Natural fungicide composition

Abstract

A method for treating Black Sigatoka fungus in crops of the Musaceae family by applying a fungicidal composition comprising garlic oil, rosemary oil, thyme oil and cinnamon oil.

Claims

1. A method for treating Black Sigatoka fungus in crops of the Musaceae family comprising: applying a fungicidal composition to the crops comprising an emulsifier, garlic oil, rosemary oil, thyme oil and cinnamon oil in the following percentages by weight: emulsifier: about 10.0-40.0% garlic oil: about 2.0-5.0% rosemary oil: about 0.5-2.5% thyme oil: about 0.5-2.5% cinnamon oil: about 0.5-2.5% peppermint oil: about 0.5-3%.

2. The method of claim 1 in which the garlic oil, rosemary oil, thyme oil and cinnamon oil of the fungicidal composition are dispersed in a vegetable oil.

3. The method of claim 2 in which the vegetable oil is palm olein.

4. The method of claim 2 in which the fungicidal composition includes an emulsifier selected from the group consisting of polysorbate, propylene glycol alginate, and mixtures thereof.

5. The method of claim 4 in which the emulsifier is about 32 wt. % polysorbate and 0.125 wt. % propylene glycol alginate.

6. The method of claim 1 in which the fungicidal composition includes an antioxidant.

7. The method of claim 1 in which the fungicidal composition includes xanthan gum.

8. The method of claim 1 in which the fungicidal composition includes spearmint oil.

9. The method of claim 1 in which mineral oil is included in the fungicidal composition at an appropriate level to act as a fungistatic agent.

10. The method of claim 1 in which the fungicidal composition includes, in percentages by weight: palm olein: 59.125 garlic oil: 2.000 rosemary oil: 0.500 thyme oil: 0.500 cinnamon oil: 0.500 polysorbate: 32.000 propylene glycol alginate: 0.125 antioxidant blend: 0.250 spearmint oil: 1.250 peppermint oil: 1.250 soy lecithin: 2.500.

11. The method of claim 1 in which the fungicidal composition is applied to banana crops.

12. The method of claim 11 in which the fungicidal composition is applied by aerial spraying.

13. A method for treating Black Sigatoka fungus in crops of the Musaceae family comprising applying to the crops a composition containing, in percentages by weight: palm olein: about 50.0-80.0% emulsifier: about 10.0-40.0% garlic oil: about 2.0-5.0% rosemary oil: about 0.5-2.5% thyme oil: about 0.5-2.5% cinnamon oil: about 0.5-2.5% antioxidant blend: about 0-0.5% peppermint oil: about 0.5-3%.

14. The method of claim 1 in which the fungicidal composition further includes, in percentage by weight: soy lecithin: about 1.5-3%.

15. The method of claim 13 in which the fungicidal composition further includes, in percentage by weight: soy lecithin: about 1.5-3%.

Description

DETAILED DESCRIPTION

(1) The following examples further illustrate embodiments of the invention but should not be construed as in any way limiting its scope.

First Field Trials

(2) Generally, commercial application of the natural fungicide embodiments will be by aerial spraying using aircraft or helicopters. Therefore, in this example, a natural fungicide composition in accordance with embodiments was applied on a field by nebulization, simulating aerial application. The natural fungicide used in this example was initially in the form of a composition containing, in percentages by weight: palm olein: 74.500 emulsifier: 20.000 garlic oil: 2.000 rosemary oil: 0.500 thyme oil: 0.500 cinnamon oil: 0.500 xanthan gum: 0.500 antioxidant blend: 0.250 spearmint oil: 1.250.

(3) Hydraulic sprayers were used to mix the concentrate natural fungicide with water and mineral oil, and thereby form aqueous droplets that are sprayed on the leaf surface. The fungicide was diluted in water and mineral oil to obtain the different concentrations before spraying to deliver from 2 to 4 liters of the natural fungicide composition per hectare of banana plantation.

