Use of tall oil fatty acids as phytosanitary adjuvants

Abstract

The present invention pertains to the agricultural field, and particularly to the use of tall oil fatty acids as a phytosanitary adjuvant, particularly for preventing spray drift. The present inventors have indeed shown that the introduction of tall oil fatty acids into phytosanitary compositions allows increasing droplet size distribution upon spraying and therefore reducing off-target spraying. The present invention therefore provides methods for generating droplets, treating plants and for preventing spray drift. The invention also relates to phytosanitary compositions comprising tall oil fatty acids.

Description

DescriptionTitle: USE OF TALL OIL FATTY ACIDS AS PHYTOSANITARY ADJUVANTS Technical Field

[0001] The present invention pertains to the field of phytosanitary treatments and particularly to the formulation of phytosanitary adjuvants. The invention particularly aims at providing phytosanitary adjuvants for increasing droplet size distribution and preventing spray drift upon treatment of plants.Background Art

[0002] The application of phytosanitary products, such as herbicides, insecticides, and fungicides, is a critical component of modern agricultural practices. These products are essential for protecting crops from pests and diseases, thereby ensuring high yields and quality produce.

[0003] However, the effectiveness of these products can be significantly compromised by the phenomenon of spray drift. Spray drift occurs when droplets of the phytosanitary product are carried away from the target area by wind or air currents during application. This not only reduces the efficacy of the treatment but also poses environmental risks, such as contamination of non-target areas, including water bodies, neighboring crops, and residential zones.

[0004] To mitigate the issue of spray drift, various strategies have been employed, including the use of specialized nozzles, adjustments in application techniques, and the incorporation of adjuvants into the spray formulations.

[0005] Adjuvants are substances added to phytosanitary products to enhance their performance. Among the different types of adjuvants, anti-drift adjuvants are specifically designed to reduce the drift potential of spray droplets by modifying their physical properties, such as size and / or weight.

[0006] Despite the availability of existing anti-drift adjuvants, there remains a need for improved formulations that offer enhanced drift reduction while maintaining or improving the efficacy of the phytosanitary product.

[0007] Current formulations often face challenges such as limited compatibility with a wide range of active ingredients, potential phytotoxicity, and environmental concerns. Furthermore, the increasing awareness of environmental sustainability and the adverse effects of synthetic chemicals on human health and ecosystems have driven the demand for natural products having limited impacts on the environment.

[0008] There is thus a need for new eco-friendly phytosanitary adjuvants that would allow preventing the phenomenon of spray drift upon treatment of plants.Summary

[0009] The invention is defined by the claims.

[0010] Surprisingly, the present inventors have shown that it is possible to formulate anti-drift adjuvants by using tall oil fatty acids (TOFA). The inventors have particularly shown that the introduction of TOFA in phytosanitary compositions allows increasing droplet size distribution uponspraying, thereby reducing the risk of droplet drifting. TOFA are natural compounds that are issued from paper mill waste. Recycling this waste as raw material for adjuvant formulations not only allows reducing the environmental impact of paper mill but also allows obtaining a 100% biobased sustainable solution.

[0011] Therefore, the present invention generally pertains to the use of tall oil fatty acids as a phytosanitary adjuvant, in particular to prevent and / or reduce spray drift upon application of a phytosanitary composition to a plant.

[0012] The present invention further provides a method for generating droplets comprising a step of spraying a composition comprising tall oil fatty acids.

[0013] The invention also relates to a phytosanitary adjuvant and a phytosanitary composition comprising tall oil fatty acids and a surfactant.

[0014] According to a further embodiment, the invention also provides a method for treating a plant with a phytosanitary product, wherein said method comprises mixing said phytosanitary product with tall oil fatty acids and applying said mixture to a plant.

[0015] Finally, the present invention also pertains to a method for preventing spray drift upon application of a phytosanitary composition on a plant, wherein said method comprises adding tall oil fatty acids to said composition prior application.Brief Description of the figures

[0016] [Fig. 1]: Measuring procedure.

[0017] [Fig. 2]: Example of controlled spiked tank mix onto plastic discs to assess percentage recovery and storage stability

[0018] [Fig. 3]: Layout of experimental equipment in wind tunnel

[0019] Fig. 4]: Total % drift reduction at 2.5 bar pressure, for each tank mix. Compared to reference nozzle at 2.5 bar pressure. Application rate 150 L / ha for all treatments

[0020] Detailed description of the invention

[0021] The present invention pertains to the use of tall oil fatty acids (TOFA) as a phytosanitary adjuvant, more particularly to prevent and / or reduce spray drift upon application of a phytosanitary composition to a plant.

