Methods for fungicidal treatment of harvested crops

Abstract

A method for cold fogging of a fungicidally active compound onto post-harvest crops.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to the treatment of harvested crops, and more particularly to compositions and methods for treating crops after harvest. [Background technology]

[0002] As described in Stathers, T et al., "A scoping review of interventions for crop post-harvest loss reduction in sub-Saharan Africa and South Asia," Nat Sustain 2020, 3, 821-835, by 2050, the world's population is expected to reach 9.7 billion. Such an increase would require a 60% increase in food production compared to 2005-2007 levels. Therefore, reducing post-harvest losses of food crops is recognized as a key component of sustainably increasing agricultural productivity.

[0003] Indeed, post-harvest crop losses not only result in the loss of valuable crops, but also in the loss of inputs (e.g., water, energy, labor, etc.) necessary to produce and distribute the crops. Given their considerable scale, reducing post-harvest losses can help (1) create more sustainable and resilient food systems and (2) reduce greenhouse gas emissions. Indeed, reducing post-harvest losses can further optimize agricultural productivity and increase the revenues of small-scale food producers and related value chain actors. Therefore, there remains a need for methods of protection against post-harvest crop losses. Summary of the Invention [Means for solving the problem]

[0004] An embodiment includes a method of cold fogging a pile or stack of harvested crops with a composition having about 1% to about 20% (weight percent) of a first fungicidally active compound, about 1% to about 90% (weight percent) water, and at least one filler. [Brief explanation of the drawings]

[0005] [Figure 1A-1B] 1 shows the volume median diameter (VMD) of the cold fogging formulation. [Figure 2A-2B] 1 shows pesticide residues from cold fogging and conventional spraying. [Figure 3] 1 is an exemplary image of a typical storage unit for potatoes after harvest. DETAILED DESCRIPTION OF THE INVENTION

[0006] Before describing particular embodiments in more detail, it is to be understood that this disclosure is not limited to described embodiments, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, as the scope of the present disclosure will be limited only by the appended claims.

[0007] Set forth herein are several definitions. Such definitions are intended to encompass grammatical equivalents.

[0008] As used herein, the term "about" when referring to a measurable value such as an amount, time duration, etc. is meant to encompass variation, however such variation depends on the particular component being referred to and the context as would be understood by one of ordinary skill in the art.

[0009] Where a range of values is provided, unless the context clearly dictates otherwise, it is understood that each intervening value, to the tenth of the unit of the lower limit, between the upper and lower limit of that range, and any other stated or intervening value in that stated range, is encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure.

[0010] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Methods and materials similar or equivalent to those described herein can also be used in the practice or testing of this disclosure; representative exemplary methods and materials are described herein.

[0011] Each of the individual embodiments described and illustrated herein has distinct components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the disclosure. Any recited method can be carried out in the order of events recited or in any other order which is logically possible.

[0012] The term pesticide active ingredient includes compounds or ingredients registered as biologically active against agricultural pests. Generally, pesticide active ingredients include compounds listed in The Pesticide Manual, 12th edition, 2001, British Crop Protection Council. Pesticides include, but are not limited to, selective herbicides, fungicides, other insecticides, bactericides, insect growth regulators, plant growth regulators, nematicides, molluscicides, or mixtures of some of these preparations.

[0013] In general, the present disclosure provides compositions for post-harvest treatment, as well as methods for using and preparing the compositions. In some embodiments, the compositions include a fungicidal active compound, water, and a filler. These compositions can be used in cold fogging applications.

[0014] Current post-harvest protection methods include techniques such as spraying or misting a composition containing an active pesticide ingredient onto harvested crops before or during storage of the crop, or thermal fogging, which are distinct from cold fogging.

[0015] For example, spraying or misting differs from cold fogging based at least on droplet size, coverage, and accuracy. Generally, spraying or misting physically differs from cold fogging in the droplet size used to apply the active pesticide ingredient. Fog particles can have a diameter of less than about 50 microns, while mist droplets tend to have a diameter greater than 50 microns. The difference in droplet size affects the ability of the droplets to travel and cover an area.