(4) After different trials, the optimal application level was found to be 4 liters per hectare with approximately 32 applications per year. It is currently believed that the application level per hectare based on actives should be about 2 to 5 liters (1.8 to 9 kg) of the natural fungicide and about 2 to 7 liters of mineral oil per hectare. And, results can be optimized through synergistic action with systemic treatments and modifications to standard soil fertilization routines.

(5) In this example, the application of 2 to 4 liters of the natural fungicide composition per hectare of banana plantation or 3.7 kg of the natural fungicide composition per hectare substantially prevented the formation of germinative tubes of Black Sigatoka (i.e., leaf damage according to the Stover scale). It is expected that the total number of applications necessary will vary depending weather conditions (rain amount, temperature, etc.), during the growing stage of the fruit.

First Field Trial Results

(6) Fungicidal results were obtained by measuring leaf damage according to the Stover leaf damage severity scale, modified by Gauhl, on a scale of 0 to 6 obtained by applying the following compositions in an experimental banana plantation over a period of 15 weeks: Application of natural fungicide composition as described above. Application of recognized synthetic chemical fungicide. Application of mineral oil. No treatment applied.

(7) At a concentration of 4 liters/hectare, the natural fungicide composition produced results against Black Sigatoka fungus commensurate with the results obtained with a recognized synthetic chemical fungicide, Dithane® 60SC, which is available from Dow Agrosciences (generic name of the active ingredient is mancozeb).

(8) The results for mineral oil alone were substantially inferior to those obtained with the natural fungicide. When no treatment was applied, the level of leaf damage was yet worse.

(9) The results thus indicate that the experimental natural composition performs as a protectant fungicide as effectively as conventional chemical fungicides.

Second Field Trials

(10) Additional field trials were conducted to evaluate the in vitro fungicidal activity of 14 composition embodiments in the treatment of Mycosphaerella fijiensis.

(11) Culture media comprising 2% water-agar (Difco® Bacto® Agar) and 0.001, 0.01, 0.1, 1, 10, 100, and 1,000 mg/L of the active substance were each prepared in a petri dish for each composition. A separate culture media without any active substance was used as a control. For comparative fungicides F-11-01 to F-11-12 listed in Table 1 below, the active substance was the same as the composition as a whole.

(12) TABLE-US-00001 TABLE 1 Comparative Active Substance/ Fungicide Composition F-11-01 Palm Oil F-11-02 Garlic Oil F-11-03 Rosemary Oil F-11-04 Thyme Oil F-11-05 Cinnamon Oil F-11-06 Spearmint Extract F-11-07 Peppermint Oil F-11-08 Antioxidant (BHA-BHT) F-11-09 Polysorbate 80 F-11-10 Soy Lecithin F-11-11 Propylene Glycol Alginate F-11-12 Mint Oil

(13) For sample fungicides F-11-13 and F-11-14, the active substance had the composition shown in Table 2 below. Sample fungicide F-11-13 was prepared at the time that the second field trials were conducted, but sample fungicide F-11-14 had been prepared about a year before the second field trials were conducted and held in storage until the second field trials were undertaken.

(14) TABLE-US-00002 TABLE 2 Inventive Formula wt. % Palm Oil 59.125 Garlic Oleoresin 2.000 Rosemary Oil 0.500 Thyme Oil 0.500 Cinnamon Oil 0.500 Spearmint Extract 1.250 Antioxidant (BHA-BHT) 0.250 Polysorbate 80 32.000 Soy Lecithin 2.500 Propylene Glycol Alginate 0.125 Mint Oil 1.250 100.000

(15) Ascospores of Mycosphaerella fijiensis obtained from a banana plantation that had not been treated with any fungicides were discharged into each petri dish. After discharging the ascospores of Mycosphaerella fijiensis, each sample was incubated for 48 hours at 26° C. in complete darkness. After 48 hours of incubation, the length of 100 germinated ascospores at each concentration was measured.

