with circular openings having an inner diameter about 1 to 2 mm for corn seeds. The mesh walls 18 act as a waste filter to collect pollen with less impurities as possible. The mesh walls remove bigger particles like plant parts and insects.

Top wall 19 may also be a mesh wall. Top wall 19 is a pollen filter to avoid pollen to exit from the top of the collector due to air fans aspiration. Particle size of the mesh wall of the top wall 19 may be distinct from that of the mesh lateral walls 18. Top wall 19 forms acute angle beta with a vertical axis Z such that the top wall 19 defines a concave wall atop the aperture 27. Beta angle is selected between 45 and 90°. Top wall 19 may either be a flat wall, at 0° like in Figure 5c, or a multiangle concave surface, like in Figure 5a, presenting a concave portion mainly in the centre of the top wall 19, just below air fans. A concave top wall 19 is even needed when alpha angle is positive and at least over 5°, as top wall surface needs to be balanced by the angle to remain sensibly within a same range of area independently from the position of the lateral meshed walls 18.

As shown on Figure 3, the device 10 comprises several storage jars 28 along the longitudinal axis Y. Respective storage jars 28 are located at the bottom of each of several inverted truncated cone-shaped receptacles adjacent to one another. Those inverted truncated cone-shaped receptacles are forming together the bottom surface 26. The bottom surface 26 may comprises a square inverted truncated pyramid shape section above and immediately adjacent to the inverted truncated cone-shaped receptacles connected to the jars 28.

In the example represented Figure 6, the device comprises four storage jars 28, four fans 23. Speed of the successive fans may be balanced to create a vacuum such that an airflow obliquely is radially oriented from the passageways in the direction of the central collection hopper. Alternatively, all fan speed are set on a same fan speed, or regulated independently for improving collection yield set up. As the collection hopper length is increased, the speed of the tractor may also be increased, as the residence time of particles through the collector is expected to be similar. An optimal fan suction speed is determined beyond which particles are being sucked in the fans, which is detrimental to the yield.

The device comprises a front V shaped plane diverter 30 at the entrance E. V-shaped guiding bars 15 are placed around that diverter 30. The diverter 30 is prominent from the front portion of the collection hopper. That diverter 30 helps to smoothly convey airflow vectors into passageways 20 due to tractor speed, Figure 7a.

Airflow vectors are longitudinal to the passageways 20 , but also tends to converge toward the collection hopper, mostly in a central region of that collection hopper according to the longitudinal axis X. Figures 7a and 7b, the collection hopper is a single collection zone, with an open design. The collection hopper comprises four adjacent inverted truncated cone-shaped receptacles forming the bottom surface 26, each receptacle being respectively connected to a jar 28, and each jar being located right under one of the four fans 23 of the device. .

When considered according to a section view of Figures 7a, and 7b, airflow vectors are exiting quite homogenously throughout each of the four fan 23. Fan speed is selected to be below sedimentation speed of the pollen, such that evenso airflow vectors exits the fan, pollen still fall under gravity into the storage jars 28. Several dead zones Cl with no airflow vectors are identified. It is observed that internally an oscillation occurs all along the longitudinal axis of the collection hopper. That oscillation, and dead zones impacts recovery of pollen.

According to Figures 7a and 7b, a balance is to be achieve between the fan speed (Ufan) and the tractor speed (Ut) of the pollen collection device. A spatially-varying fan speed with higher suction speed at the front fan, close to the entrance E, decreasing all the way to the back allows to create a stronger void and promote the particles motion towards the axis of the collector earlier than with a uniform fan speed.

Figure 10, optimum collection fan speed has been discovered to be between 2 to 4 m/s. And surprisingly, the increase in the tractor speed impedes yield achievement of the pollen collection, unless inner cells are provided inside the collection hopper. This phenomenon may be explained by getting higher airflow speed and more volume of air going through the passageways and the collection hopper. Under high tractor speed, it becomes more difficult for the fans to compensate the airflow of the inherent speed of the pollen particles. Tractor speeds shortens pollen's period inside the passageways. An heterogenous air vacuum quality is provided by the fans when there is an important oscillation zone below the fans.

The particles dynamics is driven by Newton's Second Law of Motion where the acceleration of the particles is influenced by the added mass, the drag force (Wen-Yu model), the lift force (Saffman-Mei model), the acceleration due to gravity, and the pressure gradient. The acceleration is also influenced by a stochastic dispersion force linearly related to the square root of the turbulent kinetic energy and oriented in a random direction to account for small-scale turbulent fluctuations.

