Tracer composition

Abstract

The present disclosure provides a tracer composition, which includes: a fluorescent molecule that fluoresces when exposed to an excitation wavelength and thereby emits photons with a wavelength between 400 and 600 nm; and a gelling agent.

Description

Technical Field

[0001] The present invention relates to tracer compositions and more particularly to tracer compositions that can be used to determine spray deposition comprising the composition. The invention also extends to methods of assessing spray deposition using the tracer compositions. Background Art

[0002] Sprays are frequently used in agriculture to treat plant and soil surfaces with pesticides, feeds and other substances. Minimal deposition on the surface is necessary to be effective. Therefore, in order to ensure that minimal deposition has been achieved, methods have been developed to detect and analyze the extent and thoroughness of spray deposition.

[0003] One method of determining coverage is to use water-sensitive paper that is distributed among the crop and indicates where the spray has wetted it. This method has many limitations. Specifically, this technology is broadly qualitative and gives little indication of the amount of spray on the crop leaves. Furthermore, the paper is not considered a realistic substitute for the leaves. The method requires that the water-sensitive paper be dispersed among the crop. In practice, this requires the paper to be attached directly to the crop or to a supporting structure. This usually requires the paper to be attached manually, which is time-consuming. Finally, the use of water-sensitive paper requires completely dry conditions, which greatly affects the time it can be used.

[0004] For crop sprays, detectable tracers have been developed where the spray contains a visual or fluorescent tracer. An example of a visual tracer is kaolin, which can be added to the spray and leaves a white residue on the surface of the leaves as the spray dries. The spray coverage can then be checked visually. Alternatively, when a fluorescent tracer is added to the spray, coverage can be assessed with UV light in the dark. While these methods are an improvement over water-sensitive paper, they are still broadly qualitative. In addition, the tracers used are often not food safe, which may require the crop to be destroyed.

[0005] Another way to assess crop spray coverage is through laboratory testing. This technique requires spraying crops or artificial targets with a detectable substance, such as a detectable pesticide, colorant, or fluorescent marker. The deposit can be photographed to allow analysis of the cover. Afterwards, the deposit can be washed off and quantified to determine the amount that has been deposited. This allows various spray techniques to be tested and modified to improve coverage. However, this method is expensive and time consuming. In addition, artificial targets may be unrealistic substitutes for leaves, and any crops used in the laboratory for analysis may need to be destroyed after testing. Summary of the invention

[0006] The present invention arises from work performed by the inventors in an attempt to overcome the problems associated with the prior art.

[0007] According to a first aspect of the present invention, there is provided a tracer composition, comprising:

[0008] - fluorescent molecules that fluoresce when exposed to an excitation wavelength and thereby emit photons with a wavelength between 400 and 600 nm; and

[0009] - Gelling agent.

[0010] Advantageously, the tracer composition may be used to assess spray deposition.The term "spray deposition" may be understood as a measure of spray coverage over an area, the volume of liquid comprising the spray deposit, the size of the spray deposit on a surface and / or the distribution of the deposit over an area.

[0011] For example, the tracer composition can be added to a spray tank with a plant protection product (PPP), which can be applied to plants or other structures or substrates. The term plant protection product (PPP) can refer to any substance that can be applied to plants or other structures or substrates in agriculture. For example, PPP can include herbicides, insecticides, acaricides, nematicides, molluscicides, bactericides, fungicides, adjuvants, fertilizers, hormones or inducers. The tracer composition enables the determination of the coverage percentage and amount of the PPP deposited on the plant.

[0012] Preferably, the fluorescent molecules emit photons at a wavelength between 450 and 650 nm, more preferably between 475 and 625 nm and most preferably between 500 and 600 nm. Advantageously, chlorophyll A and chlorophyll B do not absorb or emit photons in this range.

[0013] Preferably, the fluorescent molecule fluoresces when exposed to an excitation wavelength of between 150 and 700 nm, more preferably between 300 and 650 nm or between 450 and 600 nm, and most preferably between 460 and 550 nm or between 465 and 500 nm.

[0014] The fluorescent molecule may be leucine. However, in a preferred embodiment, the fluorescent molecule is food safe. Preferably, the tracer composition is food safe. Advantageously, the tracer composition may be used for crops.

[0015] In a preferred embodiment, the fluorescent molecule is a compound of formula (I):

[0016]

[0017] , where R 1 to R 8 Each of is independently hydrogen or C 1-5 alkyl,

[0018] or a salt and / or solvate thereof.

[0019] More preferably, the fluorescent molecule is a compound of formula (Ia):

[0020]

[0021] , where R 1 to R 8 Each of is as defined above,

[0022] or a salt and / or solvate thereof.

[0023] Understandably, C 1-5 The alkyl group may be methyl, ethyl, propyl, butyl or pentyl.

[0024] In a preferred embodiment, R 1 to R 8 Each may independently be hydrogen, methyl or ethyl.

[0025] Preferably, R 1 It's hydrogen.

[0026] Preferably, R 2 It is methyl or ethyl, and most preferably it is methyl.

[0027] Preferably, R 3 It is methyl or ethyl, and most preferably it is methyl.

[0028] Preferably, R 4 It's hydrogen.

[0029] Preferably, R 5 It's hydrogen.

[0030] Preferably, R 6 It's hydrogen.

[0031] Preferably, R 7 It's hydrogen.

[0032] Preferably, R 8 It's hydrogen.

[0033] Therefore, the fluorescent molecule can be riboflavin 5'-monophosphate or a salt and / or solvate thereof. The salt can be a lithium salt, a sodium salt, a potassium salt, a rubidium salt, a beryllium salt, a magnesium salt, a calcium salt or a strontium salt. In some embodiments, the fluorescent molecule is riboflavin 5'-monophosphate sodium salt or a solvate thereof. In some embodiments, the fluorescent molecule is riboflavin 5'-monophosphate sodium salt dihydrate.

[0034] The tracer composition may include a fluorescent molecule at a concentration of at least 0.0001 wt%, more preferably at least 0.001 wt%, at least 0.005 wt% or at least 0.01 wt%, and most preferably at least 0.02 wt%, at least 0.04 wt%, at least 0.06 wt% or at least 0.08 wt%. The tracer composition may include a fluorescent molecule at a concentration of less than 50 wt%, more preferably less than 20 wt%, less than 10 wt%, less than 5 wt%, less than 2 wt% or less than 1 wt%, and most preferably less than 0.8 wt%, less than 0.6 wt%, less than 0.4 wt% or less than 0.2 wt%. The tracer composition may comprise fluorescent molecules in a concentration between 0.0001 and 50 wt %, more preferably between 0.001 and 50 wt % or between 0.005 and 10 wt % or between 0.01 and 1 wt %, and most preferably between 0.02 and 0.8 wt %, between 0.04 and 0.6 wt %, between 0.06 and 0.4 wt % or between 0.08 and 0.2 wt %.

[0035] The tracer composition may include a gelling agent in a concentration of at least 5 wt%, more preferably at least 10 wt%, at least 20 wt%, at least 30 wt%, at least 40 wt% or at least 50 wt%, and most preferably at a concentration of at least 60 wt%, at least 65 wt% or at least 67.5 wt%. The tracer composition may include a gelling agent in a concentration of less than 99 wt%, preferably less than 95 wt%, less than 90 wt%, less than 85 wt% or less than 80 wt%, and most preferably less than 77.5 wt%, less than 75 wt% or less than 72.5 wt%. The tracer composition may include a gelling agent in a concentration between 10 and 99 wt%, more preferably between 20 and 95 wt%, between 30 and 90 wt%, between 40 and 85 wt% or between 50 and 80 wt%, and most preferably between 60 and 77.5 wt%, between 65 and 75 wt% or between 67.5 and 72.5 wt%.

[0036] The gelling agent may include a carbohydrate, and preferably a sugar or a polysaccharide or a salt and / or a solvate thereof. The sugar may include a disaccharide or a salt and / or a solvate thereof. The disaccharide may be sucrose, lactulose, lactose, maltose, trehalose, cellobiose, chitobiose or a salt and / or a solvate thereof. Preferably, the disaccharide is sucrose or a salt and / or a solvate thereof. The polysaccharide may be linear or cyclic. Therefore, the polysaccharide may be a cyclodextrin, agarose or gellan gum. The cyclodextrin may be an alpha-cyclodextrin, a beta-cyclodextrin or a gamma-cyclodextrin.