[0022] “Tall oil fatty acids” or “TOFA” are a byproduct derived from the processing of pine trees, specifically from the kraft pulping process used in the paper industry. During this process, wood chips are cooked with chemicals to separate the cellulose fibers, and a byproduct known as "tall oil" is produced. This crude tall oil is then further refined to extract the fatty acids. TOFA primarily consists of a mixture of unsaturated fatty acids, such as oleic acid and linoleic acid, along with some saturated fatty acids like palmitic acid and stearic acid. These fatty acids are valuable in various industrial applications due to their chemical properties. They are used in the production of soaps, detergents,coatings, adhesives, and as intermediates in the synthesis of other chemicals. Additionally, TOFA can be used as a raw material in the production of biofuels and lubricants. TOFA can be easily obtained from specialized manufacturers. In the context of the present invention, the TOFA used can e.g. be the TOFA commercialized by DRT (France) under reference RESINOLINE® BD 2 (having CAS® registry No. 61790-12-3) or under reference RESINOLINE® BD 30 (having CAS® registry No. 8002-26-4). Reference “BD2” comprises TOFA only whereas reference “BD30” further comprises a small amount of resin acids.

[0023] In the context of the present invention, the “plant” can be any living being belonging to the plant kingdom, whether cultivated or not. The plant is a terrestrial plant. It can be a woody plant or an herbaceous plant. The plant can typically be crops:

[0024] - field crop plants are typically selected from peanuts, spring and winter oats, fodder and industrial beets, soft winter and spring wheat, durum wheat, bromegrass, orchard grass, spelt, fescue, timothy, grain, forage and silage maize, millet, miscanthus, moha forage and grain, spring and winter barley, panic grass, English and Italian ryegrass, rice, spring and winter rye, sorghum, switchgrass, spring and winter triticale, spring and winter camelina, hemp, winter and spring rapeseed, canola, spring and winter white and brown mustard, turnip rape, pastel, spring and winter fava bean, bird’s-foot trefoil, lupin, alfalfa, spring and winter peas, forage and protein peas, sainfoin, soybeans, white, red and red clover, vetch, hops, buckwheat, spring and winter flax (oilseed and textile), tobacco and sunflower;

[0025] - plants grown in fallow are typically selected from English and Italian ryegrass, Persian clover, white mustard, phacelia, white, red or purple clover and vetch;

[0026] - vegetable crops are typically selected from garlic, dill, artichoke, asparagus, eggplant, beet, broccoli, cardoon, carrot, celery root and stalk, tuberous chervil, chicory, Chinese cabbage, Brussels sprouts, leafy cabbage, head cabbage, cauliflower, kohlrabi, watercress, cucumber, gherkins, zucchini, melon, watermelon, pumpkin, shallot, spinach, fennel, fava bean, flageolet, strawberry, beans, lettuce, dry and fresh lentils, maize, turnip, cowpea, onion, parsley, chili, leek, peas, bell pepper, potato, purslane, radish, horseradish, rhubarb, arugula, rutabaga, salsify, curly endive, black salsify, tomato and Jerusalem artichoke;

[0027] - fruit crops such as lemon, clementine, lime, mandarin, orange, grapefruit, quince, fig, almond, chestnut, hazelnut, walnut, apricot, cherry, jujube, cherry-plum, nectarine, peach, plum, kiwi, nashi, medlar, olive, cranberry, black currant, rose hip, raspberry and other Rubus, currant, blackberry, blueberry, black elder, pear and apple;

[0028] - seed-bearing crops are typically selected from beet, brome, cocksfoot, fescue, ryegrass, seed-bearing forage legumes, seed-bearing umbellifers, seed fennel, seed bean, seed lupin, seed trefoil, seed alfalfa, seed maize, hemp, flax, chrysanthemum, bitter apple, wallflower, carnation, pansy, sweet pea, queen daisy, hollyhock, beet, carrot, celery, annual and biennial chicory, cabbage, chives, cucurbits, shallot, spinach, beans, lettuce, lamb’s lettuce, turnips, onions, parsnips, parsley, leeks, peas, chickpeas, radishes, arugula, dill, chervil, coriander and clover;

[0029] - plants cultivated in ornamental crops are typically selected from conifers, broad-leaved trees, elms, lilies, Hippeastrum, narcissus, nerine, iris, hyacinth, lily, lily of the valley, gladiola, hydrangea, carnation, pale iris, palm, pelargonium, roses, tulips and other floral species; - plants cultivated in tropical crops are typically pineapple and other anacardiaceous, avocado, banana, sugar cane, passion fruit, Chinese cabbage, cassava, sweet potato, yam, mango and papaya;- plants grown for viticulture such as wine or table grapes (including the various species of vines); and- plants cultivated for aromatic, perfume or medicinal purposes are typically selected from wormwood, yarrow, mugwort, costmary, burdock, dill, Roman chamomile, spices, angelica, basil, caraway, chervil, chives tarragon, bay leaves, rosemary, mint, parsley, sage, gentian, lavender and lavandin, lovage, evening primrose, oregano, borage, poppy seed, safflower, goosefoot, squash, castor oil, sesame, savory, marigold and thyme.