Figures 8a, 8b and 9 an alternative embodiment of the collection hopper in the scope of the invention, comprises adjacent cells along the passageways 20. Cells are such that transversal walls 31 are provided to delimit the volume defined inside the collection hopper by the meshed walls 18, the top wall 19 and the bottom surface 26. Where the collection hopper 13 comprises four receptacles, there are three transversal walls 31 forming an inner partition of the collection hopper. Here, the number of cells equals the number of adjacent inverted truncated cone-shaped receptacles of the bottom surface. Between two adjacent cone shaped receptacles a plain transversal wall 31 is raised such that pollen may be collected in a jar only if that pollen enters the corresponding cell through a portion of the mesh wall 18 and from borders of that cone shaped receptacle. This embodiment allows to provide distinct mesh structures for each cell.

Contrary to Figure 7b, airflow vectors are promoting a convection flux into each cell, and dead zones of a size as Cl aren't identified on Figure 8b. Vortical patterns improve the flow and the pollen particle distribution within each storage jars.

Cells bring better stability of the airflow inside each cell and improve mitigation of tractor speed and fan speed. It has been discovered smaller vortex in each cell, and an improved pollen collection in each cell. Vortexes improve air stability in the cells. Cells act as small clusters, which allow a better air fan suction quality to guide the pollen particles. Yield is improved with a same tractor speed with cells compared to open design. Yield may remain slightly the same for tractor speed twice as fast as with open design.

Also compared to Figure 7a, wherein airflows were exiting vertical from the fan, in Figure 8a, airflow vectors exit from the fan into an oblique backward direction, such that pollen would tend to remain in the vicinity of collection hopper evenso the device is moved along a row of crop plants. This would improve pollen collection. Pollen is pushed and sucked at the same time the device is moved along the row, such that the pollen is forced to cross the mesh walls 18.

As pollen particles may be lost at the back as they pass through the collector without "responding" to the suction from the fans, to promote lateral flow to push the pollen inwards and minimise the number of particles reaching the back of the collector, fins are provided on the longitudinal walls 17 to promote the flow towards the collector and jars. Fins are vertical and obliquely oriented toward the rear end of the collection hopper and the output 0.

According to Figure 9, the alternative embodiment of the collection hopper with inner cells also helps to restrict the quantity of pollen not trapped by the collection hopper. Pollen exiting from the output 0 without being trapped into the collection hopper is limited, and a specific higher air fan speed could be provided into the last cell of the collection hopper, the one close to that output without impacting airflow vectors in the vicinity of the other cells closer from the entrance E.

At a low tractor speed of 4km/h, an increase of nearly 20% at the peak efficiency is obtained with inner cells, which is obtained at a fan suction speed of 3m/s. The inner cell design is less sensitive to the fan suction speed. The inner cell design appears to be a good trade-off for increased efficiency with less sensitivity to the fan suction speed and the tractor speed while maintaining a high collection yield. The inner cell design reaches the same efficiency as the design without inner cells but with a tractor speed twice as high. Figure 11 an improved embodiment of the collection hopper 13 wherein a front collector 32 is provided below the V shaped guiding bars 15, as pollen may already be shaken by those V shaped bars, and the front collector 32 offers a V shaped entrance with a front collection jar 33 connected below thereto. The front collector 32 presents a V shaped aperture, and the diverter 30 is located partially over that aperture. According to this embodiment, pollen collected into the front collection jar is not filtered. This front collector forms a preeminent collection receptacle, wherein an aperture to connect the front collection jar is not centred in the middle of the shape of such front collector but located close from the entrance E to ease removal and replacement of such front jar 33. Additionally, collection hopper may advantageously be provided with lateral pockets 34, along the passageways 20, those pockets 34 collecting pollen into lateral jars connected thereto. Pollen collected into those lateral jars were not pushed through the mesh wall 18. This embodiment allows for an improved collection of pollen, and also a better selection among the pollen collected, as pollen collected into the front collection jar and lateral jars present a lower level of purity compared to the pollen collected into jars 28 connected to the inverted truncated cone-shaped receptacles where such pollen has been filtered by mesh lateral and top walls 18 and 19. Pollen collected may be treated and used for different purposes, while avoiding loss of pollen while collection.