[0037] In some embodiments, the gelling agent may include agar. It is understood that agar includes agarose and agaropectin. It is understood that agaropectin includes D-glucuronic acid and pyruvic acid.

[0038] The tracer composition may include a sugar in a concentration of at least 5wt%, more preferably at least 10wt%, at least 20wt% or at least 30wt%, and most preferably at a concentration of at least 32.5wt%, at least 35wt% or at least 37.5wt%. The tracer composition may include a sugar in a concentration of less than 90wt%, more preferably less than 80wt%, less than 70wt% or less than 60wt%, and most preferably less than 50wt%, less than 45wt% or less than 42.5wt%. The tracer composition may include a sugar in a concentration between 5 and 90wt%, more preferably between 10 and 80wt%, between 20 and 70wt% or between 30 and 60wt%, and most preferably between 32.5 and 50wt%, between 35 and 45wt% or between 37.5 and 42.5wt%.

[0039] The gelling agent may include an alcohol, and preferably includes a glycol. The glycol may be polyethylene glycol. Thus, the glycol may be polyethylene glycol (PEG). Alternatively, the gelling agent includes C 1-10 Preferably, the gelling agent comprises C 1-10 Diol or its salt and / or solvate. 1-10 The diol may comprise between 2 and 10 hydroxyl groups. More preferably, the gelling agent comprises C 1-5 Diol. C 1-5 The diol may include between 2 and 5 hydroxyl groups. Most preferably, the gelling agent includes C 2-4 Diol. C 2-4 The diol may include between 2 and 4 hydroxyl groups. In a most preferred embodiment, the gelling agent comprises glycerol or a salt and / or solvate thereof.

[0040] The tracer composition may include an alcohol in a concentration of at least 5 wt%, more preferably at least 10 wt%, at least 15 wt% or at least 20 wt%, and most preferably at a concentration of at least 22.5 wt%, at least 25 wt%, at least 27.5 wt% or at least 30 wt%. The tracer composition may include an alcohol in a concentration of less than 90 wt%, more preferably less than 70 wt%, less than 60 wt% or less than 50 wt%, and most preferably less than 40 wt%, less than 37.5 wt%, less than 35 wt% or less than 32.5 wt%. The tracer composition may include an alcohol in a concentration between 5 and 90 wt%, more preferably between 10 and 70 wt%, between 15 and 60 wt% or between 20 and 50 wt%, and most preferably between 22.5 and 40 wt%, between 25 and 37.5 wt%, between 27.5 and 35 wt% or between 30 and 32.5 wt%.

[0041] Preferably, the gelling agent comprises sugar and C 1-10 Diols Advantageously, the inventors have discovered that the combination of sugars and polyols synergistically enhances the fluorescence of the fluorescent molecule.

[0042] The weight ratio of sugar to alcohol may be between 1:10 and 10:1, more preferably between 5:1 and 1:5, between 1:4 and 4:1, between 1:3 and 3:1 or between 1:2 and 2:1, most preferably between 1.75:1 and 1:1, between 1.5:1 and 1.1:1 or between 1.3:1 and 1.2:1.

[0043] Preferably, the composition includes a stabilizer that improves the photostability of the fluorescent molecule. The stabilizer can improve the photostability of the fluorescent molecule by absorbing photons. It is understood that the wavelength of the photons absorbed by the stabilizer can vary depending on the fluorescent molecule. In one embodiment, the stabilizer can absorb photons with a wavelength between 100 and 500nm, more preferably between 150 and 400nm or between 175 and 350nm, and most preferably between 200 and 325nm. It is understood that light with a wavelength between 100 and 280nm, also known as ultraviolet C, is absorbed by the ozone layer and the atmosphere. Therefore, there are no photons with these wavelengths in the natural light on the ground. For this reason, the upper half of the above range may be more important. In some embodiments, the stabilizer can absorb photons with a wavelength between 280 and 500nm, more preferably between 280 and 470nm or between 280 and 400, and most preferably between 280 and 350nm. Advantageously, the stabilizer protects the fluorescent molecule from the influence of light of these wavelengths.

[0044] Alternatively or additionally, the stabilizer may be a free radical scavenger. Advantageously, the stabilizer protects the fluorescent molecule from free radicals.

[0045] Stabilizers can include thiosulfuric acid, ascorbic acid, beta-carotene, ethylenediaminetetraacetic acid (EDTA), thiourea, methionine, thiosulfuric acid, butylated hydroxytoluene (BHT) or its salt and / or solvate. Methionine can be present in a racemic mixture. Alternatively, methionine can include D-methionine or L-methionine. Salts can be lithium salts, sodium salts, potassium salts, rubidium salts, beryllium salts, magnesium salts, calcium salts or strontium salts.

[0046] Preferably, the stabilizer comprises a compound of formula (II):

[0047]

[0048] , where R 9 to R 12 Each of is independently hydrogen or C 1-5 alkyl,

[0049] or a salt and / or solvate thereof.

[0050] More preferably, the stabilizer comprises a compound of formula (IIa):

[0051]

[0052] , where R 9 to R 12 Each of is as defined above,

[0053] or a salt and / or solvate thereof.

[0054] Preferably, R 9 to R 12 Each of is hydrogen. Therefore, the stabilizer may include ascorbic acid, and more preferably includes L-ascorbic acid or a salt and / or solvate thereof.

[0055] The tracer composition may include a stabilizer in a concentration of at least 0.01 wt%, more preferably at least 0.1 wt%, at least 0.5 wt%, at least 1 wt% or at least 1.5 wt%, and most preferably at a concentration of at least 2 wt%, at least 2.5 wt%, at least 3 wt% or at least 3.5 wt%. The tracer composition may include a stabilizer in a concentration of less than 90 wt%, more preferably less than 50 wt%, less than 30 wt% or less than 10 wt%, and most preferably less than 7.5 wt%, less than 5 wt%, less than 4.5 wt% or less than 4 wt%. The tracer composition may include a stabilizer in a concentration between 0.01 and 90 wt%, more preferably between 0.1 and 50 wt%, between 0.5 and 30 wt% or between 1 and 10 wt%, and most preferably between 2 and 7.5 wt%, between 2.5 and 5 wt%, between 3 and 4.5 wt% or between 3.5 and 4 wt%.

[0056] The tracer composition may include a solvent. The solvent may include water or an organic solvent such as alcohol. The alcohol may be ethanol. In some embodiments, the solvent may include an organic solvent such as alcohol to increase the solubility of the components in the composition. However, preferably, the solvent is water, and more preferably deionized water. Advantageously, water is the same solvent used in most commercially available plant protection products (PPP). The tracer composition may include a solvent having a concentration of at least 1wt%, more preferably at least 5wt%, at least 10wt% or at least 15wt%, and most preferably at a concentration of at least 20wt%, at least 22wt%, at least 23wt% or at least 24wt%. The tracer composition may include a solvent having a concentration of less than 90wt%, more preferably less than 70wt%, less than 50wt% or less than 40wt%, and most preferably less than 30wt%, less than 28wt%, less than 26wt% or less than 25wt%. The tracer composition may include a solvent in a concentration between 1 and 90 wt %, more preferably between 5 and 70 wt %, between 10 and 50 wt % or between 15 and 40 wt %, and most preferably in a concentration between 20 and 30 wt %, between 22 and 28 wt %, between 23 and 26 wt % or between 24 and 25 wt %.

[0057] It will be appreciated that the tracer composition may be added to a plant protection product (PPP).

[0058] Therefore, according to a second aspect, there is provided a plant protection composition comprising:

[0059] - the tracer composition of the first aspect; and

[0060] - Plant protection products (PPP).

[0061] PPP may be as defined with respect to the first aspect. It will be appreciated that PPP may be a substance configured to control pests. Thus, PPP may include a herbicide, an insecticide, a miticide, a nematicide, a molluscicide, a bactericide and / or a fungicide. PPP may be a commercially available pesticide.

[0062] PPP can be a biological pesticide. For example, PPP can include fungi or their spores. Fungi can be pathogens that control pests. Therefore, the pesticide can include Ampelomyces quisqualis, Beauveria bassiana and / or Bacillus thuringiensis.