[0030] The “plant” in accordance with the invention may be selected from any of the crop species listed above, and particularly from the different varieties of these species.

[0031] “Phytosanitary adjuvants”, also referred to as tank-mix additives, are formulations that are mixed with phytosanitary products such as herbicides, insecticides, fungicides or fertilizers, to enhance their performance and effectiveness. Phytosanitary adjuvants do not have an effect on the plant as such, they are designed to improve the physicochemical properties of the phytosanitary product. They can e.g. be used for improving spray coverage, reducing spray drift, enhancing penetration, increasing adhesion and retention of the phytosanitary product, improving the compatibility of the components of the phytosanitary product, enhance their stability, or reduce evaporation. Usual phytosanitary adjuvants include e.g. carboxymethyl cellulose, glycerol, sugars (monosaccharides such as glucose, galactose, fructose; oligosaccharides and polysaccharides such as sucrose, lactose, maltose or trehalose), glycerol, ferric EDTA, gum arabic and mineral and organic oils.

[0032] “Anti-drift adjuvants” are formulations that are designed to optimize droplet size and distribution, thereby minimizing spray drift and maximizing on-target deposition.

[0033] “Spray drift” refers to the movement of phytosanitary compositions spray droplets away from the intended target area during or after application. This phenomenon occurs when droplets are carried by wind or air currents, leading to unintended deposition on off-target areas such as neighboring crops, water bodies, residential zones, or natural habitats. Spray drift can significantly reduce the efficacy of the pesticide application, as less of the product reaches the target pests or plants. Additionally, it poses environmental and health risks by potentially contaminating sensitive areas and affecting non-target organisms. Factors influencing spray drift include droplet size, wind speed and direction, temperature, humidity, and the height and speed of the application equipment. To mitigate spray drift, various strategies can be employed, such as using drift-reducing nozzles, adjusting application techniques, and increasing droplet size distribution. Spray drift can be detected and quantified by checking the quantity of phytosanitary composition sprayed on off-target areas.Techniques commonly used for detecting / monitoring spray drift include e.g. collecting samples on the treated zone and surrounding areas, adding tracer dyes or fluorescent tracers to the composition, or using techniques such as LIDAR (Light Detection and Ranging) or infrared imaging to detect and measure spray drift in real-time, providing spatial and temporal data on droplet movement.

[0034] The use of TOFA allows preventing or reducing spray drift upon application of a phytosanitary composition to a plant.

[0035] The expression “preventing or reducing” spray drift indicates that the use of tall oil fatty acids according to the present invention allows completely (in the case of preventing) or partially (in the case of reducing) inhibiting the movement of spray droplets away from the intended target area observed during or after application of a phytosanitary composition comprising said TOFA, when compared to the movement of spray droplets observed during or after application of a control phytosanitary composition which does not comprise TOFA or of a control composition consisting essentially of water (e.g. tap water).

[0036] A “phytosanitary composition” is a formulation designed to protect plants from pests, diseases, and other harmful organisms, and / or to provide elements aiming at helping / improving their growth (such as fertilizers). Phytosanitary compositions include a “phytosanitary product” (i.e. an active ingredient) which can e.g. be selected from fertilizers, herbicides, insecticides, fungicides, or other biocides that target specific pests or pathogens, as well as one or more phytosanitary adjuvant. In the context of the present invention, said phytosanitary product can be any biocontrol product for which drift reduction might be considered as advantageous or necessary. The phytosanitary product can be any compound usually used as an active ingredient in phytosanitary compositions, such as herbicides including glyphosate, atrazine, 2,4-D, dicamba and paraquat; insecticides including imidacloprid, chlorpyrifos, permethrin, Spinosad and Bacillus thuringiensis (Bt); fungicides including mancozeb, chlorothalonil, copper sulfate, azoxystrobin and propiconazole; bactericides including streptomycin and copper hydroxide; nematicides including oxamyl or fosthiazate; or fertilizers including nitrogen-based fertilizers (such as urea, ammonium nitrate and ammonium sulfate), phosphorus-based fertilizers (such as monoammonium phosphate, diammonium phosphate and superphosphate), potassium-based fertilizers (such as muriate of potash, potassium sulfate and potassium nitrate), micronutrient fertilizers (such as zinc sulfate, iron chelates and copper sulfate) and calcium and magnesium fertilizers (such as calcium nitrate and dolomite).