(16) After collecting the data, the average length of the germinated ascospores was calculated for each concentration. The average inhibition percentage was calculated for each sample fungicide at each concentration using the following formula:

(17) $\%\mathrm{inhibition}=\left(\frac{{\stackrel{\_}{L}}_{\mathrm{control}}-{\stackrel{\_}{L}}_{\mathrm{sample}}}{{\stackrel{\_}{L}}_{\mathrm{control}}}\right)\times 100\%$

(18) where: L.sub.control=average length of germinated ascospores of control sample L.sub.sample=average length of germinated ascospores of sample fungicide.

(19) The average inhibition percentage was used to calculate EC.sub.50 for each sample fungicide. EC.sub.50 is the half maximal effective concentration, which refers to the concentration of sample fungicide that induces a response halfway between the baseline and maximum after a specified exposure time.

Second Field Trial Results

(20) The results for each sample fungicide are summarized in Table 3 below. A lower EC.sub.50 value is desirable because it indicates that the sample fungicide was able to achieve 50% inhibition using a lower concentration of the active ingredient as compared to sample fungicides with higher EC.sub.50 values.

(21) TABLE-US-00003 TABLE 3 Concentration Fungicides (mg/L) % Inhibition Natural Log EC.sub.50 R.sup.2 Value Comparative Fungicide F-11-01 0.001 −5.06 7.27 >1000 0.78 (Palm Oil) 0.01 10.6 0.1 26.51 1 37.59 10 38.67 100 43.49 1000 36.99 Comparative Fungicide F-11-02 0.001 −9.64 1.2 3.33 0.75 (Garlic Oil) 0.01 −10.48 0.1 −1.45 1 −12.77 10 99.28 100 100 1000 100 Comparative Fungicide F-11-02 0.001 21.69 1.92 6.81 0.55 (Rosemary Oil) 0.01 33.37 0.1 31.57 1 38.55 10 29.04 100 43.25 1000 100 Comparative Fungicide F-11-04 0.001 9.64 4.84 127.6 0.51 (Thyme Oil) 0.01 −8.8 0.1 2.05 1 −9.4 10 −8.92 100 58.07 1000 100 Comparative Fungicide F-11-05 0.001 18.43 1.15 3.18 0.75 (Cinnamon Oil) 0.01 5.06 0.1 7.35 1 23.73 10 37.11 100 100 1000 100 Comparative Fungicide F-11-06 0.001 −10.94 3.71 41.06 0.74 (Spearmint Oil) 0.01 9.33 0.1 18.35 1 16.42 10 17.27 100 40.56 1000 100 Comparative Fungicide F-11-07 0.001 −8.48 3.73 41.59 0.8 (Peppermint Oil) 0.01 −16.85 0.1 −2.47 1 −4.83 10 21.14 100 58.91 1000 100 Comparative Fungicide F-11-08 0.001 1.61 3.15 23.32 0.77 (Antioxidant (BHA-BHT)) 0.01 32.4 0.1 5.58 1 18.24 10 48.93 100 56.33 1000 77.68 Comparative Fungicide F-11-09 0.001 37.98 10.45 >1000 0.11 (Polysorbate 80) 0.01 42.6 0.1 11.91 1 31.87 10 52.04 100 46.24 1000 Comparative Fungicide F-11-10 0.001 ND ND ND ND (Soy Lecithin) 0.01 (ND: The soy lecithin was 0.1 unable to be dissolved in any of 1 the three solvents evaluated: 10 water, acetone, and methanol.) 100 1000 Comparative Fungicide F-11-11 0.001 39.06 5.57 1.13 0.12 (Propylene Glycol Alginate) 0.01 34.44 0.1 35.84 1 30.58 10 −1.5 100 32.3 1000 97.85 Comparative Fungicide F-11-12 0.001 −4.819 138.54 >1000 0.1 (Soybean Oil) 0.01 −6.627 0.1 4.217 1 7.952 10 2.892 100 4.096 1000 −3.855 Sample Fungicide F-11-13 0.001 5.36 1.85 6.37 0.85 (produced for trials) 0.01 8.69 0.1 19.42 1 27.25 10 29.72 100 75.21 1000 99.03 Sample Fungicide F-11-14 0.001 37.88 −0.46 0.62 0.52 (produced more than 1 year 0.01 47.42 before trials) 0.1 42.6 1 46.57 10 47.42 100 47.64 1000 88.41