[0063] Alternatively or in addition, the PPP agent can include a small molecule for controlling pests.PPP can include myclobutanil, avermectin, spinosad, pyrimethanil, carbonic acid, thiacloprid, chlorpyrifos, azoxystrobin, chlorfenapyr, methoxyfenozide, iprodione, captan, fenhexamid, clofenazine, boscalid, pyraclostrobin, pendimethalin, cyprodinil, fludioxonil, tebufenamide or its salt and / or solvate.Salt can be a lithium salt, sodium salt, potassium salt, rubidium salt, beryllium salt, magnesium salt, calcium salt or strontium salt.Specifically, the salt of carbonic acid can be sodium bicarbonate or potassium bicarbonate, and preferably potassium bicarbonate. It will be appreciated that the term "captan" may refer to the compound identified by the IUPAC name (3aR,7aS)-2-[(trichloromethyl)sulfanyl]-3a,4,7,7a-tetrahydro-1H-isoindole-1,3(2H)-dione.

[0064] The plant protection composition may comprise the tracer composition in an amount of at least 0.01% (v / v), more preferably at least 0.1% (v / v), at least 0.25% (v / v), at least 0.5% (v / v) or at least 0.75% (v / v), and most preferably at least 1% (v / v). The plant protection composition may comprise the tracer composition in an amount of less than 50% (v / v), more preferably less than 40% (v / v), less than 30% (v / v), less than 20% (v / v) or less than 10% (v / v), and most preferably less than 5% (v / v). The plant protection composition may comprise the tracer composition in an amount between 0.01% and 50% (v / v), more preferably between 0.1% and 40% (v / v), between 0.25% and 30% (v / v), between 0.5% and 20% (v / v) or between 0.75% and 10% (v / v), and most preferably between 1% and 5% (v / v).

[0065] The plant protection composition may comprise at least 20% (v / v), more preferably at least 40% (v / v), at least 60% (v / v) or at least 80% (v / v), and most preferably at least 90% (v / v) or at least 95% (v / v) of the amount of PPP. The plant protection composition may comprise less than 99.99% (v / v), more preferably less than 99.9% (v / v), and most preferably less than 99% (v / v) of the amount of PPP. The plant protection composition may comprise between 20% and 99.99% (v / v), more preferably between 60% and 99.9% (v / v) or between 40% and 99.9% (v / v), and most preferably between 90% and 99% (v / v) or between 95% and 99% (v / v) of the amount of PPP.

[0066] Preferably, the pH of PPP is less than 10 at 20°C, more preferably less than 9 at 20°C or less than 8 at 20°C, and most preferably less than 7 at 20°C. Preferably, the pH of PPP is greater than 4 at 20°C, more preferably greater than 6 at 20°C.

[0067] Alternatively, the tracer composition may be diluted for analysis without being combined with the PPP.

[0068] Thus, in a further aspect, there is provided an analytical composition comprising:

[0069] - the tracer composition of the first aspect; and

[0070] -Solvent.

[0071] The solvent may comprise water and / or alcohol. Preferably, the solvent comprises water.

[0072] The assay composition may include at least 0.01% (v / v), more preferably at least 0.1% (v / v), at least 0.25% (v / v), at least 0.5% (v / v) or at least 0.75% (v / v), and most preferably at least 1% (v / v) of the tracer composition. The assay composition may include less than 50% (v / v), more preferably less than 40% (v / v), less than 30% (v / v), less than 20% (v / v) or less than 10% (v / v), and most preferably less than 5% (v / v) of the tracer composition. The assay composition may comprise an amount of the tracer composition between 0.01% and 50% (v / v), more preferably between 0.1% and 40% (v / v), between 0.25% and 30% (v / v), between 0.5% and 20% (v / v) or between 0.75% and 10% (v / v), and most preferably between 1% and 5% (v / v).

[0073] The analysis composition may include at least 20% (v / v), more preferably at least 40% (v / v), at least 60% (v / v) or at least 80% (v / v), and most preferably at least 90% (v / v) or at least 95% (v / v) of the amount of solvent. The analysis composition may include less than 99.99% (v / v), more preferably less than 99.9% (v / v), and most preferably less than 99% (v / v) of the amount of solvent. The analysis composition may include between 20% and 99.99% (v / v), more preferably between 60% and 99.9% (v / v) or between 40% and 99.9% (v / v), and most preferably between 90% and 99% (v / v) or 95% and 99% (v / v) of the amount of solvent.

[0074] According to a third aspect, there is provided an apparatus comprising:

[0075] a light emitting device for selectively illuminating a surface with a first wavelength, wherein the surface has a material thereon;

[0076] an imaging device for generating a first fluorescent image in response to illuminating the surface at the first wavelength; and

[0077] A processor is configured to process the fluorescent image to determine coverage information and / or dosage information of the material.

[0078] The light emitting device may be a dual wavelength light emitting device for selectively illuminating a surface at a first wavelength and a second wavelength;

[0079] the imaging device generates a first visual image in response to illuminating the surface at the second wavelength; and

[0080] The processor is configured to: process the first visual image to generate a mask indicating an area of ​​the first visual image; generate a second fluorescent image by masking the first fluorescent image using the mask; and process the second fluorescent image to determine the coverage information and / or the dose information of the material.

[0081] The first wavelength may be in the range of 400 to 500 nm.

[0082] The second wavelength may be in the range of 500 to 600 nm.

[0083] The light emitting device may include at least one light emitting diode. Each of the at least one light emitting diode may be placed in a back focal plane of the light emitting device to provide a uniform illumination pattern for illuminating the surface.

[0084] The light emitting device may further include at least one of the following:

[0085] a first plano-convex lens;

[0086] at least one emission filter; and

[0087] The second plano-convex lens.

[0088] The surface may include vegetation or a part thereof.

[0089] According to a further aspect, there is provided a method comprising:

[0090] selectively irradiating a surface with a first wavelength, wherein the surface has a material;

[0091] generating a first fluorescent image of the surface in response to illumination at the first wavelength;

[0092] The first fluorescent image is processed to determine coverage information and / or dose information of the material.

[0093] The material may be bacteria. Thus, the method of the further aspect may be used to detect bacteria on a surface. For example, the first wavelength may cause the bacteria to fluoresce.

[0094] However, in a preferred embodiment, the material is the tracer composition of the first aspect or the plant protection composition of the second aspect. Thus, the method may comprise first spraying the surface with a spray composition comprising the tracer composition of the first aspect or the plant protection composition of the second aspect. The method may comprise processing the first fluorescent image to determine coverage information and / or dosage information of the tracer composition or the plant protection composition.

[0095] The surface can include plants or a part thereof. In certain embodiments, plants include crop plants. As used herein, the term "crop plants" includes any edible or inedible plants, including ornamental plant species with commercial value that are planted and cultivated for commercial purposes. Therefore, crop plants include flowers and non-flower plants, trees, vegetable plants, turf and ground cover plants. It will be understood that trees include fruit trees. The term "plant" is intended to include germinated seeds, sprouted seedlings and formed vegetation, including roots and above-ground parts (e.g., leaves, stems, flowers, fruits, branches, branches, roots, etc.). The term "turf" used herein refers to grass grown in a desired or intentionally planned and maintained area, such as a lawn. Turf also refers to a lawn, wherein the surface layer of the ground is composed of a grass mat and grass roots.

[0096] Non-limiting specific examples of crop plants include members of the genera Allium, Celery, Asparagus, Brassica, Camellia, Cicera, Citrus, Coffea, Glycine max, Fragaria, Glycine max, Helianthus annuus, Lactuca sativa, Lentil, Linum usitatissimum, Malus, Phaseolus vulgaris, Pisum sativum, Prunus, Pyrus, Ricinus communis, Rubus, Sinapis, Solanum, Spinach, Theobroma cacao, Vanilla, Vicia faba, Vitis vinifera, and Zea mays. More specifically, crop plants can include apple trees, asparagus, beans, broccoli, Brussels sprouts, cabbage, cocoa trees, carrot plants, castor oil plants, cauliflower, celery, cherry trees, chickpea plants, coffee plants, grapevines, Jerusalem artichokes, leeks, lentil plants, lettuce, linseed, corn, mustard, onions, orange trees, peach trees, pea plants, pear trees, potato plants, rapeseed, raspberry plants, spinach, strawberry plants, sunflowers, tea trees, tomato plants and vanilla plants. Legumes can include black beans, monk beans, butter beans, common beans, faba beans, fava beans, French beans, green beans, kidney beans, lima beans, pinto beans, runner beans and / or soybeans.

[0097] Advantageously, the method allows a user to determine spray deposition of PPP on crop plants.