[0016] Thermal fogging differs from cold fogging at least in the temperature of the composition. Thermal foggers use heat to vaporize and atomize the composition, while cold foggers use pressure and other techniques to produce small droplet sizes. Due to the heat involved in thermal fogging, the use of heat-sensitive pesticide active ingredients can be disadvantageous. Furthermore, cold fogging allows the use of existing aqueous formulations without concern for solvent / phytotoxicity effects, and cold fogging does not have the same explosion risks that can result from thermal fogging operations.

[0017] The term "fungicidally active compound" as used herein includes compounds active against plant pathogenic fungi. Fungicidally active compounds include compounds that are solid at room temperature (25°C) and compounds that are liquid at room temperature. The compounds may include several types of compounds, such as triazole derivatives, strobilurins, carbamates (including thiocarbamates and dithiocarbamates), benzimidazoles (thiabendazole), N-trihalomethylthio compounds (captans), substituted benzenes, carboxamides, phenylamides, phenylpyrroles, and succinate dehydrogenase inhibitors.

[0018] Suitable triazole derivatives may include propiconazole, difenconazole, tebuconazole, tetraconazole, and triticonazole. Suitable strobilurins include trifloxystrobin, azoxystrobin, kresoxim-methyl, pyraclostrobin, and picoxystrobin. In another example, a suitable carbamate includes thiram. Suitable substituted benzenes include pentachloronitrobenzene (PCNB) and chlorothalonil. Suitable carboxamides include carboxin. Suitable phenylamides include metalaxyl; metalaxyl consisting of more than 70% by weight of the R-enantiomer; metalaxyl consisting of more than 85% by weight of the R-enantiomer; metalaxyl consisting of more than 92% by weight of the R-enantiomer; metalaxyl consisting of more than 97% by weight of the R-enantiomer; and mefenoxam (i.e., R-metalaxyl or metalaxyl-M). Suitable succinate dehydrogenase inhibitors include benzovindiflupyr.

[0019] Other suitable fungicidally active compounds include benomyl (also known as benlate), bitertanol, carbendazim, capropamide, cymoxanil, cyprodinil, ethirimol, fenpiclonil, fenpropimorph, fluquinconazole, flutolanil, flutriafol, fosetyl-aluminum, fuberidazole, guazatine, hymexanol, kasugamycin, imazalil, imibenconazole, iminooctadine triacetate, Mention may be made of ipconazole, iprodione, mancozeb, maneb, mepronil, metconazole, metiram, myclobutanil, nuarimol, oxadixyl, oxine-copper, oxolinic acid, pefurazoate, pencycuron, prochloraz, propamocarb hydrochloride, pyroquilon, silthiofam, tecnazene, thifluzamide, thiophenate-methyl, tolclofos-methyl, triadimenol, triazoxide and triflumizole.

[0020] In some embodiments, the fungicidally active compound may comprise a combination of compounds. In one example, the mixture of fungicidally active compounds comprises fludioxonil and thiabendazole. In another example, the mixture of fungicidally active compounds comprises fludioxonil and azoxystrobin. In another example, the mixture of fungicidally active compounds comprises fludioxonil and propiconazole. In another example, the mixture of fungicidally active compounds may comprise fludioxonil, mefenoxam, and difenoconazole. In another example, the mixture of fungicidally active compounds comprises fludioxonil, mefenoxam, difenoconazole, and azoxystrobin.

[0021] Preferred pesticide active ingredients include pydiflumetofen, azoxystrobin, fludioxonil, difenoconazole, thiabendazole, and cyclobutrifluram. Certain embodiments specifically include synthetic pesticides. However, other pesticide active ingredients worth mentioning include ozone, peroxyacetic acid, hydrogen peroxide, chlorine dioxide, Pseudomonas syringae strain ESC-10, and peroxyacetic acid.