(22) The fungicides with higher activity were: F-11-14 (the aged formula, EC.sub.50=0.62 mg/L), F-11-11 (Propylene Glycol Alginate, EC.sub.50=1.13 mg/L), F-11-05 (Cinnamon Oil, EC.sub.50=3.18 mg/L), and F-11-02 (Garlic Oil, EC.sub.50=3.3 mg/L). Fungicides F-11-01 (Palm Oil), F-11-09 (Polysorbate 80), and F-11-12 (Soy Lecithin) each had EC.sub.50>1,000 mg/L, which means that none of these samples was able to achieve 50% inhibition at the highest concentration (1,000 mg/L) evaluated.

(23) The lowest inhibiting concentration, that is, the minimum concentration that achieves total (100%) inhibition of the germinated ascospores was 100 mg/L for F-11-02 (Garlic Oil) and F-11-05 (Cinnamon Oil) and 1,000 mg/L for F-11-03 (Rosemary Oil), F-11-04 (Thyme Oil), F-11-06 (Spearmint Extract), and F-11-07 (Mint Oil). The lowest inhibiting concentration could not be determined for the remaining sample fungicides because none of those achieved total inhibition at the concentrations that were evaluated.

(24) The EC.sub.50 for sample fungicide F-11-13 was 6.4 ppm. Table 4 below shows the amount of each component of sample fungicide F-11-13 at a total concentration of 6.4 ppm.

(25) TABLE-US-00004 TABLE 4 F-11-13 wt. % ppm Palm Oil 59.125 3.784 Garlic Oleoresin 2.000 0.128 Rosemary Oil 0.500 0.032 Thyme Oil 0.500 0.032 Cinnamon Oil 0.500 0.032 Spearmint Extract 1.250 0.080 Antioxidant (BHA-BHT) 0.250 0.016 Polysorbate 80 32.000 2.048 Soy Lecithin 2.500 0.160 Propylene Glycol Alginate 0.125 0.008 Mint Oil 1.250 0.080 100.000 6.400

(26) The unexpected synergistic effect of combining garlic oil, rosemary oil, thyme oil, and cinnamon oil to produce a natural fungicide to eradicate Black Sigatoka is evident from the Second Field Results. The results show that significantly lower amounts of garlic oil, rosemary oil, thyme oil, and cinnamon oil were used in combination in sample fungicides F-11-13 and F-11-14 to achieve 50% inhibition as compared to the higher amounts required for each of garlic oil, rosemary oil, thyme oil, and cinnamon oil when used alone as a fungicide.

(27) In addition, the results show that storing the fungicidal composition (e.g., F-11-14) for more than one year does not adversely affect its fungicidal activity. Surprisingly, the fungicidal activity of F-11-14 increased and its EC.sub.50 was 0.62 ppm. Without being bound by theory, the greater fungicidal activity of the F-11-14 is believed to result from secondary metabolites that are created during storage.

(28) The embodiments disclosed here provide further fungicidal compositions that are expected to produce as good or better results than the embodiments disclosed in U.S. patent application Ser. No. 14/213,298. The differences between the embodiments disclosed here and the embodiments of U.S. patent application Ser. No. 14/213,298 include: increased the amount of emulsifier by about 50% or more added soy lecithin improving adhesion of the natural fungicide to the surface of the plant added peppermint oil, which together with spearmint oil, is believed to provide significant protection against other fungi, such as Phytophthora decreased the palm olein

(29) All references are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

(30) The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the ranges, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. The illustrated embodiments are exemplary only, and should not be taken as limiting the scope of the invention.