[0098] The method may further comprise:

[0099] selectively irradiating the surface with the first wavelength and the second wavelength;

[0100] generating a first visual image of the surface in response to illumination at the second wavelength;

[0101] processing the first visual image to generate a mask indicating an area of ​​the first visual image;

[0102] generating a second fluorescent image by masking the first fluorescent image using the mask; and

[0103] The second fluorescent image is processed to determine the coverage information and / or the dose information of the material.

[0104] The first wavelength may be between 150 and 700 nm, between 300 and 650 nm, between 350 and 600 nm, or between 400 and 500 nm. In some embodiments, the wavelength of the photon is not 460 nm. This is because photons with a wavelength of 460 nm may be absorbed by chlorophyll. Therefore, the first wavelength may be between 465 and 500 nm.

[0105] The second wavelength is preferably different from the first wavelength.The second wavelength may be between 450 and 650 nm, between 475 and 625 nm or between 500 and 600 nm.

[0106] The first fluorescent image may record the emission of light having a predetermined wavelength in the region. The predetermined wavelength is preferably different from the first wavelength. The predetermined wavelength may be between 450 and 650 nm, more preferably between 475 and 625 nm, and most preferably between 500 and 600 nm.

[0107] The method may further comprise:

[0108] generating a plurality of candidate first visual images under different illumination intensities; and

[0109] One of the plurality of candidate first visual images is selected as the first visual image.

[0110] The method may further comprise:

[0111] generating a plurality of candidate first fluorescent images under different illumination intensities; and

[0112] One of the plurality of candidate first fluorescent images is selected as the first fluorescent image.

[0113] The selection may select the best candidate based on a metric. The metric may include determining the candidate with the largest number of pixels having pixel values ​​above a first threshold and / or the candidate with the largest number of pixels having pixel values ​​below a second threshold.

[0114] Determining the coverage information may include determining the percentage of the surface covered by the material. Determining the percentage of the surface covered by the material may include determining the number of fluorescent pixels as a percentage of all pixels of the corresponding fluorescent image, wherein fluorescent pixels are pixels having a pixel value above a fluorescence threshold.

[0115] Alternatively or additionally, determining said dosage information may comprise:

[0116] determining the amount of fluorescence based on the intensity of each fluorescent pixel of the corresponding fluorescent image, wherein a fluorescent pixel is a pixel having a threshold value higher than a fluorescence threshold value; and

[0117] Dose information is determined based on the fluorescence amount.

[0118] Alternatively or additionally, processing the corresponding fluorescence image comprises:

[0119] converting pixels of the fluorescence image into a binary image based on whether each pixel is above or below a fluorescence threshold; and

[0120] Droplet boundaries of the material are determined based on the binary image.

[0121] Thus, the method may include analytically determining the amount of deposits of material on the surface. The method may include determining the size of the deposits of material on the surface. The method may include determining the average size of the deposits. Alternatively, the average size of the droplets may be known based on the method used to spray the surface with the spray composition. The method may include determining the dosage information based on the amount of deposits and / or their average size.

[0122] Selectively illuminating a surface may include illuminating the surface with a uniform illumination pattern.

[0123] All features described herein (including any accompanying claims, abstract, and drawings) and / or all steps of any method or process so disclosed may be combined with any of the above-described aspects in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. BRIEF DESCRIPTION OF THE DRAWINGS

[0124] For a better understanding of the invention and to show how embodiments of the invention may be implemented, reference is now made by way of example to the accompanying drawings, in which:

[0125] FIG1 shows the excitation and emission spectra matrix (EEM) of the following solutions: A) pH 7 leucine; B) tryptophan; C) vanillin; and D) riboflavin 5'-monophosphate sodium salt (FMN-Na);

[0126] Figure 2 Background fluorescence of various crops is shown;

[0127] Figure 3 is a graph showing fluorescent FMN-Na in solution and as a dry deposit;

[0128] Figure 4 is a graph showing how the fluorescence of FMN-Na is affected by sunlight exposure;

[0129] Figure 5 Shown is how sucrose and glycerol affect the fluorescence of FMN-Na;

[0130] Figure 6 The sunlight-induced photodegradation of FMN-Na in the presence of various compounds is shown;

[0131] Figure 7 is a graph showing the UV absorbance of FMN-Na, ascorbic acid, and sodium thiosulfate;

[0132] Figure 8 is a graph showing the effect of different concentrations of ascorbic acid and sodium thiosulfate on the photostability of FMN-Na;

[0133] Fig. 9A spray deposition fluorometer is shown;

[0134] Fig.10 A graph showing the correlation between the amount of deposits on a sample and the measured relative fluorescence units (RFU) washed off obtained from the sample is shown, with the data grouped into separate graphs according to the size of the deposits;

[0135] Fig.11 A graph showing the correlation between the volume of tracer on a slide and the percentage of coverage is shown, the deposits were produced using a spinning disk, and the samples were grouped according to the revolutions per minute (RPM) of the disk;

[0136] Fig.12 is a graph showing the correlation between the volume of the tracer on the slide and the fluorescence;

[0137] Fig.13 is a graph showing spray deposition coverage in the canopy zone of broccoli;

[0138] Fig.14 is a graph showing spray deposition coverage of the lower leaf side of strawberry plants with different wetting agents;

[0139] Fig.15A is a graph showing spray deposition coverage of leaves on apple trees before sprayer modification; and Fig. 15B is a graph showing spray deposition coverage of leaves on apple trees after sprayer modification;

[0140] Fig.16 is a block diagram of a system according to an example embodiment;

[0141] Fig.17 shows a representation of an image according to an example embodiment;

[0142] Figures 18 to 20 is a flow chart illustrating an algorithm according to an example embodiment;

[0143] Fig.21 is a block diagram of a system according to an example embodiment;

[0144] Fig. 22 is a block diagram of a light emitting device according to an example embodiment;

[0145] Fig.23 is a flowchart illustrating an algorithm according to an example embodiment; and

[0146] Fig.24 is a representation of an image according to an example embodiment. DETAILED DESCRIPTION

[0147] Example 1 - Identifying a Suitable Fluorescent Tracer

[0148] First, the inventors wanted to identify a fluorescent tracer that could be used in a method to detect and analyze the extent and thoroughness of spray deposition. Ideally, a suitable tracer would:

[0149] a) having high fluorescence quantum yield;

[0150] b) can be detected with minimal interference from background fluorescence of plants;

[0151] c) soluble in water;

[0152] d) No pH buffer is required;

[0153] e) have sufficient photostability properties;

[0154] f) is safe and acceptable for use on food crops; and

[0155] g) Cost-effective.

[0156] Initially, 140 potential compounds were identified. Taking the above factors into account, the preliminary screening left 21 possible compounds. Using CTG's HoribaAqualog to measure the excitation and emission spectrum matrix (EEM) of compounds in solution and solid phase, the solution results of four compounds in the potential compounds are shown in Figure 1. Riboflavin 5'-monophosphate sodium salt (FMN-Na), a variant of vitamin B2, was selected as a preferred compound. Specifically, riboflavin 5'-monophosphate was selected because it absorbs photons in the visible part of the electromagnetic spectrum, thereby reducing the chance of interference by other compounds that fluoresce under UV light in plant tissues. In addition, the fluorescent riboflavin 5'-monophosphate emits between 500-580nm. This is far from the absorbance and emission spectrum of chlorophyll, so the background fluorescence is reduced.

[0157] In order to make the fluorescent tracer effective, it must be compatible with widely used pesticides. Therefore, the inventor prepared the deionized water initial solution of FMN-Na, wherein FMN-Na exists with the concentration of 0.013mg / ml. The baseline fluorescence of the known pesticide solution prepared according to the label instructions was measured. Then the initial solution of FMN-Na was added to the known pesticide agent so that the resulting FMN-Na concentration of the final pesticide formulation was 0.25 μg / ml, and the fluorescence was measured again. The baseline fluorescence was subtracted to determine the amount of fluorescence produced by FMN-Na, and the fluorescence observed when it was 0.25 μg / ml with the FMN-Na concentration in deionized water was compared. The results are shown in Table 1.

[0158] Table 1 - Effects of common pesticides on riboflavin fluorescence

[0159]

[0160] Some of the pesticide products appeared to exhibit some slight fluorescence, which may have affected the results to some extent. and Both, observed fluorescence reduction greater than 100%. This may be due to these pesticides reducing or quenching the fluorescence of riboflavin, and at the same time the fluorescence of the pesticides may also be quenched due to the addition of FMN-Na, thus resulting in an overall loss of fluorescence greater than 100%.