[0037] The primary goal of a phytosanitary composition is to ensure the health and productivity of crops by effectively managing pest populations, preventing disease outbreaks and to stimulate plant growth. Phytosanitary compositions can be applied to plants by means of various techniques, including:

[0038] - Spraying (also referred to as foliar spraying) : it is the most common method. It involves applying the formulation directly to the leaves and stems of plants using spray equipment.

[0039] - Soil Application: the formulation is applied directly to the soil, either as a liquid drench or in granular form.

[0040] - Seed Treatment: seeds are coated or soaked with the phytosanitary composition before planting.

[0041] - Drip Irrigation: the phytosanitary composition is delivered through the irrigation system, allowing for precise application to the root zone.

[0042] - Granular Application: the phytosanitary composition is applied in the form of a granular formulation that is spread over the soil surface, either manually or with mechanical spreaders. They are often used for soil-applied insecticides and fertilizers.

[0043] - Injection: the phytosanitary composition is injected directly into the plant or soil, providing targeted treatment for specific pests or diseases.

[0044] In the context of the present invention, the phytosanitary composition comprising TFOA as phytosanitary adjuvant is applied to the plant by spraying. This method is well-known by the skilled person. It involves using spray equipment which acts by dispersing the phytosanitary composition into droplets. Spray equipment comprises a tank to store the phytosanitary composition, a pump (such as diaphragm, piston, or centrifugal pumps) to pressurize the composition and forcing it through the system, a pressure regulator, nozzles (which atomize the liquid into droplets) and hoses and pipes (to transport the pressurized liquid from the tank to the nozzles). The droplets sprayed then cover the plant, thereby allowing for the absorption of the active ingredient comprised in the phytosanitary composition by the plant.

[0045] As explained above, the present inventors have shown that the introduction of TOFA in a composition allows increasing droplet size distribution of said composition upon spraying.

[0046] Accordingly, an aspect of the present invention provides a method for generating droplets comprising a step of spraying a composition comprising TOFA. Spraying is performed as described above, by means that are well known to the skilled person, e.g. by using spray equipment.

[0047] Droplets generated by spraying a composition comprising TOFA therefore show a size distribution that is higher than that of the same composition withoutTOFA. In particular, in the context of the present invention, droplets generated by using a flat-fan nozzle (such as the "Teejet 110-02 VK" flat-fan nozzle used in the experimental section below) at a nominal pressure of 2 to 3 bars have a mean size of more than 100pm, more particularly of more than 105 pm. More particularly, the droplets thereby generated have a low span (which represents the droplets’ size distribution’s spread), i.e. a span below 0,70, more particularly below 0,67. Droplet size distribution can be easily determined by means of various methods such as high-speed imaging, laser diffraction, phase doppler particle analysis (PDPA), optical particle counters, interferometric laser imaging for droplet sizing (ILIDS), acoustic methods, spray pattern analyzers or gravimetric analysis. Droplet size distribution can advantageously be determined by high-speed imaging as described in the experimental section below. In this context, droplet size distribution is presented as of cumulative volumetric distributions of droplets between 50 and 500 pm in diameter. The common reduced parameters used to characterize droplet size distributions are calculated: the volumetric median diameter (VMD or DV50, i.e. droplet diameter at which 50% of the total volume of spray is smallerand 50% is larger.), DV10 (droplet diameter at which 10% of the total volume of spray is smaller), DV90 (droplet diameter at which 90% of the total volume of spray is smaller), the span (span is used to describe the width or breadth of the particle size distribution. It provides a measure of the distribution's spread, indicating how narrow or wide the range of particle sizes is. A low span value indicates a narrow particle size distribution, meaning the particles are relatively uniform in size. A high span value indicates a wide particle size distribution, meaning there is a greater variation in particle sizes) of the distribution and the percentage of the spray volume composed of droplets having a diameter less than 100pm (V100).

[0048] In the context of the present invention, the TOFA are advantageously comprised in the composition at a concentration comprised between 200 and 900 g / L, preferably 300 and 800g / L, more preferably between 400 and 600 g / L.

[0049] According to a specific embodiment, the composition can comprise from 25 to 90%, preferably from 45 to 70%, more preferably from 50 to 60% by weight of TOFA relative to the total weight of the composition.

[0050] In the context of the present invention, the composition can advantageously comprise a surfactant.

[0051] As used herein, the term "surfactant" refers to a natural or synthetic amphiphilic compound. A surfactant can be non-ionic, zwitterionic, or ionic (including anionic and cationic surfactants). The phytosanitary composition comprises one or more surfactants selected from non-ionic, zwitterionic, cationic, anionic surfactants and mixture thereof.