Claims

REVENDICATIONS

1. A pollen collection device for collecting pollen from crop plants comprising an housing assembly (12) and a collection hopper (13), the collection hopper being located beneath the housing assembly in order to define at least one lateral passageway (20) between the housing assembly and the collection hopper to receive heads of crop plants, the pollen collection device comprising a fan (23) provided at the top of the housing assembly in order to create an airflow in the lateral passageway in a radial and upward direction in order to force pollen from the crop plants to enter the collection hopper through a lateral mesh wall (18) of the collection hopper.

2. A pollen collection device according to claim 1 wherein the pollen collection device comprises a shaking assembly (21) attached to either one of the collection hopper or the housing assembly for shaking the crop plants in the passageway and mechanically displace pollen from the crop plants.

3. A pollen collection device according to claim 2 wherein the shaking assembly comprises a rotary shaking system comprising a central longitudinal shaft and three equally angularly spaced bars, the central shaft being rotatable such that the bars are displaced inside the passageway from a bottom location to an upper location.

4. A pollen collection device according to claim 1 or 2 wherein the pollen collection device comprises a safety cover sheet (8) and a support frame (9) to be held by a frame (10) connected to a motor driven vehicle, the support frame being raised atop the safety cover sheet, such that the safety cover sheet surrounds the housing assembly allowing the airflow created by the fan to escape upward trough a through-hole (40) at the top of the safety cover sheet.

5. A pollen collection device according to any one of the preceding claims wherein the pollen collection device comprises a removable storage jar (28) removably connected at a bottom of the collection hopper in order to collect pollen entered into the collection hopper.

6. A pollen collection device according to any one of the preceding claims wherein the lateral mesh wall of the collection hopper forms an acute angle (alpha) with a vertical axis, such that the passageway defines a wider width in an upper portion of the lateral passageway than in a lower portion of such lateral passageway.

7. A pollen collection device according to any one of the preceding claims wherein the lateral passageway (20) is adjustable in width, longitudinal walls (17) of the housing assembly (12) comprising means to allow lateral adjustment of their position relative to the top wall (24).

8. A pollen collection device according to any one of the preceding claims wherein it comprises two lateral passageways on both sides of the collection hopper, such that pollen of two distinct rows of crop plants may be collected at the same time, collection hopper comprising two opposite lateral mesh walls such that pollen of the two distinct rows are mixed together in the collection hopper.

9. A pollen collection device according to the preceding claim wherein the two opposite lateral mesh walls are connected at the top by a top meshed wall (19) located beneath the fan, the top mesh wall acting as a pollen filter to avoid exit of the pollen entered in the collection hopper.

10. A pollen collection device according to any one of the preceding claims wherein it comprises an electrically driven motor located above the housing assembly and several fans along a longitudinal axis of the pollen collection device, lateral passageway being parallel to that longitudinal axis, all fans being independently power driven by the motor.

11. A pollen collection device according to the preceding claim wherein the lateral mesh wall is planar, and a bottom surface of the collection hopper defines several inverted truncated cone-shaped receptacles adjacent to one another, and located below each fan, each inverted truncated cone- shaped receptacle comprising a bottom aperture to be connected to a removable storage jar.

12. A pollen collection device according to the preceding claim wherein the collection hopper defines adjacent cells along the longitudinal axis, the collection hopper comprising an inner partition (31) in between two adjacent inverted truncated cone-shaped receptacles.

13. A pollen collection device according to any one of the preceding claims wherein it comprises an additional collection receptacle, chosen among one of a preeminent collection receptacle (32) defined at the entrance of the collection hopper, and or side pocket (34) external to the collection hopper to collect pollen unable to cross the lateral mesh wall.

14. Method of collecting pollen from crop plants grown in rows, the method comprising the followings steps:

- displacing a pollen collection device along a row of crop plants, the pollen collection device being attached to a motor driven vehicle, such that heads of the crop plants enter a passageway of an housing assembly of that pollen collection device,

- shaking the crop plants when they are in the passageway

- creating an under pressure vacuum in that passageway such that an airflow in a radial and upward direction is created from inside the passageway to a lateral wall of the collection hopper, such that the vacuum is selected to allow the pollen to drop down into the collection hopper through a lateral mesh wall of that collection hopper.

15. Method according to the preceding claim wherein the method comprises: selecting fan speed in connection with motor driven vehicle's speed and unitary average weight of pollen particles to be collected.