[0022] The amount of fungicidally active compound can vary. In typical embodiments, the fungicidally active ingredient represents about 1% to about 50% by weight of the composition. In further examples, the fungicidally active ingredient can represent at least one of: about 1% to about 25% by weight of the composition; about 1% to about 20% by weight of the composition; about 1% to about 15% by weight of the composition; about 1% to about 10% by weight of the composition; and about 1% to about 5% by weight of the composition. In some embodiments, the first fungicidally active compound can be about 1% to about 20% (weight percent). For example, the first fungicidally active compound can be about 5% to about 15% by weight, or even about 6% to 12% by weight. The composition may further comprise a second fungicidally active compound that is different from the first fungicidally active compound and may be present at about 1% to about 20% (weight percent), for example, about 5% to about 15% by weight, or even about 6% to about 12% by weight. Some embodiments may also comprise a third fungicidally active compound, where all three fungicidally active compounds are different, and may be present at about 1% to about 20% (weight percent), about 5% to about 15% by weight, or even about 6% to about 12% by weight.

[0023] The amount of water in the composition can vary. In typical embodiments, water represents about 1% to about 90% by weight of the composition. In further examples, water can represent at least one of about 20% to about 80% by weight of the composition; about 30% to about 80% by weight of the composition; about 40% to about 80% by weight of the composition; about 50% to about 80% by weight of the composition; and about 60% to about 75% by weight of the composition. In many examples, water represents about 70% by weight of the composition.

[0024] In some embodiments, the composition may contain a filler. As used herein, a filler refers to an ingredient that stabilizes and homogenizes the active pesticide ingredient throughout the fogging composition.

[0025] Fillers suitable for use may include at least one of 2-ethyl-1-hexanol, α-tocopherol, amyl acetate, decyl alcohol, dimethylformamide, dimethyl sulfoxide, dipropylene glycol, ethylene glycol, glycerin, hexanol, isopropyl myristate, methyl isobutyl ketone, methyl oleate, N-methylpyrrolidinone, octanol, oleic acid, oleyl alcohol, propylene glycol, p-xylene, triacetin. Other fillers may be preferred.

[0026] The amount of filler can vary, for example, from about 0.1% to about 50% by weight of the treatment composition; from about 5% to about 45% by weight of the treatment composition; from about 5% to about 40% by weight of the treatment composition; from about 5% to about 35% by weight of the treatment composition; from about 5% to about 30% by weight of the treatment composition; from about 5% to about 25% by weight of the treatment composition, from about 5% to about 20% by weight of the treatment composition; from about 5% to about 15% by weight of the treatment composition; and from about 8% to about 12% by weight of the treatment composition.

[0027] Certain composition embodiments disclosed herein are particularly suitable for cold fogging applications, and even more particularly, in many embodiments, are suitable as ready-to-fog (RTF) compositions for cold fogging applications. As used herein, RTF compositions include compositions that do not require at least one of dilution prior to cold fogging or combination of an active ingredient with a carrier (e.g., by melting, heating, or other methods) prior to fogging. Thus, in many examples, the RTF compositions disclosed herein may be contained within a storage and transport container and be ready to fogging when the storage and transport container is opened.

[0028] In embodiments where the composition is not RTF, the composition can be diluted prior to cold fogging. The dilution ratio can be 1:0.5, 1:1, 1:2, 1:4, 1:8, 1:10, 1:14, 1:16, 1:25, 1:50, 1:64, greater than 1:100, etc. The dilution ratio can be selected based on the concentration of pesticide in the composition and the desired residue in the crop after harvest.

[0029] A variety of cold foggers can be used. Examples include the Typhoon I, Maxi-Pro 2D, Versa Fogger, Nightstar, and Dyna Jet L30. Alternatively, the nozzles of the cold fogger can be mounted on the ceiling or wall of the structure used to store the harvested crop. These systems can be built to the specifications of the particular storage facility and the crop being stored.

[0030] The compositions can be used to generate fogs with a variety of particle sizes for uniform distribution of active ingredients during application. Embodiments include compositions capable of generating fogs with a particle size volume median diameter (VMD) ranging from about 2 to about 20 microns. In many instances, the compositions can generate fogs with a particle size VMD ranging from about 4 to about 20 microns or from about 3 to about 10 microns. The particle sizes achievable by the present disclosure, particularly those between about 5 and about 10 microns, allow for excellent distribution of active ingredients to crops after harvest. VMD particle size can be measured using a Sympatec HELOS laser diffraction sensor approximately one meter from the fogger outlet.