[0052] Examples of non-ionic surfactants include e.g. alkyl polyglucosides (APGs), ethoxylated alcohols, vegetable oil ethoxylates (VOEs) such as ethoxylated rapeseed oil, sorbitan esters including ethoxylated sorbitan esters, polyoxyethylene (POE) esters, block copolymers of ethylene oxide and propylene oxide, fatty acid ethoxylates, amine ethoxylates, silicone-based surfactants and polyethylene glycol (PEG) esters and ethers (such as Levenol® PEG ethers, including PEG glyceryl cocoate).

[0053] Examples of zwitterionic surfactants include e.g. cocamidopropyl betaine (CAPB), lauryl betaine, cocamidopropyl hydroxysultaine, lauryl hydroxysultaine, dodecyl dimethylamine oxide, cocamidopropylamine oxide and sulfobetaine surfactants.

[0054] Examples of ionic surfactants include e.g. sodium lauryl sulfate (SLS), sodium dodecylbenzenesulfonate, sodium dioctyl sulfosuccinate, alkyl aryl sulfonates, cetyl trimethyl ammonium bromide (CTAB), benzalkonium chloride and dodecyl trimethyl ammonium chloride.

[0055] According to a specific embodiment, the composition can comprise from 10 to 35%, preferably from 15 to 30%, more preferably from 20 to 25% by weight of surfactant relative to the total weight of the composition.

[0056] In the context of the present invention, the composition can further comprise a terpene alcohol. Terpene alcohols can particularly be used for preventing rebound effects upon spraying of the formulation.

[0057] “Terpene alcohol” refers to a group of compounds referred to as “terpenoids”, i.e. terpenes modified with one or more hydroxy groups. In other words, terpene alcohol will be understood by a person of ordinary skill in the art as encompassing primary, secondary, and tertiary alcohol derivatives of terpenes. T erpenes are chemical compounds that are widespread in nature, mainly in plants as constituents of essential oils. Their building block is the hydrocarbon isoprene (C5H8)n with n an integer ranging from 1 to 8. Terpenes are called monoterpenes (C10) when n equals 2, sesquiterpenes (C15) when n equals 3, or diterpenes (C20) when n equals 4. Some well-known examples of terpene alcohol include e.g. dihydromyrcenol (DHM), geraniol, linalool, terpineol, citronellol, nerol, myrcenol, lavandulol, farnesol, nerolidol, bisabolol, cubelol, menthanol, menthol and retinol. All these compounds are well-known to the skilled person who can easily obtain them from specialized manufacturers or from various natural sources such as plants. The composition according to the present invention can comprise one terpene alcohol or a combination of two terpene alcohols or more.

[0058] When a terpene alcohol is present, the composition can comprise from 0,1 to 20%, preferably from 5 to 15%, more preferably from 7 to 10% by weight of terpene alcohol relative to the total weight of the composition.

[0059] In the context of the present invention, the composition can further comprise one or more compound commonly used in the formulation of phytosanitary adjuvants, such as e.g. oils (including mineral oils, vegetable oils or methylated seed oils), stickers (including latex polymers or pinolene), penetrants (including organosilicone compounds and D-limonene), buffers and acidifiers (including glycerol and propylene glycol), compatibility agents (such as lecithin) and foam suppressants (such as silicone-based antifoams).

[0060] According to a specific embodiment, the composition comprises an oil, preferably a methylated seed oil such as rapeseed methyl ester. According to this specific embodiment, the composition can comprise from 0,1 to 20%, preferably from 5 to 15%, more preferably from 7 to 10% by weight of oil relative to the total weight of the composition.

[0061] The composition can be incorporated in an aqueous composition, i.e. a composition comprising water as a solvent. In this context, the aqueous composition can comprise from 0,1 to 2%, preferably from 0,2 to 1%, more preferably from 0,25 to 0,5% by weight of phytosanitary adjuvant relative to the total weight of the aqueous composition.

[0062] The phytosanitary adjuvant is typically applied to plants in an amount comprised between 0,1 and 5L / ha, more preferably between 0,2 and 2L / ha.

[0063] A further embodiment of the present invention pertains to a phytosanitary adjuvant comprising TOFA and a surfactant, and optionally a terpene alcohol. The present invention also pertains to a phytosanitary composition comprising such a phytosanitary adjuvant and a phytosanitary product.All the features described above regarding the composition described in relation with the uses and method above apply.

[0064] This phytosanitary adjuvant and phytosanitary composition can typically be in the form of droplets, i.e. in the form obtained after spraying. Droplets are spherical or nearly spherical particles of liquid that are formed upon dispersion, e.g. by spraying, into the air. They can vary in size from microscopic to several millimeters in diameter. In the context of the present invention, more than 99%, more preferably more than 99,2% of the droplets formed with the phytosanitary adjuvant or composition (e.g. when sprayed by using a flat-fan nozzle) have a diameter greater than 100pm as determined by the high-speed imaging method as described in the experimental section below.

[0065] As described above, the present invention provides TOFA as phytosanitary adjuvants.

