DE102021128300A1 - Process and device for applying plant protection products to plant parts - Google Patents

Abstract

Method for applying crop protection agents (1) to plants (6) on an agricultural area (3), at least comprising the following steps:a) providing the crop protection agent (1) in the form of an aqueous solution;b) providing an oil (2);c ) Generating droplets (4) of the aqueous solution of the plant protection product (1) with a lipophilic coating (5) containing oil (2); d) applying the droplets (4) to surfaces (7) of plant parts (8) of the plants (6 ).

Description

According to the Federal Environment Agency, around 27,000 tons of plant protection products were brought onto the German market and applied in agricultural plant cultivation in 2019.

During spray application, a large proportion of the plant protection products (particularly pesticides and herbicides) do not get to the place where they are supposed to achieve the desired effect to protect the plants, but into the environment (soil, water, air, living beings) due to runoff and drift of aerosols ). Crop protection agents should usually remain in particular on the leaf surfaces of plants.

Plant protection products are usually applied predominantly in the form of aqueous solutions, mixed with substances to reduce the surface tension of the aqueous solution.

The problem here is that the active ingredient solutions are repelled by the water-repellent and at the same time lipophilic leaf surfaces and the individual drops are broken up into smaller fragments when they hit the leaves and these get into the environment (soil, water, air) as aerosols and droplets. In order to keep these effects low or at least within an acceptable range, larger amounts of substances for reducing the surface tension are usually required. As a result, the amount of liquid required overall (plant protection agent in an aqueous solution with substances for reducing surface tension) is greater, so that overall more liquid also gets into the environment, and the environment may also be contaminated.

Proceeding from this, it is the object of the present invention to at least partially solve the problems described with reference to the prior art. In particular, a particularly advantageous method for applying active substance to parts of plants is to be described, as well as a corresponding device with which the method described can be carried out.

This object is achieved with the invention according to the features of the independent patent claims. Further advantageous configurations are specified in the dependently formulated patent claims and in the description and in particular also in the description of the figures. It should be pointed out that a person skilled in the art can combine the individual features with one another in a technologically sensible manner and thus arrive at further configurations of the invention.

1. a) Bereitstellen des Pflanzenschutzmittels in Form einer wässrigen Lösung;
2. b) Bereitstellen eines Öl;
3. c) Erzeugen von Tröpfchen der wässrigen Lösung des Pflanzenschutzmittels mit einer lipophilen Ummantelung enthaltend Öl;
4. d) Aufbringen der Tröpfchen auf Oberflächen von Pflanzenteilen der Pflanzen.

A method for applying plant protection products to plants on an agricultural area is described here, having at least the following steps:

1. a) providing the plant protection product in the form of an aqueous solution;
2. b) providing an oil;
3. c) generating droplets of the aqueous solution of the plant protection product with a lipophilic coating containing oil;
4. d) applying the droplets to surfaces of plant parts of the plants.

This process takes a new approach to avoiding environmental contamination through spraying techniques. Ultimately, the oil is used to encapsulate the plant protection product in an aqueous solution (similar to the encapsulation of an active ingredient in pharmacy).

A special feature of the method described is, however, that the shell or the sheathing in the method described remains liquid (just like the aqueous solution inside).

It is particularly advantageous if the oil is a fat-based oil and preferably vegetable oil.

It is also advantageous if the surfaces are leaf surfaces, shoot surfaces and/or fruit surfaces.

It is also advantageous if no other surface-active substances are processed with the crop protection agent before the droplets are applied in step d). Plant protection agents with surface-active substances can of course also be used. However, the application of the crop protection product is not dependent on surface-active substances in the crop protection product thanks to the technology described here.

It is also advantageous if step c) is carried out using a micro-encapsulation technique.

In a micro-encapsulation technique, individual encapsulated droplets are produced with a droplet core consisting of the aqueous phase and a lipophilic shell arranged around it. The micro-encapsulation technique preferably uses an effect of the micro-technology such as effects caused by the surface tension of liquids to form the encapsulated droplets. In one embodiment, for example, a concentric jet with an inner jet of plant protection product in an aqueous solution and an outer jet of oil is formed, which, with the help of surface tension, breaks up into individual droplets with a droplet core made of plant protection product in an aqueous solution and with a lipophilic coating of oil. The tearing into individual droplets can be supported or triggered by vibrations, the droplet formation then takes place because the oil and the crop protection agent or their surface tension find a new state of equilibrium.