[0031] In some embodiments, the area where harvested crops are stored is a large structure. For example, the area can store at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1,000, or more tons (kg) of crops. An exemplary image of an area for post-harvest processing is shown in FIG. 3.

[0032] In some instances, fillers can be used to enhance the visibility of the composition during fogging. These fillers may be the same or different from the fillers used to stabilize and homogenize the composition. Increasing the visibility of the fogging composition can provide several benefits, including, for example, at least one of reducing the exposure of application equipment to the fogging composition or increasing contact of the fogging composition with the harvested crop. For example, the composition can be fogging to provide visibility, as measured by light obscuration, in at least one of the following ranges: 20-70% Copt; 25-65% Copt; 30-60% Copt; 35-55% Copt; and 40-50% Copt. Copt measurements can be performed using a Sympatec HELOS laser diffraction sensor approximately one meter from the exit of the fogger.

[0033] The compositions disclosed herein may also include other inert additives, including thickeners, flow enhancers, wetting agents, antifoaming agents, biocides, buffers, lubricants, drift control agents, deposition enhancers, adjuvants, evaporation retardants, cryoprotectants, stabilizing metal salts or hydroxides, UV protectants, fragrances, and the like.

[0034] Embodiments also include methods of treating fruits or vegetables after harvest, for example, by applying the compositions disclosed herein. As noted above, preferred methods of application include, for example, application by cold fogging as described above.

[0035] In many embodiments, the target crop to be protected can include any type of fruit or vegetable. Exemplary post-harvest materials include apples, pears, plums, grapes, peaches, almonds, cherries, strawberries, raspberries, blackberries, bananas, spinach, lettuce, asparagus, cabbage, carrots, onions, tomatoes, potatoes, sugar beets, peppers, kidney beans, lentils, peas, soybeans, mallows, cucumbers, melons, oranges, lemons, limes, grapefruit, mandarins, etc. It should be clear that this list does not represent any limitation on the target crops.

[0036] The following examples are illustrative of the present invention but are not intended to limit its scope. In the examples below, and throughout this specification, % generally refers to w / w unless otherwise indicated. [Example]

[0037] Example 1 The pesticide formulations were tested by both spray and cold fogging application to compare spray quality and determine the amount of active compound on the leaves. Four different treatments were sprayed at two different dilutions.

[0038] [Table 1]

[0039] Palladium® is a commercial fungicidal composition sold by Syngenta®, having 37.5% w / w cyprodinil and 25% w / w fludioxonil.

[0040] Mural® Fungicide is a commercial fungicidal composition sold by Syngenta® having 30% w / w azoxystrobin and 15% w / w benzovindiflupyr.

[0041] Segovis® Fungicide is a commercial fungicidal composition sold by Syngenta® that has 18.7% oxathiapiprolin.

[0042] Mainspring® GNL Insecticide is a commercial insecticidal composition sold by Syngenta® that has 18.66% w / w cyantraniliprole.

[0043] For conventional treatments: For each treatment, three organically grown begonias were placed in a row in the spray chamber 20 inches below the spray nozzle. The plants were sprayed with each treatment at 40 psi and 3 mph through an 8001 nozzle. One hour after application, leaves were harvested from each of the three plants, placed in separate Ziploc bags labeled with ID, and sent for residue analysis.

[0044] For fog treatments, fog applications were performed inside a tent to contain the fog for several hours after application. Each treatment was sprayed onto the plants through a Dramm nozzle at 20 psi from a fixed position 6 feet above the plants. To avoid contamination, the tent walls were covered with plastic sheeting, which was replaced after each treatment. One treatment was sprayed per day, and leaves were collected several hours after application. A ventilation system was not used to prolong droplet circulation. The tent was sealed during application to avoid losses. Calculations were performed based on the Dramm manual operating instructions. Two different collector types were acquired: (1) begonia leaves (three replicates, leaves) collected, frozen, and processed for analysis; active ingredient quantified in ppb; and (2) filter paper (three replicates), active ingredient quantified in ppb.