[0161] Despite these results, it is noteworthy that the vast majority of the pesticides tested showed a reduction of less than 50% in the fluorescence of FMN-Na. This suggests that FMN-Na can be used with a wide range of pesticides.

[0162] The inventors also used a handheld imaging fluorometer to study the background fluorescence exhibited by many plants and found that Figure 2 The inventors have noted that background fluorescence is not a problem for a variety of crops and tissue types.

[0163] Therefore, FMN-Na was identified as a suitable fluorescent tracer.

[0164] Example 2 - Improving the fluorescence properties of FMN-Na

[0165] like Figure 3 and 4 As shown, FMN-Na exhibits low quantum yield and very poor photostability when dried.

[0166] like Figure 5 As shown, the inventors have found that the fluorescence properties of FMN-Na can be improved by combining FMN-Na with a gelling agent. Specifically, sucrose and glycerol were used because these compounds are safe and edible. It is worth noting that when used alone, both compounds improve the fluorescence properties of FMN-Na, but provide an exceptionally significant improvement when used in combination.

[0167] Example 3 - Improving the stability of FMN-Na

[0168] The inventors found that FMN-Na was unstable in sunlight, and neither sucrose nor glycerol improved its stability. Therefore, the inventors tested the effects of various compounds on the photodegradation of FMN-Na, and the results were Figure 6 The two most effective compounds tested were ascorbic acid and sodium thiosulfate.

[0169] Figure 7The UV absorbance spectra of FMN-Na, ascorbic acid and sodium thiosulfate are shown. It is worth noting that ascorbic acid closely matches the absorbance spectrum of riboflavin between 220 and 300nm. Without wishing to be bound by theory, it is believed that ascorbic acid prevents the photodegradation of FMN-Na by absorbing light between these wavelengths. It is worth noting that ascorbic acid is also a free radical scavenger. Therefore, this effect may also be the reason for improving the stability of FMN-Na.

[0170] In order to investigate this, the inventors prepared a tracer composition comprising the following components:

[0171] ●20g riboflavin-5'-phosphate sodium salt (food grade);

[0172] ●800g sucrose (food grade)

[0173] 0.5L glycerol (food grade); and

[0174] ●0.5L water (deionized water).

[0175] In some compositions, prior to the addition of glycerol, ascorbic acid and / or sodium thiosulfate were also added to give a concentration of 0.85 M or 1.7 M.

[0176] An additional formulation (Formulation D) was prepared by dissolving tocopherol acetate in ethanol at a weight ratio of 1:1. The ethanol solution was then added to the formulation including ascorbic acid. The amount of water in this formulation was reduced so that the total volume of the formulation was the same and the concentrations of the other components were not affected. The tocopherol compound was tested because it has been reported to interact with ascorbic acid and possibly riboflavin to reduce photodegradation processes.

[0177] All compositions were then diluted 2% (v / v) with deionized water to give the final test solutions. The concentrations of the various components in the final formulations tested are provided in Table 2.

[0178] Table 2 - Components present in the test formulations

[0179]

[0180] Figure 8 It shows how the photostability of FMN-Na varies in different formulations. Specifically, it is noteworthy that the stability of FMN-Na is significantly improved when ascorbic acid is used at a concentration of 0.85 M, and FMN-Na is essentially photostable at a concentration of 1.7 M. Interestingly, tocopherol acetate does not seem to have a beneficial effect on the photodegradation of FMN-Na.

[0181] Based on these results, the inventors developed formulations that could be used in additional testing.

[0182] In view of the results given in the above examples, the inventors developed formulations for additional testing, and the components of the formulations are given in Table 3.

[0183] Table 3 - Tracer compositions developed for additional testing

[0184] Components Amount / wt% Riboflavin-5'-phosphate sodium salt 0.99 sucrose 39.5 glycerin 31.1 Water (deionized water) 24.7 L-Ascorbic Acid 3.7

[0185] In summary, the inventors were able to identify food-safe tracers including FMN-Na. The inventors noted that the inclusion of sucrose and glycerol greatly enhanced the fluorescence of the dried sediment, and the inclusion of ascorbic acid mitigated photodegradation. The tracer is compatible with various pesticides and crops. In addition, it can be used for crops without damaging them, and is safe for humans and the environment.

[0186] Example 4 - Spray Deposition Fluorometer

[0187] The inventors have further developed a spray deposition fluorometer to allow analysis of the deposited spray. A suitable fluorometer 2 is Fig. 9 . The fluorometer 2 includes a processing and visualization module 4 coupled to a detection module 6. The detection module 6 is configured to emit electromagnetic radiation of a predetermined wavelength, which for the tracer described in Example 1 may be between 320 and 490 nm. As shown, the detection module may be focused on a plant 8 that has been pre-treated with a spray including a fluorescent tracer. The detection module 6 is also configured to detect the wavelength of the emitted light. For the experiments described below, the inventors used an emission wavelength of 470 nm and a detection wavelength of 550 nm, but it should be understood that other wavelengths may also be used.

[0188] Fig.16 1 is a block diagram of a system generally indicated by reference numeral 170 according to an exemplary embodiment. System 170 shows a surface 171 (such as a plant or leaf surface), a material 172 (such as a tracer material), a light emitting device 173, an imaging device 174, and a processor 175. Fig. 9 Check Fig.17 , surface 171 may be the surface of a plant 8 sprayed with a tracer material such as material 172. Light emitting device 173 may be included in detection module 6, and imaging device 174 and processor 175 may be included in processing and visualization module 4.

[0189] In an exemplary embodiment, light emitting device 173 is a dual wavelength light emitting device. As indicated by dashed arrow 176, light emitting device 173 illuminates surface 171 at a first wavelength and a second wavelength. As indicated by dashed arrow 177, in response to the illumination, light is received from surface 171, and imaging device 174 generates an image based on the received light. The generated image is processed at processor 175, and the processor outputs data 178. In another embodiment, light emitting device 173 is a single wavelength light emitting device.

[0190] Thus, in general, system 170 provides imaging hardware and processing algorithms. The imaging hardware provides light sources and captures images (eg, visual and fluorescent images). The processing algorithms extract information from the captured images.

[0191] In an exemplary embodiment, the light emitting device 173 illuminates the surface 171 at a first wavelength and a second wavelength. In one example, the first wavelength is in the range of 400 to 500 nm (e.g., 470 nm), and the second wavelength is in the range of 500 to 600 nm (e.g., 530 nm). In another example, the first wavelength is in the range of 465 nm to 500 nm. The light emitting device 173 may include at least one light emitting diode. Each of the at least one light emitting diode may be placed in a back focal plane of the light emitting device 173 to provide a uniform illumination pattern for illuminating the surface 171. This will be described below with reference to Fig. 22 Explain in more detail.

[0192] Fig.17 A representation of an image is shown in accordance with an example embodiment, generally indicated by reference numeral 180. Image 180 includes a first visual image 183, a first fluorescent image 184, a masked image 185, and a second fluorescent image 186. Imaging device 174 captures first visual image 183 in response to light emitting device 173 illuminating a surface (a blade in this example) with light of a visual wavelength. Imaging device 174 captures first fluorescent image 184 in response to light emitting device 173 illuminating a surface with light of a wavelength that causes material 172 to fluoresce.

[0193] In example image 180, first visual image 183 includes blade region 181 and background region 182. First fluorescent image 184 includes a fluorescent pattern. Of course, if a different surface is illuminated, region 181 will have a different form.

[0194] To determine the coverage and / or amount of material applied to a surface (e.g., a blade), only the data from the blade need be processed. Thus, the first visual image 183 is used to determine which portions of the fluorescence image should be processed. The masked image 185 includes masked regions 185a (indicating locations where fluorescence data is to be processed) and unmasked regions 185b (indicating locations where fluorescence data is not to be processed).

[0195] Second fluorescence image 186 includes treated area 186a and untreated area 186b. Thus, fluorescence data within treated area 186a can be used to determine coverage and / or dose information, as discussed further below.

[0196] As discussed further below, where the leaf region is large enough to cover the entire image 183, then it may not be necessary to generate the masked region 185a since the first and second fluorescence images will be identical.

[0197] Fig.18 is a flow chart of an algorithm generally indicated by reference numeral 190 in accordance with an example embodiment.