It is also advantageous if at least one coaxial nozzle with an inner nozzle opening for supplying the crop protection agent and with an annular outer nozzle opening configured concentrically around the inner nozzle opening for supplying the oil is used to carry out the method.

Such a nozzle can be used in a particularly advantageous manner to generate a concentric jet with an inner jet and an outer jet, which breaks up into droplets due to the surface tension of the plant protection product in an aqueous solution in the inner jet and the oil in the outer jet or due to vibrations.

It is also advantageous if vibration is used to generate individual droplets from a concentric jet.

A vibration can be generated with piezo actuators, for example. A vibration preferably acts directly on the coaxial nozzle. In particular, the disintegration of a concentric jet into individual droplets can be accelerated by vibration.

It is also advantageous if a nozzle for providing the crop protection agent and/or the oil is installed on a spray arm.

It is also advantageous if a plurality of nozzles are installed on the spray arm.

A spray arm is, for example, a boom which is attached to an agricultural machine (for example a tractor) and which is moved by the agricultural machine over an agricultural area with plants. The nozzle is in particular the concentric nozzle already described above. A large number of individual nozzles are preferably arranged next to one another on the arm at a predetermined distance from one another, so that plants on an agricultural area can be exposed to the drops over a large area.

It is also advantageous if the surfaces of the parts of the plant are lipophilic and the lipophilic coating interacts with the lipophilic surfaces of the parts of the plant in step d) in such a way that the droplets are reduced in rolling off and/or broken up and the aqueous solution of the plant protection agent is distributed on the Surfaces of the plant parts takes place.

It is also advantageous if the lipophilic coating in step d) forms an intermediary film between the aqueous solution of the crop protection agent and the surfaces of plant parts.

It is also advantageous if the droplets roll off, ricochet off and/or shatter and aerosol formation is reduced when they are applied to the surfaces of the plant parts.

The problem with encapsulation with a solid shell or casing would be that superhydrophobic leaf surfaces (e.g. soybean, wheat, barley etc.) also have a self-cleaning property and as a result solids are washed off the leaf surface with rain and contaminate soil and water. The use of a liquid lipophilic oil shell has significant advantages over a solid shell.

The lipophilic coating or coating of a lipophilic liquid reduces the rolling and smashing of the drops on the lipophilic leaf surface. The two-phase drops also enable the application of water-soluble pesticide substances in the water phase of the aqueous solution. In addition, lipophilic active substances can also be used in the oil phase without the use of further surface-active substances (surfactance).

The smashing (splash) and aerosol formation, as well as the direct rolling of the drops when they hit the leaf surface, was prevented by the lipophilic coating, especially in the case of extremely water-repellent leaves (e.g. soybean, wheat, barley, kohlrabi, white and red cabbage...etc. ) significantly reduced. The loss of liquid from the two-phase drops compared to water was determined and a maximum reduction (at a drop height of individual drops of 50 cm) in oil/water loss from the leaf of 66.14% was achieved.

A device for applying plant protection products to plants on an agricultural area is also to be described here, having at least one coaxial nozzle with an inner nozzle opening and with an annular outer nozzle opening configured concentrically around the inner nozzle opening, the inner nozzle opening being connected to a first supply device for supplying plant protection products and the outer nozzle opening is connected to a second supply device for supplying oil and the coaxial nozzle is set up for generating droplets of the aqueous solution of the plant protection product with a lipophilic coating containing oil.

It should be pointed out that the particular advantages and design features described in connection with the method described above can also be applied and transferred to the device described below.

The device is set up to carry out the method according to one of the preceding claims.

The device particularly preferably has a first supply device for supplying the coaxial nozzle with crop protection agent from a first tank and a second supply device for supplying the coaxial nozzle with oil from a second tank. The supply pressures of the coaxial nozzle with crop protection agent and oil can preferably be regulated in each case and particularly preferably separately regulated in order to adjust the formation of the droplets.

