PHYTOSANITARY COMPOSITION COMPRISING ESSENTIAL OILS THAT POTENTIATE ANTIFUNGAL ACTIVITY

Abstract

The present invention relates to phytosanitary compositions with fungicidal properties that comprise a mixture of essential oils obtained from plants and agents with known fungicidal properties, such as alkali metal or ammonium bicarbonates, and compounds based on copper or the salts thereof, for use, principally, in contact-protection against fungal infections in cultivated plants and post-harvest, and also in other antifungal applications. In said compositions, the effect of the agents that have known fungicidal properties is potentiated synergistically by the aforementioned essential oils. The present invention also relates to the use of said essential oils as potentiators for agents with known fungicidal properties.

Claims

1. A phytosanitary composition comprising: (A) one or more active compounds of one or more essential oils, wherein the one or more active compounds is chosen from carvacrol, thymol, or combination thereof; and (B) potassium bicarbonate, wherein the phytosanitary composition has antifungal activity.

2. The phytosanitary composition of claim 1, wherein the one or more essential oils is chosen from thyme oil, oregano oil, or combination thereof.

3. The phytosanitary composition of claim 1, wherein the phytosanitary composition is a liquid.

4. The phytosanitary composition of claim 1, wherein the phytosanitary composition consists essentially of the one or more active compounds and the potassium bicarbonate.

5. The phytosanitary composition of claim 1, wherein the phytosanitary composition consists of the one or more active compounds and the potassium bicarbonate.

6. The phytosanitary composition of claim 1, wherein the phytosanitary composition comprises: from 0.01% to 99.99% of the one or more essential oils, wherein the 0.01% to 99.99% of the one or more essential oils is a weight percentage of the phytosanitary composition, and from 99.99% to 0.01% of the potassium bicarbonate, wherein the 99.99% to 0.01% of the potassium bicarbonate is a weight percentage of the phytosanitary composition.

7. The phytosanitary composition of claim 1, wherein the one or more active compounds is the carvacrol.

8. The phytosanitary composition of claim 1, wherein the phytosanitary composition comprises: a concentration of at least 0.1 ppm of the carvacrol, and a concentration of 30 mM of the potassium bicarbonate.

9. The phytosanitary composition of claim 1, wherein the phytosanitary composition comprises: a concentration of at least 0.31 ppm of the carvacrol, and a concentration of 30 mM of the potassium bicarbonate.

10. The phytosanitary composition of claim 1, wherein the phytosanitary composition comprises: a concentration of at least 10 ppm of the carvacrol, and a concentration of 30 mM of the potassium bicarbonate.

11. The phytosanitary composition of claim 1, wherein the phytosanitary composition comprises: a concentration of 0.1 ppm, 0.31 ppm, or 10 ppm of the carvacrol, and a concentration of 30 mM of the potassium bicarbonate.

12. The phytosanitary composition of claim 1, wherein the one or more active compounds is the thymol.

13. The phytosanitary composition of claim 1, wherein the phytosanitary composition comprises: a concentration of at least 0.31 ppm of the thymol, and a concentration of 30 mM of the potassium bicarbonate.

14. The phytosanitary composition of claim 1, wherein the phytosanitary composition comprises: a concentration of at least 1 ppm of the thymol, and a concentration of 30 mM of the potassium bicarbonate.

15. The phytosanitary composition of claim 1, wherein the phytosanitary composition comprises: a concentration of at least 10 ppm of the thymol, and a concentration of 30 mM of the potassium bicarbonate.

16. The phytosanitary composition of claim 1, wherein the phytosanitary composition comprises: a concentration of 0.31 ppm, 1 ppm, or 10 ppm of the thymol, and a concentration of 30 mM of the potassium bicarbonate.

17. A method of disinfecting harvested agricultural products, the method comprising contacting the harvested agricultural products with the phytosanitary composition of claim 1.

18. The method of claim 17, wherein the one or more active compounds consists of the carvacrol, the thymol, or the combination thereof.

19. A phytosanitary composition comprising: (A) one or more active compounds of thyme oil, oregano oil, or combination thereof, wherein the one or more active compounds is chosen from carvacrol, thymol, or combination thereof; (B) potassium bicarbonate; and (C) one or more fertilisers, herbicides, insecticides, plant growth regulators, or combination thereof.