[0066] Therefore, the present invention further provides a method for treating a plant with a phytosanitary product, wherein said method comprises mixing said phytosanitary product with tall oil fatty acids and applying said mixture to a plant by spraying.

[0067] The present invention also pertains to a method for preventing spray drift upon application of a phytosanitary composition on a plant, wherein said method comprises adding tall oil fatty acids (TOFA) to said composition prior application.

[0068] All the features described above regarding the compositions, uses and method above apply.

[0069] The invention will now be further illustrated by means of the following examples.Examples

[0070] Example 1 - droplet size distributionn

[0071] Goal of the study

[0072] The aim of the study is to establish the droplet size distribution from an agricultural flat-fan nozzle for different tank-mix spray solutions with a non-intrusive high-speed imaging-based method. The droplet size distribution is presented as of cumulative volumetric distributions of droplets between 50 and 500 pm in diameter. The common reduced parameters used to characterize droplet size distributions will be calculated: the volumetric median diameter (VMD or DV50, i.e. droplet diameter at which 50% of the total volume of spray is smaller and 50% is larger.), DV10 (droplet diameter at which 10% of the total volume of spray is smaller), DV90 (droplet diameter at which 90% of the total volume of spray is smaller), the span (span is used to describe the width or breadth of the particle size distribution. It provides a measure of the distribution's spread, indicating how narrow or wide the range of particle sizes is. A low span value indicates a narrow particle size distribution, meaning the particles are relatively uniform in size. A high span value indicates a wide particle size distribution, meaning there is a greater variation in particle sizes) of the distribution and the percentage of the spray volume composed of droplets having a diameter less than 100pm (V100).

[0073] Spray application bench

[0074] The tests were carried out using a "Teejet 110-02 VK" flat-fan nozzle at a nominal pressure of 2.5 bars, at 50 cm below the nozzle output. The nozzle is moved along the measuring lines (Figure 1) during the droplet size measurement so as to obtain a representative assessment of the entire spray. By its symmetry (Figure 1), a quarter of the jet is investigated by making 8 transects evenly spaced perpendicular to the optical axis. According to a section, the measurements are carried out at a fixed camera frequency for a constant nozzle displacement speed.

[0075] Measuring principle

[0076] The measuring device consists of a high-speed camera combined with a backlighting consisting of multiple light emitting diodes (LED). The sampling volume in which droplets are measured is located between the camera and the light, the shadow of droplets being projected on the camera sensor (shadowgraphy). At each acquisition, two images are recorded in a very short timeframe. Each image pair is processed using advanced image analysis algorithms that derive the diameter as well as the vertical and horizontal components of the velocity of each droplet. Then the droplet size distribution is calculated by gathering the data from all the pairs of recorded images. Finally, a size correction is applied to the distribution to switch from a volumetric measurement to a flux measurement. The measurement method is detailed by De Cock et. al. (2016).

[0077] Number of trials

[0078] Each assay is made up of 3 repetitions to derive the statistical parameters of the droplet size distributions. One assay corresponds to an additive at a given concentration.

[0079] [Table 1]: Details of the test performed.

[0080] RESULTS

[0081] The results of the five assays are presented in Table 2 below following the image analysis procedure described above.

[0082] Table 2 shows the DV10, DV50, DV90, span of the droplet size distribution and the V100 for each test. The span is calculated as follows: span = (DV90-DV10) / (DV50).

[0083] The V100 corresponds to the percentage of the spray volume having a diameter of less than 100 pm and is an important explanatory factor for spray drift reduction properties.

[0084] [Table 2]: Main parameters of the droplet size distributions for each assay.

[0085] Overall, all the additives tested in this study increased the size of the droplets, compared to tap water.

[0086] The DV50, a parameter commonly used to describe the mean size of the droplets, is increased by 9 to 10% for assays 1, 3 and 4 (tap water + Solution A, tap water + Solution C and tap water + LI 700® STAR). It is increased by 5% for assay 2 (tap water + Solution B). The DV10 and DV90 follow the same increasing trend.

[0087] The span of the droplet size distribution is reduced by 7% compared to the tap water for assay 1 (tap water + Solution C), by 3% for assay 2 (tap water + Solution B), by 5% for assay 3 (tap water + Solution C) and by 4% for assay 4 (tap water + LI 700® STAR).

[0088] The volume proportion of droplets having a diameter of less than 100 pm is 1.63% for tap water (without adjuvant), and it ranges between 0.70% and 0.94% for the four assays with adjuvants.

[0089] CONCLUSIONS:

[0090] The objective of this study is to quantify the effect of tank-mix additives in tap water on the diameter of the droplets produced by flat-fan agricultural nozzles. To do this, a non-intrusive high-speed imaging methodology is employed. The influence of each additive in terms of droplet size is presented in this report (Table 2), compared to tap water and LI 700® STAR (marketed anti-drift reference reference). An increase in the size of the droplets is observed depending on the spray solutions at the concentration tested.