[0198] At step 192 of algorithm 190, a surface (such as surface 171) is illuminated, for example, by light emitting device 173. At step 194, an imaging device, such as imaging device 174, generates a first visual image (in response to illuminating surface 171 at the second wavelength), and at step 196, the imaging device generates a first fluorescent image (in response to illuminating surface 171 at the first wavelength). Finally, at step 198, a processor, such as processor 175, processes the generated images. Thus, steps 194 and 196 can be used to generate the above-mentioned images 182 and 184. Of course, steps 194 and 196 can be performed in any order, and can also be performed simultaneously.

[0199] Fig.19 is a flow chart of an algorithm generally indicated by reference numeral 200 in accordance with an example embodiment. Algorithm 200 is an example implementation of step 198 of algorithm 190.

[0200] Algorithm 200 begins at step 202, where a mask is generated (based on the first visual image generated in step 194). At step 204, a second fluorescent image is generated by masking the first fluorescent image (generated in step 196) using the mask. Fig.17 As shown, step 202 may generate a mask image 185 , and step 204 may generate a second fluorescent image 186 .

[0201] Finally, at step 206, second fluorescence image 186 is processed to determine coverage information and / or dose information for material 172. Unmasked areas of the image are omitted from the second fluorescence image so that any fluorescence detected in the background of the irradiated surface (as shown in the unmasked areas) is not included in the calculation of coverage and / or dose of the tracer.

[0202] In an example embodiment, in order to determine the coverage information and / or dose information of the material in step 206, the processor 175 processes the second fluorescent image. The processor 175 can convert the pixels of the second fluorescent image into a binary image based on whether each pixel is above or below a fluorescence threshold. For example, if the value of the pixel is below the fluorescence threshold, the binary value of the pixel is assigned to zero and the pixel is determined to be a non-fluorescent pixel; and if the value of the pixel is above the fluorescence threshold, the binary value of the pixel is assigned to one and the pixel is determined to be a fluorescent pixel. The binary image can then be used to determine the droplet boundary of the material based on the binary value of the pixel.

[0203] In one example embodiment, coverage information of material 172 is determined in step 206 based on the percentage of surface 171 covered by material 172. For example, the percentage of the surface covered by the material may be determined based on the number of fluorescent pixels as a percentage of all pixels of the second fluorescent image. As previously discussed, fluorescent pixels may be determined based on whether the pixel value of the pixel is above a fluorescent threshold.

[0204] In one example embodiment, the dose information of material 172 is determined based on the amount of fluorescence in step 206. For example, the amount of fluorescence is determined based on the intensity of each fluorescent pixel of the second fluorescent image. As previously discussed, a fluorescent pixel can be determined based on whether the pixel value of the pixel is above a fluorescence threshold.

[0205] Determination of coverage and / or amount can be used to determine the extent to which a material has been applied to a surface.

[0206] Alternative implementations of step 206 will be apparent to those skilled in the art.

[0207] Fig. 20 is a flow chart of an algorithm according to an example embodiment, generally indicated by reference numeral 210. Algorithm 210 may be used as a portion of algorithm 190 described above.

[0208] The algorithm 210 begins at step 212, where the imaging device 174 generates a plurality of candidate images of different illumination intensities. Next, at step 214, the best candidate among the candidates is selected (based on some metric). Thus, the algorithm 210 can be used to select illumination intensities in the generation of both the first visual image (in step 194) and the first fluorescent image (in step 196). In an example embodiment, three illumination intensities are provided and the most appropriate illumination intensity is selected to generate the image.

[0209] In one example, the metric used to select the best candidate in step 214 may include determining the candidate with the largest number of pixels having pixel values ​​above a first threshold (e.g., the largest number of pixels having pixel values ​​above a zero or noise threshold). Alternatively, the metric may include determining the best candidate to be the candidate with the largest number of pixels having pixel values ​​below a second threshold (e.g., the largest number of pixels below a maximum or saturation threshold).

[0210] Fig.21 is a block diagram of a system generally indicated by reference numeral 220 according to an example embodiment. System 220 is an example implementation of the arrangement of light emitting device 173 and imaging device 174 described above.

[0211] The system 220 includes a first light emitting diode (LED) module 221, a first LED 222a mounted on the first LED module, a second LED 222b (typically mounted on the first LED module, but optionally mounted on the second LED module, not shown), a first lens 223a, a second lens 223b, an excitation filter 224, a third lens 225, a sample surface 226, at least one emission filter 227, a plurality of fourth lenses 228 and a camera sensor or imaging device 229.

[0212] In an exemplary embodiment, the first LED 222a is a blue LED that emits blue light (eg, 470 nm), and the second LED 222b is a green LED that emits green light (eg, 530 nm). Fig.21 The system 220 shown in FIG. 1 is used to generate a first fluorescent image and can also be used to generate a first visual image (by illuminating a surface 226 with a second LED 222b). (It should be noted that LEDs 222a and 222b can be two of a plurality of LEDs in an array; in fact, LEDs 22a and 222b can be identical, while other LEDs in the array are the same or different from those LEDs, thereby providing a first LED and a second LED in a plurality of LEDs as required by some example embodiments.)

[0213] In an exemplary embodiment, as shown in system 220, the first LED 222a and the second LED 222b included in the LED module 221 are placed in the back focal plane of the dual wavelength light emitting device (system 220) to provide a uniform illumination pattern for illuminating the surface of the leaf or plant (i.e., the sample surface 226). Therefore, the first LED 222a and the second LED 222b can be located in the back focal plane of the lens 225 (e.g., an achromatic lens). For example, the illuminated surface can have a 1 cm 2 The irradiation area of ​​magnitude.

[0214] An image (fluorescent or visual image) of the illuminated area is formed on a camera sensor or imaging device 229. To do this, the sample can be positioned in the front focal plane of lens 225, and the light then passes through an emission filter 227 and a fourth lens 228 (e.g., a pair of achromatic lenses) to focus the image on the camera sensor or imaging device 229. The magnification of the image at the camera sensor or imaging device 229 can be selected to match the illuminated area. In this case, if the camera is smaller than the illuminated area, a reduced image may be produced.

[0215] As indicated above, lens 225 and / or fourth lens 228 may be achromatic lenses. However, this is not required for all embodiments. Other lens configurations (eg, cheaper or simpler lenses) may be selected.

[0216] Fig. 22 is a block diagram of a system generally indicated by reference numeral 230 according to an example embodiment. System 230 illustrates an LED module, such as LED module 221 described above. LED module 221 may be an LED printed circuit board (PCB) assembly.

[0217] LED module 221 includes a plurality of blue LEDs 232 (similar to first LED 222a) and a plurality of green LEDs 234 (similar to second LED 222b). Blue LEDs 232 and green LEDs 234 may be arranged alternately, as shown in system 230. In the case where LED module 221 implements the above-described LED module 221, the relative positions of the first LED and the second LED within module 221 determine whether LEDs 222a and 222b are the same or different.

[0218] Of course, many alternative arrangements of LEDs are possible.

[0219] References Figures 16 to 22 The described embodiments generally assume the use of a first light emitting device and a second light emitting device having different wavelengths. This is not necessary for all embodiments. For example, in some cases, the generation of a visual image may be omitted.

[0220] Fig.23 is a flow chart illustrating an algorithm generally indicated by reference numeral 240 in accordance with an example embodiment.

[0221] At step 242 of algorithm 240, a surface (such as surface 171 described above) is illuminated, for example, by light emitting device 173. At step 244, an imaging device, such as imaging device 174, generates a fluorescence image (in response to illuminating surface 171 at a first wavelength). At step 246, a processor, such as processor 175, processes the fluorescence image.

[0222] Fig.24 is a representation of an image indicated by reference numeral 254 in accordance with an example embodiment. Image 254 is an example of a fluorescence image that may be generated in step 244 of algorithm 240.

[0223] In example image 254, fluorescence image 184 includes a fluorescence pattern. The image pattern occupies the entire sampling area, so no masking is required, and therefore no visual image needs to be generated.

[0224] Thus, only the data of fluorescent image 254 need be processed in order to determine the coverage and / or amount of material applied to the surface of interest.

[0225] Example 5 - Calibration

[0226] The inventors tried a variety of methods to calibrate the fluorometer to allow for quantitative analysis, and these methods are described below. In each of the above experiments, the tracer formulations provided in Table 3 were diluted 2% v / v in deionized water. The diluted formulations were then sprayed onto laser-cut plastic rectangles of fixed size (9.5 mm x 7 mm) using a modified laboratory sprayer.