The device preferably also has means for monitoring the formation of droplets. In special design variants, a camera can be installed, which observes the droplets formed when they exit the nozzle and recognizes the parameters of the droplets (e.g. their volume or their exit speed). Such parameters can optionally be used by a controller of the device in order to change settings depending on these parameters. For example, the pressure can be adjusted to adjust the droplets appropriately. Instead of using a camera, other procedures for determining parameters that can be used to control the device are also conceivable. For example, laser-based systems can be used to monitor the number and/or the size of droplets that are produced. For example, parameters such as air pressure, humidity and ambient temperature can be taken into account and settings of the device can be changed depending on these parameters.

In further embodiment variants, it is also possible for the size of the inner nozzle outlet opening and/or the outer nozzle outlet opening to be variable. These sizes can also be adjusted depending on the parameters of the droplets.

• 1: eine schematische Darstellung einer hier beschriebenen Vorrichtung zur Aufbringung von Pflanzenschutzmittel,
• 2: eine Anwendung einer beschriebenen Vorrichtung mit einer Landmaschine zur Bearbeitung einer Agrarfläche,
• 3: ein schematisches Ablaufdiagramm des beschriebenen Verfahrens, und
• 4: ein Diagramm zu einer Versuchsreihe, die zur Validierung der beschriebenen Vorrichtung und des beschriebenen Verfahrens durchgeführt wurde.

The invention and the technical context of the invention are explained in more detail below with reference to the figures. The figures show preferred exemplary embodiments, which do not limit the invention. It should be pointed out in particular that the figures and in particular the proportions shown in the figures are only schematic. Show it:

• 1 : a schematic representation of a device described here for the application of crop protection agents,
• 2 : an application of a device described with an agricultural machine for processing an agricultural area,
• 3 : a schematic flowchart of the method described, and
• 4 : a diagram of a series of tests carried out to validate the device and method described.

1 shows schematically a device 23 for carrying out the method described. The essential element of the device 23 is the coaxial nozzle 9 with the inner nozzle opening 10 and the outer nozzle opening 11. The device 23 or the coaxial nozzle 9 is set up in such a way that an aqueous solution of the crop protection agent 1 exits through the inner nozzle opening 10. The device 23 or the coaxial nozzle 9 is also set up in such a way that the oil exits through the outer nozzle opening 11 . The aqueous solution of the crop protection agent 1 is provided to the coaxial nozzle 9 by a first supply device 15 which conveys the aqueous solution of the crop protection agent 1 from a first tank 20 to the coaxial nozzle 9 . The oil 2 is made available to the coaxial nozzle 9 by a second supply device 16 which conveys the oil 2 from a second tank 21 to the coaxial nozzle 9 . When the aqueous solution of crop protection agent 1 and the oil 2 emerges from the coaxial nozzle 9, a concentric jet 12 is preferably initially formed with an inner jet 18 of aqueous solution of crop protection agent 1 and an outer jet 19 of oil 2. Through various effects and in particular through vibrations and Surface tensions of the aqueous solution of the crop protection product 1 and the oil 2 break the jet into droplets 4. The droplets 4 are almost spherical in the floating state and have a lipophilic coating 5, which consists of the oil 2, and an aqueous droplet core 17, which consists of the aqueous Solution of the crop protection agent 1 is formed. With droplets 4 produced in this way, the method described and the device 23, the advantages described above can be realized and the amount of crop protection agent 1 which does not remain on the surfaces of the plant parts can be greatly reduced.

2 shows an example of how a described device 23 and the described method can be used in practice to plants 6 or their plant parts 8 and surfaces 7 on an agricultural area 3 with the plant protection product 1, or the droplets 4 containing the plant protection product 1 would be treated. A plurality of devices 23 or a plurality of coaxial nozzles 9 of a device 23 are preferably attached to a spray arm 13 which is held by an agricultural machine 14 and is moved over the agricultural area 3 .

3 shows a schematic flow chart of the described method with method steps a), b), c) and d). The crop protection agent 1 is provided in the form of an aqueous solution in step a) and an oil 2 is provided in step b). Then, in step c), droplets 4 of the aqueous solution of the plant protection product 1 with a lipophilic coating containing oil 2 are produced and the drops and the droplets 4 are then applied to the surfaces 7 of plant parts 8 of plants 6 in step d).