[0091] Even if there are slight differences between results obtained for Solution B, Solution A and LI700® STAR, the effect of these 3 adjuvants on the droplet size and on the droplet size distribution are quite similar (Table 2).

[0092] Solution B, Solution A are both based on tall oil fatty acid.

[0093] Formulas based on tall oil fatty acid behave in a way that is close to the market target and have bigger droplets.

[0094] Formulation framework for a tall oil fatty acid-based anti-drift adjuvant, which increases droplet size compared to tap water. The hypothesis is that if the droplet size increases, the droplet drifts less in the wind.

[0095] 1 -Economical because it is used at low concentration, only 0.25% of the additive is sufficient to significantly modify the drop spectra compared with tap water.

[0096] 2-Adaptable to all types of equipment and can be combined with drift reduction nozzles for an additional effect

[0097] 3- Ecofriendly ingredient as it comes from the recycling of paper mill waste.

[0098] Example 2 - Spray drift measurement

[0099] Goal of the study

[0100] The properties of a spray liquid can have a significant effect on the formation of spray by nozzles, leading to changes in the potential for spray drift. Tank mix additives have been developed by the chemical industry specifically for achieving drift reduction, and other adjuvants, developed to provide benefits such as improved retention, spreading or plant uptake, have also been shown to contribute to drift reduction. The challenge of using the drift-reduction potential of adjuvants or co-formulants is that the degree to which this can be achieved depends upon both nozzle and product, and therefore a significant amount of data is needed to enable reliable assessments to be made.

[0101] The aim of this study is to establish the spray drift from an agricultural flat-fan nozzle for different tank-mix spray solutions in the Silsoe Spray Applications Unit Ltd wind tunnel.

[0102] Tracer compatibility

[0103] The compatibility of the water-soluble Green S tracer was first assessed for each tank mix combination to confirm that detection and accurate quantification was achievable without interference in the presence of all tank mix components. A standard regression was prepared from each tank mix and the absorbances measured by spectrophotometry max of 634nm. These values were compared against a reference of 0.1% Green S in water.

[0104] The second stage of validation was to determine the percentage recovery of the deposited formulation from a surface. Polythene discs were used to simulate the surface of the polythene line collectors used in the wind tunnel study.