[0227] Laboratory sprayer uses MicronULVA (ultra-low volume atomizer) spray head to make.By controlling the flow velocity of liquid on ULVA, rotation speed and the exposure time of square and WSP, the characteristic of applied spray can be changed.The variation applied comprises the size of droplet and the quantity of droplet.For each experiment in the experiment described below, the deposit on the plastic rectangle is measured using a prototype handheld imaging fluorometer.In addition, the spray deposit on the plastic cube is washed out in 4ml deionized water, and a desktop fluorometer (Jenway 6280) is used to measure fluorescence.

[0228] 1. Calibration based on sediment quantity

[0229] The plastic rectangles were compared to water-sensitive paper cut to the same size. The plastic squares and water-sensitive paper (WSP) were placed side by side in an alternating order and then sprayed. The deposits on the WSP were analyzed using an RGB camera and the subsequent images were processed using ImageJ.

[0230] Fig.10 The correlation between the amount of deposit and the relative fluorescence units (RFU) of the washout measured is shown. The sprayed samples were separated by the size of the deposit based on the American Society of Agricultural and Biological Engineers (ASABE) S572.1 definition of droplet size classification, which is reproduced in Table 4.

[0231] Table 4 - Droplet size classification

[0232] Spray quality VMD range*(μm) Ultra-fine <60 Very thin 61-105 thin 106-235 medium 236-340 thick 341-403 Very thick 404-502 Very thick 503-665 Super thick >665

[0233] *VMD is the droplet size at which 50% of the spray volume is in droplets larger than the VMD and 50% of the volume is in droplets smaller than the VMD.

[0234] It is worth noting that while calibration of the number of deposits was achieved, the image analysis was too CPU intensive to record the number of deposits using the hardware in the handheld device. In addition, spray deposits in the field would coalesce and therefore counting the deposits would be useless. However, the analysis could be performed using a computer with a high-end CPU and could be useful in some cases.

[0235] 2. Calibration based on coverage percentage

[0236] For this experiment, the plastic cubes were grouped together based on the rotation speed of the sprayer. It was found that changing the rotation speed changed the size of the droplets, as shown in Table 5.

[0237] Table 5 - Correlation between sprayer rotation speed and droplet size

[0238] Attached photos RPM Approximate diameter of sediment (μm) 11A 1142 400-600 11B 1958 250-500 11C 4001 100-400 11D 7840 80-200 11E 12170 60-180 11F 16254 40-160

[0239] Thus, when the diameter of the deposits was approximately between 400 and 650 μm, as much as 0.06 μl of tracer was deposited on the slide and only about 25% coverage was achieved, as shown in FIG. Fig.11 A. Note that the values ​​given provide the volume of the tracer composition on the slide, not the total volume of the liquid. As explained above, the liquid on the slide is a 2% v / v solution of tracer in deionized water. Therefore, if 0.06 μl of tracer is deposited on the slide, it should be understood that this corresponds to a total volume of 3 μl of liquid that has been deposited.

[0240] at the same time, Fig.11 F shows the percent coverage for deposits between 40-160 μm in diameter. As shown, almost 100% coverage was achieved with only about 0.02-0.03 μl of tracer formulation deposited (1-1.5 μl total liquid). The reason for this difference is that larger diameter droplets are thicker than smaller droplets, thus depositing the same amount of tracer / liquid on a smaller surface area.

[0241] like Fig.11 As shown, if the size of the droplets remains constant, there is a strong correlation between the coverage percentage and the amount of tracer deposited. Therefore, if the droplet size and the coverage percentage are known, the amount of tracer deposited can be calculated.

[0242] 3. Fluorescence-based calibration

[0243] For fluorescence images, fluorescence can be measured in bit values ​​(pixel brightness). Therefore, images acquired using a handheld fluorometer were analyzed and the average bit value / mm was calculated. 2 , the result is Fig.12 As shown in the figure, the volume of the tracer measured is related to the average position value / mm 2 There is a strong correlation between them.

[0244] Fig.12 The rotation speed of the atomizer used to generate different droplets is shown, and this corresponds to the droplet size as explained above. There are slight differences in the relationship between the fluorescence value and the volume of liquid on the measured surface for the different droplet sizes. However, this difference is small and the linear relationship between the fluorescence value and the liquid volume (ignoring the droplet size) is R 2 The value was 0.72, which means that the fluorescence values ​​explained more than 70% of the tracer volume measurement.

[0245] Furthermore, if the largest droplets with an approximate diameter between 400 and 600 μm are removed, the linear relationship between the fluorescence value and the liquid volume is R 2 The value is 0.782. It is worth noting that the largest droplets are rare in agricultural spraying and usually break into smaller droplets when they hit plant surfaces.

[0246] As explained in Example 1, the degree of fluorescence will vary depending on the pesticide used. Therefore, in order to ensure accuracy, it is important to measure the fluorescence of a sample including the pesticide and the tracer. This measurement can then be used to calibrate the measurements obtained on site.

[0247] Example 6 - Working Example

[0248] The inventors worked with more than 20 growers and conducted 151 evaluations over a two-year period. These spray evaluations were conducted on 19 crop types and tested multiple spray variables. Specifically, the inventors tested the tracer composition on baby red leaf lettuce, baby leaf spinach, iceberg lettuce, red peas, beans, celery, brown onions, asparagus, sweet corn, potatoes, baby gem lettuce, cherry trees, pear trees, raspberry plants, grape vines, broccoli, strawberries, and apple trees.

[0249] Results from spray coverage analysis vary widely between crops, spray settings and conditions. High levels of spray deposit coverage are often observed on upper leaf surfaces, but very low or zero coverage is observed on lower leaf surfaces, especially at the base of the canopy. Growers have been surprised by some of the low spray coverage recorded in parts of the canopy.

[0250] Results of specific tests are provided below. In all cases, spray deposition was performed using standard industry practice. Spray deposition coverage was determined in terms of percent coverage, as described in Example 5.2.

[0251] 1. Broccoli Experiment

[0252] Spray broccoli plants with an aqueous solution including FMN-Na. Fig.13 As shown, the spray deposit coverage on the upper surface of broccoli leaves was found to be between 40% and 60%. In contrast, the coverage on the lower surface of broccoli leaves was only between 1% and 11%. The main pests of broccoli are found on the underside of the leaves.

[0253] Therefore, low coverage is considered problematic and alternative spray methods may now be investigated.

[0254] 2. Strawberry test

[0255] The inventors also evaluated the spray coverage of strawberries sprayed with three different adjuvants commonly used as "wetting agents" in horticulture. All solutions prepared included FMN-Na. The control solution did not contain any adjuvant, while the remaining solutions included commercially available wetting agents at the manufacturer's recommended concentrations.

[0256] Studies have found that the effects of wetting agents are minimal in areas with high spray coverage, such as the upper sides of leaves. Fig.14 As shown, in areas with lower coverage (e.g., undersides of leaves), the wetting agents significantly increased spray coverage. Specifically, it is noteworthy that commercially available wetting agent B doubled the coverage of the lower leaves in the bottom canopy compared to the control.

[0257] Thus, using the tracer formulations and methods described above, growers can select the best wetting agent for a given application, thereby ensuring better coverage.

[0258] 3. Apple Experiment

[0259] A Kentish apple grower has experienced severe downy mildew on his apple crop and is at risk of significant financial losses. The grower contacted an agronomist for advice, who suggested there may be a problem with the sprayer used to apply the pesticide to the apple trees. However, the grower insists the spraying is working satisfactorily.

[0260] Apple trees were planted in three-row nurseries. An aqueous solution including 2 wt% FMN-Na was applied to the apple trees using an apple grower's conventional spraying system, using the same settings and speeds that growers normally use when applying pesticides. Specifically, the sprayer was set to 400 l / ha of water. The trees were then imaged and the images analyzed as explained in Examples 3 and 4.

[0261] Analysis of the images found that the sprayers had under-sprayed the trees. Fig.15A Results of measuring spray coverage of different parts of the tree canopy over three rows of trees are shown. Spray coverage over the trees varies widely and is very low. In particular, spray coverage of trees in the inner row is shown to be particularly low, but many other areas also show spray coverage below 20%, see Fig.15A After calibrating the sprayer it was found that it was actually spraying at 370 l / ha instead of the expected 400 l / ha, which would have been one of the reasons for the low spray coverage. It is thought that a further reason for the low spray coverage and variability was at least in part due to old nozzles on the sprayer.