The influence of the oil coating was examined in more detail with a series of tests based on the 4 is explained. The influence of an oil coating on droplets 4 of an aqueous solution and the influence of the oil coating on the type of distribution of the aqueous solution that occurs when the droplets 4 fall onto superhydrophobic surfaces 7 of plant parts 8 were investigated here. The surfaces of soybeans were investigated here as superhydrophobic surfaces 7 of plant parts, the properties of which are determined, among other things, by a very high alcohol content, in particular long-chain primary alcohols in wax mixtures. Surfaces 7 of nasturtium leaves (Tropaeolum majus) were also investigated as superhydrophobic surfaces of plant parts 8 .

Water droplets that hit such a superhydrophobic surface 7 from a predetermined height are distributed by various effects. For example, the water droplets bounce off or roll off the leaf surface. The water drops can also be smashed. Only a small part of the volume of water contained in a quantity of water drops adheres to the surface 7 .

87.7% of the water volume of pure water droplets falling vertically from a height of 50 cm onto a superhydrophobic surface 7 of this type does not remain on the leaf surface, but is distributed by the effects described.

Even a small angle between the impact direction and the normal direction to the leaf surface of e.g. 6° ensures that the water volume is distributed almost 100% and almost nothing remains on the leaf surface, especially because water droplets roll off the surface.

Since the leaves of many cultivated plants such as wheat, soybeans or cabbage have superhydrophobic properties, it is common in the agricultural sector to use additives in a spray of aqueous crop protection agents 1 .

Here, two-phase droplets 4 consisting of an outer oil layer of rapeseed oil and an inner core of water were produced and it was investigated how these droplets 4 behave after hitting superhydrophobic surfaces 7 of soybeans and nasturtium. The fraction of liquid that does not remain on the surfaces after impact but is distributed was studied using a gravimetric technique in which the droplets consisting of different volume ratios of oil 2 and water were examined. In addition, different impact heights were examined. A thick oil jacket produces a greater reduction in the amount of liquid not remaining on the surfaces 7.

Drops with a water-oil volume ratio of 1:1 show that only 10.25% of the liquid is spread (particularly in the form of droplets, rolls off), and the rest (89.74%) remain on the surface 7. Reducing the oil content by 50% to 25% of the total volume (water-oil volume ratio of 1:3) causes 21.57% of the liquid to be distributed (particularly in the form of droplets rolling off) and 78.43% on the surface 7 remains.

Both components (oil and water) can be used as carriers for active substances (e.g. pesticides). The reduction in distribution through the use of aqueous droplets 4 with an oil coat reduces the contamination of the environment through the formation of aerosols and thus also reduces the consumption of the active substance contained in the droplet (e.g. crop protection agent 1).

The wetting behavior, which determines the adhesion of the liquid of the droplets 4 to the surfaces 7 and also the ricocheting off of the droplets 4 from the surfaces 7, can be decisively described using the contact angle of the respective droplets 4 with the surface 7. For pure (demineralized) water, a mean contact angle of 157.43°±3.69° was measured on the leaf surfaces examined here. The spherical shape of the droplets 4 is therefore retained almost completely when they hit the leaf surface, and the droplets 4 can very easily ricochet off or roll off the leaf surface.

The oil 2 greatly reduces the contact angle. An average contact angle of 39.67°±3.71° was measured on the leaf surfaces. For this reason, the drop shape does not remain on the leaf surface.

During the investigation, the impact behavior of droplets 4 consisting of demineralized water colored with patent blue V (DW + PV = demineralized water + patent blue V) was compared with the impact behavior of water droplets containing oil (oil + C).

The 4 shows in each case how much of the total amount of liquid applied in the form of droplets 4 is distributed on the surfaces 7 and does not remain on the surface 7 depending on the tested drop heights 22 of 30 cm [centimeters], 40 cm [centimeters] and 50 cm [Centimeter].