[0105] Three replicate spikes of 5, 10 and 50 L aliquots of each tank mix (Table 3), were pipetted onto plastic discs and left for 2 hours to dry (Figure 2). The spiked discs were covered to prevent light degradation during the drying period. After 2 hours, each disc was extracted into 10 mL of deionised water and shaken on a flatbed shaker for a nominal 20 mins. The extracted solutions were then quantified by spectrophotometry.[Table 3]: Details of products testedDrift measurementsMeasurements were made of the airborne spray profiles downwind of the nozzle mounted in the wind tunnel at SSAU, the layout of which is shown in Figure 3. The nozzle was mounted 0.6 m above the floor of the tunnel, simulating operation on a boom sprayer with a nozzle height of 0.5 m above the target.The nozzle was operated with a spray liquid delivered from a pressurised canister giving accurate control of pressure, measured at the nozzle, for the prepared tank mixes (Table 4). The selected nozzle is XR 11002 VP, the pressure and transporter speed are respectively 2.5bar and 1.611m / s. Airborne spray profiles were determined using 1.98 mm diameter polythene, passive sampling lines, mounted horizontally on frames, along the tunnel to determine, a horizontal profile. The lines were mounted at 0.1 m above the floor, at distances from 2.0 to 7.0 m downwind of the nozzle with a spacing of 1.0 m (as for a standard UK LERAP test).Spray deposited on sampling lines were recovered into a known volume of water. The solutions were quantified by spectrophotometry using a reference curve, prepared from the tank mix liquid.[Table 4]: Tank mixed used in the wind tunnel experimentsRESULTSTracer compatibilityDetails of the product tested are given in Table 3. The compatibility tests for the tank mixes when mixed with 0.1% Green S tracer, indicated that the quantity of the tracer could be accurately measured in the presence of all tested products.The 0.1% Green S (E142) tracer calibration curves prepared with and without the herbicides and adjuvant present, indicated good agreement across the concentration range measured.The mean recoveries of the spiked material, on the plastic surfaces, with and without the herbicides and adjuvant, were between 99.2 - 100.8%. indicating that they were within acceptable limits. These two tests indicate that there were no interactions between the herbicides, adjuvant, and the tracer inhibiting the detection of the tracer, for the concentrations of constituents used. In addition, there were no interactions between the tank mixes and the target material which was confirmed by the percentage recoveries (Table 5).The storage stability of the tank mixes, deposits on targets and extracted solutions was confirmed to remain unchanged, over a 4-day period at 6-8°C, in the dark.[Table 5]: Percentage recovery of spiked tank mixes from plastic collector surface>Wind tunnel drift measurementsThe average value for spray liquid deposited on collecting lines at distances between 2.0 and 7.0m downwind are shown in Table 6.Table 7 shows the value for drift reduction at each measured distance, and averaged over all distances, achieved by the products and doses in the tank mixes.Each assay is made up of 3 repetitions.[Table 6]: Mean volume of spray liquid (pL) recovered from collecting, for the tank mixes for the TeeJet XR 11002 nozzle operated at 2.5 bar delivering 150 L / ha>[Table 7]: Mean % Drift reduction at each distance downwind, referenced against XR 110 02 VP, operated at 2.5 bar, delivering 150 L / ha, spraying water onlyDiscussionAll products could be accurately measured in the presence of the nominated tracer confirming that there were no compatibility issues. Percentage recoveries from the target material were acceptable indicating no matrix binding effects and all samples were stable for the duration of the experiment. The total percentage drift reduction values for each tank mix (150 L / ha at 2.5 bar) using a XR 11002 VP nozzle have been compared to water (150 L / ha at 2.5 bar pressure) using the reference nozzle XR 110 02 VP in Table 7, at distances between 2.0 m and 7.0 m. The data presented in Figure 4 enables comparison across all treatments. The trend indicates that increasing the dose of SolutionB results in an increase in drift reduction, while increasing the dose of Solution D does not change the drift reduction provided by the product for the doses tested. Although numerical values differ, the overall drift results did not change, independent of reference nozzle considered.CONCLUSIONS:The objective of this study is to quantify the effect of tank-mix additives in tap water on the drift reduction with a flat-fan agricultural nozzles. The influence of each additive in terms of drift reduction is presented in this example (Table 7), compared to tap water and LI 700® STAR (marketed antidrift reference reference).The drift reduction potential of Solution D is further supported by the wind tunnel drift study, with both concentrations showing a percentage drift reduction of just over 70% compared to reference nozzle. For Solution B, the drift reduction was more concentration dependant with 64.13% for 0.15% v / v compared to reference nozzle. While for 0.25% v / v drift reduction is 70.95% compared to reference nozzle.. Overall, Solution B at 0.25%, Solution D at 0.15% and 0.25%, and LI 700 STAR® at 0.25%, all resulted in similar drift reducing values of around 70% compared to reference nozzle, for the nozzle and pressure settings used during the trial, while solution B at 0.15% provide a slightly below reducing values of around 64.13% % compared to reference nozzle, for the nozzle and pressure settings used during the trial.Solution B, Solution D are both based on tall oil fatty acid and the last one contains an additional terpen. They behave in a way that is close to the market reference in term of drift reduction even at lower concentration. The terpen addition allows to be bring additional improvements: higher drift reduction and lower dose.

Claims

Claims

1. Use of tall oil fatty acids (TOFA) as a phytosanitary adjuvant.

2. Use of tall oil fatty acids (TOFA) to prevent and / or reduce spray drift upon application of a phytosanitary composition to a plant.

3. A method for generating droplets comprising a step of spraying a composition comprising tall oil fatty acids (TOFA).

4. The method according to claim 3, wherein the concentration of TOFA in said composition is comprised between 200 and 900 g / L, preferably 300 and 800g / L, more preferably between 400 and 600 g / L.

5. The method according to claim 3 or 4, wherein said composition further comprises a surfactant.

6. The method according to any one of claims 3 to 5, wherein said composition further comprises a terpene alcohol.

7. The method according to any one of claims 3 to 6, wherein said composition further comprises a phytosanitary product.

8. A phytosanitary adjuvant comprising tall oil fatty acids (TOFA) and a surfactant.

9. The phytosanitary adjuvant according to claim 8, wherein the concentration of TOFA is comprised between 200 and 900 g / L, preferably 300 and 800g / L, more preferably between 400 and 600 g / L.

10. The phytosanitary adjuvant according to claim 8 or 9, wherein said adjuvant further comprises a terpene alcohol.

11. A phytosanitary composition comprising the phytosanitary adjuvant according to any one of claims 8 to 10 and a phytosanitary product.

12. The phytosanitary adjuvant or phytosanitary composition according to any one of claims 8 to 11, wherein said composition is in the form of droplets.

13. A method for treating a plant with a phytosanitary product, wherein said method comprises mixing said phytosanitary product with tall oil fatty acids (TOFA) and applying said mixture to a plant by spraying.

14. A method for preventing spray drift upon application of a phytosanitary composition on a plant, wherein said method comprises adding tall oil fatty acids (TOFA) to said composition prior application.

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