[0262] As a result of these results, the nozzles on the sprayer were replaced and 3 nozzle outlets were added to provide a more comprehensive spray plume. Fig. 15B As shown, spray coverage was significantly improved after the sprayer modification. In addition, the improved coverage was achieved using lower water volumes (300 l / ha), saving the grower a significant amount of money. Thanks to the sprayer modification, the grower's apple crop was saved.

[0263] in conclusion

[0264] The inventors have developed a food-safe tracer composition that is compatible with a variety of pesticides and crops. In addition, the composition can be applied to crops without damaging them and is safe for humans and the environment.

[0265] By using the composition, it is possible to determine the spray deposition achieved when applying a pesticide to plants. Advantageously, the inventors have shown that analysis of the data also allows quantification of the amount of pesticide deposited.

Claims

1. A food safety tracer composition, comprising: - a food-safe fluorescent molecule at a concentration between 0.005 wt % and 10 wt %, wherein the food-safe fluorescent molecule is riboflavin 5'-sodium monophosphate; - a stabilizer at a concentration between 0.5 wt % and 30 wt %, wherein the stabilizer is configured to increase the photostability of the food-safe fluorescent molecule, the stabilizer being sodium thiosulfate, ascorbic acid, or a combination of sodium thiosulfate and ascorbic acid, - a gelling agent at a concentration between 40% and 85% by weight, wherein the gelling agent comprises sucrose and glycerol, and the weight ratio of sucrose to glycerol is between 1:10 and 10:1; and - a solvent, wherein the solvent is water. 2 . The tracer composition according to claim 1 , wherein the concentration of the food-safe fluorescent molecule in the tracer composition is between 0.01 wt % and 1 wt %.

3. The tracer composition of claim 1, wherein the concentration of the food-safe fluorescent molecule in the tracer composition is between 0.02 wt% and 0.8 wt%.

4. The tracer composition of claim 1, wherein the concentration of the food-safe fluorescent molecule in the tracer composition is between 0.04 wt% and 0.6 wt%.

5. The tracer composition of claim 1, wherein the concentration of the food-safe fluorescent molecule in the tracer composition is between 0.06 wt% and 0.4 wt%.

6. The tracer composition of claim 1, wherein the concentration of the food-safe fluorescent molecule in the tracer composition is between 0.08 wt% and 0.2 wt%.

7. The tracer composition of claim 1, wherein the concentration of the gelling agent in the tracer composition is between 50 wt% and 80 wt%.

8. The tracer composition of claim 1, wherein the concentration of the gelling agent in the tracer composition is between 60 wt% and 77.5 wt%.

9. The tracer composition of claim 1, wherein the concentration of the gelling agent in the tracer composition is between 65 wt% and 75 wt%.

10. The tracer composition of claim 1, wherein the concentration of the gelling agent in the tracer composition is between 67.5 wt% and 72.5 wt%.

11. The tracer composition of claim 1, wherein the weight ratio of the sucrose to the glycerol is between 5:1 and 1:

5.

12. The tracer composition of claim 1, wherein the concentration of the stabilizer in the tracer composition is between 1 wt% and 10 wt%.

13. The tracer composition of claim 1, wherein the concentration of the stabilizer in the tracer composition is between 2 wt% and 7.5 wt%.

14. The tracer composition of claim 1, wherein the concentration of the stabilizer in the tracer composition is between 2.5 wt% and 5 wt%.

15. The tracer composition of claim 1, wherein the concentration of the stabilizer in the tracer composition is between 3 wt% and 4.5 wt%.

16. The tracer composition of claim 1, wherein the concentration of the stabilizer in the tracer composition is between 3.5 wt% and 4 wt%.

17. The tracer composition of claim 1, wherein the concentration of the sucrose is between 32.5 wt% and 50 wt%, the concentration of the glycerol is between 22.5 wt% and 40 wt%, and the concentration of the stabilizer is between 2 wt% and 7.5 wt%.

18. A plant protection composition comprising: - A tracer composition according to any one of claims 1 to 17; as well as - Plant protection products.

19. The plant protection composition according to claim 18, wherein the plant protection product comprises a herbicide, an insecticide, a miticide, a nematicide, a molluscicide, a bactericide and / or a fungicide.

20. The plant protection composition of claim 18, wherein the amount of the tracer composition in the plant protection composition is between 0.01% and 50% by volume.

21. The plant protection composition of claim 18, wherein the amount of the tracer composition in the plant protection composition is between 0.1% and 40% by volume.

22. The plant protection composition of claim 18, wherein the amount of the tracer composition in the plant protection composition is between 0.25% and 30% by volume.

23. The plant protection composition of claim 18, wherein the amount of the tracer composition in the plant protection composition is between 0.5% and 20% by volume.

24. The plant protection composition of claim 18, wherein the amount of the tracer composition in the plant protection composition is between 0.75% and 10% by volume.

25. The plant protection composition of claim 18, wherein the amount of the tracer composition in the plant protection composition is between 1% and 5% by volume.

26. The plant protection composition according to any one of claims 18 to 25, wherein the amount of the plant protection product in the plant protection composition is between 20% and 99.99% by volume.

27. The plant protection composition according to any one of claims 18 to 25, wherein the amount of the plant protection product in the plant protection composition is between 60% and 99.9% by volume.

28. The plant protection composition according to any one of claims 18 to 25, wherein the amount of the plant protection product in the plant protection composition is between 40% and 99.9% by volume.

29. The plant protection composition according to any one of claims 18 to 25, wherein the amount of the plant protection product in the plant protection composition is between 90% and 99% by volume.

30. The plant protection composition according to any one of claims 18 to 25, wherein the amount of the plant protection product in the plant protection composition is between 95% and 99% by volume.

31. A method comprising: selectively irradiating a surface with a first wavelength and a second wavelength, wherein the surface has a material thereon, and wherein the material is a tracer composition as defined in any one of claims 1 to 17 or a plant protection composition as defined in any one of claims 18 to 30, wherein the first wavelength is in the range of 400 to 500 nm and the second wavelength is in the range of 500 to 600 nm; generating a first fluorescent image of the surface in response to illumination at the first wavelength; generating a first visual image of the surface in response to illumination at the second wavelength; processing the first visual image to generate a mask indicating an area of ​​the first visual image; generating a second fluorescent image by masking the first fluorescent image using the mask; as well as The second fluorescent image is processed to determine coverage information and / or dose information of the material.

32. The method of claim 31 , further comprising: generating a plurality of candidate first visual images under different light intensities; as well as One of the plurality of candidate first visual images is selected as the first visual image.

33. The method of claim 31, further comprising: generating a plurality of candidate first fluorescent images under different illumination intensities; as well as One of the plurality of candidate first fluorescent images is selected as the first fluorescent image.

34. The method of claim 32 or 33, wherein the selecting selects the best candidate based on a metric.

35. The method of claim 34, wherein the metric comprises determining the candidate with the largest number of pixels having pixel values ​​above a first threshold and / or the candidate with the largest number of pixels having pixel values ​​below a second threshold.

36. The method of claim 31 , wherein the first wavelength is in the range of 465 nm to 500 nm.

37. The method of claim 31 , wherein determining coverage information comprises determining a percentage of the surface that is covered by the material.

38. The method of claim 37, wherein determining the percentage of the surface covered by the material comprises determining the number of fluorescent pixels as a percentage of all pixels of the corresponding fluorescent image, wherein fluorescent pixels are pixels having a pixel value above a fluorescence threshold.

39. The method of claim 31 , wherein determining the dosage information comprises: determining the amount of fluorescence based on the intensity of each fluorescent pixel of the corresponding fluorescent image, wherein a fluorescent pixel is a pixel having a threshold value above a fluorescence threshold value; as well as Dose information is determined based on the fluorescence amount.

40. The method of claim 31 , wherein processing the corresponding fluorescent image comprises: converting pixels of the fluorescence image into a binary image based on whether each pixel is above or below a fluorescence threshold; as well as Droplet boundaries of the material are determined based on the binary image.

41. The method of claim 31 , wherein selectively illuminating the surface comprises illuminating the surface with a uniform illumination pattern.

42. The method of claim 31 , wherein the surface comprises a plant or a portion thereof.

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