The table below shows those in the 4 shown test results shown again. drop height Splashing DW splashing [cm] [%] (WP: ÖP, 3:1) [%] 50 (87.71 ± 7.28%) (21.57 ± 7.42%) 40 (70.80 ± 10.44%) (18.96 ± 4.97%) 30 (49.61 ± 21.73%) (18.55 ± 3.13%)

It can be seen that the use of the oil jacket (right-hand column) results in a drastic reduction in the distributed quantity of liquid that does not remain on the surface 7, regardless of the drop height 22.

It should also be said about the test series that the tests were carried out with horizontally aligned blade surfaces without tilting the blade surfaces. Leaves of the so-called large nasturtium (Tropaeolum majus) were used. The droplets 4 used in the experiments had a droplet volume of about 47 μl. A volume fraction of 11.65 ± 5.84 µl of oil 2 and a volume fraction of water of 34.54 ± 0.82 µl were contained in the droplets 4 OIL + C. This corresponds to 25.23% oil 2 and 74.77% water. The mixing ratio of water to oil 2 was therefore approximately 3:1.

Reference List

1

crop protection products

2

oil

3

agricultural area

4

droplet

5

lipophilic coating

6

plant

7

surface

8th

plant part

9

coaxial nozzle

10

inner nozzle opening

11

outer nozzle opening

12

concentric beam

13

spray arm

14

agricultural machine

15

first utility

16

second utility

17

watery drop core

18

inner beam

19

outer beam

20

first tank

21

second tank

22

drop height

23

contraption

Claims (14)

Method for applying plant protection products (1) to plants (6) on an agricultural area (3), at least having the following steps: a) providing the crop protection agent (1) in the form of an aqueous solution; b) providing an oil (2); c) generating droplets (4) of the aqueous solution of the crop protection agent (1) with a lipophilic coating (5) containing oil (2); d) application of the droplets (4) to surfaces (7) of plant parts (8) of the plants (6). procedure after claim 1 , wherein the oil (2) is a fat-based oil (2) and preferably vegetable oil (2). Method according to any one of the preceding claims, wherein the surfaces (7) are leaf surfaces, shoot surfaces and/or fruit surfaces. Method according to one of the preceding claims, wherein before the application of the droplets (4) in step d) no further surface-active substances are processed with the crop protection agent (1). A method according to any one of the preceding claims, wherein step c) is performed with a micro-encapsulation technique. Method according to one of the preceding claims, in which, for carrying out the method, at least one coaxial nozzle (9) with an inner nozzle opening (10) for providing the crop protection agent (1) and with an annular outer nozzle opening (11) configured concentrically around the inner nozzle opening (10). ) is used to provide the oil (2). procedure after claim 5 or 6 wherein vibration is applied to produce individual droplets (4) from a concentric jet (12). Method according to one of the preceding claims, in which a coaxial nozzle (9) for providing the crop protection agent and/or the oil is installed on a spray arm (13). procedure after claim 8 wherein a plurality of coaxial nozzles (9) are installed on the spray arm (13). Method according to one of the preceding claims, wherein the surfaces (7) of the plant parts (8) are lipophilic and the lipophilic coating (5) interacts with the lipophilic surfaces (7) of the plant parts (8) in step d) in such a way that rolling and / or breaking up the droplets (4) is reduced and the aqueous solution of the plant protection agent (1) is distributed on the surfaces (7) of the plant parts (8). procedure after claim 10 , wherein the lipophilic coating (5) in step d) forms a mediating film between the aqueous solution of the crop protection agent (1) and the surfaces (7) of plant parts (8). procedure after claim 10 or 11 , wherein rolling, rebounding and/or smashing of the droplets (4) and aerosol formation when applied to the surfaces (7) of the plant parts (8) are reduced. Device (23) for applying crop protection agents (1) to plants (6) on an agricultural area (3), having at least one coaxial nozzle (9) with an inner nozzle opening (10) and with an annular outer nozzle opening (10) configured concentrically around the inner nozzle opening Nozzle opening (11), wherein the inner nozzle opening (10) is connected to a first supply device (15) for supplying crop protection agent (1) and the outer nozzle opening (11) is connected to a second supply device (16) for supplying oil and the Coaxial nozzle (9) for generating droplets (4) of the aqueous solution of the crop protection agent (1) with a lipophilic coating (5) containing oil (2) is set up. device after Claim 13 set up to carry out the method according to one of the preceding claims.

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