[0045] The average (VMD) and average (10) results are shown in Figures 1A and 1B. As shown, the average (VMD) remained below 15 microns. The retention results are shown in Figures 2A and 2B, and the retention results shown for fogging residue were as good as, if not better than, spray application, while using less water.

[0046] Example 2 Stadium® fungicide (12.51% w / w azoxystrobin, 12.51% w / w fludioxonil, and 9.76% w / w difenoconazole, commercially available from Syngenta) was cold fogged by first diluting 1 part Stadium® in 14 parts water, then further diluting the mixture by pouring it into a carrier stream of water. Residue was measured on a pile of potatoes (approximately 5 potatoes high) and on filter paper. The particle size measured from the cold fogger was approximately 30 microns and was unable to penetrate the potato pile. The residue measured from the potatoes at the bottom of the pile was less than 10% of the residue measured at the top of the pile. Additionally, this treatment resulted in wet potatoes. After 24 hours, the potatoes at the top of the pile were still visibly wet, while the majority of the bottom was dry.

[0047] Example 3 The cold fogging machine parameters can be modified to achieve smaller particles, for example, 15 micron fog particles, as shown in Example 1. Achieving smaller droplet sizes can allow the droplets to more efficiently pass through piles or stacks of harvested crops such as potatoes.

[0048] While only a few exemplary embodiments of the present invention have been described in detail above, those skilled in the art will readily appreciate that many modifications to the exemplary embodiments are possible without materially departing from the novel teachings and advantages of the present invention. Accordingly, all such modifications are intended to be included within the scope of the present invention as defined in the following claims.

Claims

1. With 1% to 20%, by weight percent, of the first fungicidal compound; 1% to 90%, by weight, water and; at least one filler and A method comprising cold fogging a composition containing onto a pile or stack of harvested crops.

2. The method according to claim 1, wherein the first fungicidal compound comprises at least one compound selected from triazole derivatives, strobilurin, carbamates, benzimidazole, N-trihalomethylthio compounds, substituted benzenes, carboxamides, phenylamides, phenylpyrroles, and succinate dehydrogenase inhibitors.

3. The method according to claim 1, wherein the first fungicidal compound is selected from fludioxonil, mefenoxam, metalaxyl, difenoconazole, propiconazole, thiabendazole, and azoxystrobin.

4. The method according to claim 1, wherein the harvested crop is a potato.

5. The method according to claim 1, wherein the cold fogging includes biasing the composition under high pressure and passing it through an orifice.

6. The method according to claim 5, wherein the biasing force is provided by direct compression of the composition by a pump.

7. The method according to claim 5, wherein the high pressure is 2500 to 3000 psi.

8. The method according to claim 5, wherein the biasing force is provided by compressed air.

9. The method according to claim 1, wherein the cold fogging comprises generating ultrasound to atomize the composition.

10. The method according to claim 1, wherein the cold fogging includes generating kinetic energy to atomize the liquid.

11. The method according to claim 1, wherein the cold fogging comprises cold fogging directly into a storage room for the harvested crops.

12. The method according to claim 1, wherein the cold fogging includes introducing the fog into a plenum chamber of a large volume of slow-moving air mass.

13. The method according to claim 1, wherein the temperature of the composition is 33°F to 95°F (0°C to 35°C) in the cold fogger.

14. The method according to claim 1, wherein the fog particles have a volume median diameter of 4 to 20 microns.

15. The method according to claim 1, wherein the fog particles have a volume median diameter of 5 to 10 microns.

16. The method according to claim 1, further comprising mixing a concentrated composition containing the first fungicidal compound to form the composition.

17. (a) the ratio of the first fungicidal compound, the water, and the at least one filler, (b) Temperature of the composition during fogging, (c) Flow rate of the composition in the cold fogger apparatus, (d) Energy source for atomization, and (e) Orifice size of the nozzle on the cold fogger device The method according to claim 1, further comprising configuring the cold fogger device to produce a fog having a uniform dose composition having a volume median diameter of 4 to 20 microns by adjusting at least one of the following:

18. The method according to claim 1, wherein cold fogging is performed by diluting the composition.

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