Description

EXAMPLES

Example 1 (Comparative)

[0025] Inhibition of growth of the fungus Botrytis cinerea by KHCO.sub.3 alone.

[0026] The fungus Botrytis cinerea was cultured in PDB (potato dextrose broth) medium with different concentrations of KHCO.sub.3 and the % inhibition representing the extent to which growth was impeded in comparison with a control which did not have the compound under test, in this case KHCO.sub.3, was determined. The % inhibition was calculated in the following way:

% inhibition=[(OD.sub.control?OD.sub.x)/OD.sub.control]?100

[0027] where OD.sub.control is the optical density of the control culture (without test compound) and OD.sub.x is the optical density of the culture with the test substance. The optical density of the liquid culture was measured 24 hours after the start of culturing.

[0028] The following results were obtained (Table I):

TABLE-US-00001 TABLE I Inhibition of the growth of B. cinerea by KHCO.sub.3 KHCO.sub.3 concentration (mM) 0 10 15 20 25 30 Inhibition 0 34.2 ? 6.7 37.0 ? 38.8 ? 6.8 39.7 ? 0.7 46.9 ? 2.7 (%) ? SD 11.3

[0029] As will be seen from the table above, with a KHCO.sub.3 concentration between 10 and 25 mM similar results were obtained as regards inhibition of the B. Cinerea culture. However greater inhibition was obtained at 30 mM.

Example 2. (Comparative)

[0030] Inhibition of growth of the fungus Botrytis cinerea by carvacrol alone.

[0031] The fungus B. cinerea was cultured in a similar way to Example 1 with the difference that different concentrations of carvacrol, the compound isolated from the essential oil of oregano, were used in the medium. The 24 hour optical density of the culture was measured and the results are shown in Table II.

TABLE-US-00002 TABLE II Inhibition of the growth of B. cinerea by Carvacrol Carvacrol concentration (ppm) 0.1 0.31 1 3.1 10 31 100 Inhibition 0 10.5 ? 7.7 13.7 ? 4.1 22.4 ? 3.4 21.3 ? 5.0 51.4 ? 5.5 74.4 ? 1.1 (%) ? SD

Example 3

[0032] Inhibition of growth of the fungus Botrytis cinerea by the composition according to this invention (Carvacrol+KHCO.sub.3).

[0033] The fungus B. cinerea was cultured in a similar 5 way to Example 1 with the difference that different concentrations of carvacrol were used in the medium and that a constant concentration of KHCO.sub.3 (30 mM) was used for all the cultures. The optical density of the culture was measured at 24 hour and the results are 10 shown in Table III.

TABLE-US-00003 TABLE III Inhibition of the growth of B. cinerea by the composition according to this invention (Carvacrol + KHCO.sub.3) KHCO.sub.3 30 30 30 30 30 30 30 concentration (mM) Carvacrol 0.1 0.31 1 3.1 10 31 100 concentration (PPm) Inhibition 86.1 ? 2.2 84.2 ? 3.6 48.9 ? 3.0 52.7 ? 2.6 82.5 ? 3.7 86.5 ? 1.3 91.1 ? 1.1 (%) ? SD

[0034] As will be seen, a carvacrol concentration as low as 0.1 ppm, whose inhibiting effect alone is zero (see Example 2) effectively doubles the inhibiting capacity of the KHCO.sub.3, achieving levels of inhibition which are not even obtained with KHCO.sub.3 concentrations that are toxic to plants.

Example 4

[0035] Inhibiting effect of copper oxychloride alone on the fungus Alternaria alternata.

[0036] Alternaria alternata was cultured in a similar way to Example 1 with the difference that different concentrations of copper oxychloride, a copper-based fungicide extensively used in agriculture, were used in the medium. The 24 hour optical density of the culture was measured and the results are shown in Table IV.

TABLE-US-00004 TABLE IV Inhibition of A. alternate by copper oxychloride Copper oxychloride concentration (ppm) 0.1 0.5 1 5 10 15 20 Inhibition 3.1 ? 6.4 0.0 ? 6.7 9.9 ? 0.9 10.0 ? 8.4 23.1 ? 4.7 37.4 ? 3.6 61.3 ? 6.7 (%) ? SD

Example 5

[0037] Inhibition of the fungus Alternaria alternata by Carvacrol alone.

[0038] Alternaria alternata was cultured in a similar way to Example 2. The 24 hour optical density of the culture was measured and the results are shown in Table 15 V.

TABLE-US-00005 TABLE V Inhibition of A. alternate by Carvacrol Carvacrol concentration (ppm) 10 31 100 310 1000 Inhibition 17.7 ? 11 27.2 ? 14 74.6 ? 8 97.2 ? 7 93.0 ? 6.0 (% ? SD)

Example 6

[0039] Inhibition of the fungus Alternaria alternata by the composition according to this invention (Carvacrol+copper oxychloride).

[0040] The fungus A. alternata was cultured in a similar way to Example 4 with the difference that different concentrations of carvacrol were used in the medium and 25 that a constant concentration of copper oxychloride (5 ppm) was used throughout. The 24 hour optical density of the culture was measured and the results are shown in Table VI.

TABLE-US-00006 TABLE VI Inhibition of A. alternata by the composition according to this invention (Carvacrol + copper oxychloride) Copper 5 5 5 5 5 oxychloride concen- tration (ppm) Carvacrol 1 3.1 10 31 100 concen- tration (ppm) Inhibition 1.4 ? 13 26.0 ? 12 34.7 ? 14 53.2 ? 12 85.7 ? 3.6 (%) ? SD

[0041] As will be seen, a carvacrol concentration of 35 ppm and 5 ppm of copper oxychloride inhibit the growth of A. alternata by more than 50%, while carvacrol alone in that concentration provides 27% inhibition and copper oxychloride only 10%.

Example 7

[0042] Inhibition of the fungus Penicillium digitatum by KHCO.sub.3 alone.

[0043] The fungus Penicillium digitatum was cultured in a similar way to Example 1. The 24 hour optical density of the culture was measured and the results are shown in Table VII.

TABLE-US-00007 TABLE VII Inhibition of P. digitatum by KHCO.sub.3. KHCO.sub.3 concentration (mM) 10 20 30 40 50 Inhibition 19.4 ? 2.9 19.1 ? 10 19.6 ? 8.9 19.8 ? 2.2 21.9 ? 6.6 (% ? SD)

[0044] As will be seen, the same degree of inhibition is obtained for different KHCO.sub.3 concentrations.

Example 8

[0045] Inhibition of the fungus Penicillium digitatum by Thymol alone.

[0046] The fungus P. digitatum was cultured in a similar way to Example 1 with the difference that different concentrations of thymol, a compound isolated from thyme oil, were used in the medium. The 24 hour optical density of the culture was measured and the results are shown in Table VIII.

TABLE-US-00008 TABLE VIII Inhibition of P. digitatum by Thymol alone Thymol concentration (ppm) 0.31 1 3.1 10 31 100 310 Inhibition (%) ? 28.2 ? 3.9 24.2 ? 6.0 36.3 ? 2.3 36.2 ? 2.0 50.7 ? 2.0 78.3 ? 2.2 95.6 ? 0.5 SD

Example 9

[0047] Inhibition of the fungus Penicillium digitatum by the composition according to this invention (KHCO.sub.3+Thymol).

[0048] The fungus P. digitatum was cultured in a similar way to Example 7 with the difference that different concentrations of thymol were used in the medium and that a constant concentration of KHCO.sub.3 (30 mM) was used throughout. The 24 hour optical density of the culture was measured and the results are shown in Table IX.

TABLE-US-00009 TABLE IX Inhibition of P. digitatum by the composition according to this invention (KHCO.sub.3 + Thymol) KHCO.sub.3 concentration (mM) 30 30 30 30 30 30 Thymol 0.31 1 3.1 10 31 100 concentration (ppm) Inhibition 58.0 ? 2.1 62.9 ? 8.4 47.1 ? 3.7 56.4 ? 3.7 75.5 ? 1.9 92.6 ? 1.6 (%) ? SD

[0049] It will be seen how the results are improved by adding thymol to KHCO.sub.3. With 31 ppm of thymol only 50% inhibition is achieved, and with 30 mM of KHCO.sub.3 20% inhibition is achieved. However when the two compounds are combined inhibition of growth of the fungus P. digitatum is increased up to some 75%.