MIXTURES CONTAINING SECONDARY CALCIUM AND MAGNESIUM PHOSPHONATE AND THEIR USE AS FUNGICIDE OR FERTILIZER

Abstract

The present invention relates to the use of mixtures containing secondary calcium and secondary magnesium phosphonate for combatting harmful fungi, to the use thereof as fertilizer or plant nutrient, to a mixture, containing secondary calcium and secondary magnesium phosphonate in a specific molar ratio, characterized in that the solid form of the mixture has a water solubility of at most 5 g/l, and to a method for preparing a mixture containing secondary calcium phosphonate and secondary magnesium phosphonate.

Claims

1-17. (canceled)

18. A method for combatting harmful fungi, wherein the fungi, their habitat or the materials or plants to be protected against fungal attack, or soil in which the plants grow or are to grow or plant propagation material are treated with an effective amount of a phosphonate A or of a mixture of phosphonate A and a phosphonate B; where phosphonate A is a mixture of secondary calcium phosphonate and secondary magnesium phosphonate, and phosphonate B is selected from the group consisting of primary calcium phosphonate, primary magnesium phosphonate, secondary potassium phosphonate, primary potassium phosphonate, primary ammonium phosphonate and mixtures thereof.

19. The method as claimed in claim 18, where the molar ratio of calcium phosphonate in phosphonate A and in phosphonate B, if present, to magnesium phosphonate in phosphonate A and in phosphonate B, if present, is of from 10:1 to 1:10.

20. The method as claimed in claim 19, where the molar ratio of calcium phosphonate in phosphonate A and in phosphonate B, if present, to magnesium phosphonate in phosphonate A and in phosphonate B, if present, is of from 2:1 to 1:2.

21. The method as claimed in claim 20, where the molar ratio of calcium phosphonate in phosphonate A and in phosphonate B, if present, to magnesium phosphonate in phosphonate A and in phosphonate B, if present, is of from 1.5:1 to 1:1.5.

22. The method as claimed in claim 18, where a mixture of phosphonate A and phosphonate B is used, where the weight ratio of the overall amount of phosphonate A to the overall amount of phosphonate B is of from 100:1 to 1:1.

23. The method as claimed in claim 21, where the weight ratio of the overall amount of phosphonate A to the overall amount of phosphonate B is of from 10:1 to 1.5:1.

24. The method as claimed in claim 18, where the phosphonate is used as an aqueous dispersion.

25. The method as claimed in claim 18, for combatting phytopathogenic fungi.

26. The method as claimed in claim 25, for combatting foliar phytopathogenic fungi, soilborne fungi and/or seed pathogens.

27. The method as claimed in claim 18, for combatting fungi selected from the group consisting of Ascomycetes, Oomycetes, Deuteromycetes and Zygomycetes.

28. The method as claimed in claim 27, for combatting Ascomycetes.

29. The method as claimed in claim 27, for combatting fungi of the order Erysiphales and/or of the genus Rhizopus.

30. The method as claimed in claim 29, for combatting Erysiphe necator, Erysiphe graminis, Erysiphe cichoracearum, Sphaerotheca fuliginea and/or Rhizopus stolonifer.

31. The method as claimed in claim 27, for combatting Oomycetes.

32. The method as claimed in claim 31, for combatting fungi of the genus Plasmopara.

33. A mixture containing secondary calcium phosphonate and secondary magnesium phosphonate, where the molar ratio of secondary calcium phosphonate to secondary magnesium phosphonate is of from 1:10 to 10:1; characterized in that the solid form of the mixture has a water solubility of at most 5 g/l at 20 C.

34. A method for preparing a mixture containing secondary calcium phosphonate and secondary magnesium phosphonate, comprising reacting dolomite with phosphonic acid or with a primary phosphonate.

35. The method as claimed in claim 34, where dolomite is selected from dolomite in the proper sense, dolomite in partially calcinated form, dolomite in fully calcinated form and mixtures thereof.

36. The method as claimed in claim 34, where dolomite and phosphonic acid are used in a molar ratio of from 1:1 to 1:4, and dolomite and the primary phosphonate are used in a molar ratio of from 1:2 to 1:8.

37. The method as claimed in claim 34, where dolomite and phosphonic acid or the primary phosphonate or the mixture thereof are reacted with each other by either (1.1) providing an aqueous dispersion of dolomite and (2.1) adding thereto the phosphonic acid or the primary phosphonate or a mixture thereof, where the phosphonic acid or the primary phosphonate or their mixture is added either in pure form or as an aqueous solution; or by (1.2) providing an aqueous solution of phosphonic acid or the primary phosphonate or a mixture thereof and (2.2) adding thereto dolomite, either in pure form or as an aqueous dispersion, or by (1.3) providing an aqueous medium and then (2.3) adding simultaneously the phosphonic acid or the primary phosphonate or a mixture thereof and dolomite, where the phosphonic acid or the primary phosphonate or their mixture and/or dolomite are added either in pure form or as an aqueous solution or dispersion.

Description

[0140] The invention is now illustrated by the following examples and figures.

FIGURES

[0141] FIG. 1 shows leaves of vine grapes of the variety Mller-Thurgau 8 days after infection with Uncinula necator (see example B.2). 1 is the leaves treated with the suspension of example 1, and 2 is the untreated control.

[0142] FIG. 2 shows wheat plants of the variety Kanzler 8 days after infection with Erysiphe graminis (see example B.3). 1 is the plants treated with the suspension of example 1, and 2 is the untreated control.

[0143] FIG. 3 shows slices of Pumpernickel one week after inoculation with Rhizopus stolonifer. 1 is the water-treated control slice, 2 is the slice treated with the mixture of example 8 (1:50 dilution), 3 is the slice treated with the mixture of example 1 (1:50 dilution) and 4 is the slice treated with sorbic acid, a standard preservative (see example B.4). Remark to the slice treated with the mixture of example 1: the whitish glint is due to the higher content of particles compared with example 8.

EXAMPLES

A. Synthetic Examples

[0144] Dolomite powder, partially calcinated dolomite and fully calcinated dolomite were obtained from Dolomitwerk Jettenberg, Germany. Phosphonic acid was obtained from ICL-IP Bitterfeld-Wolfen, Germany. In examples B, in each case, 0.2 g of the defoamer Silwet L-77 was added. The water used was demineralized water.

Example 1

[0145] 14.4 g (0.1 mol) of partially calcinated dolomite with a particle size of <0.5 mm were slowly suspended into 70 ml of water. Then 16.4 g (0.2 mol) of crystalline phosphonic acid were added within 1 h at such a rate that the temperature did not exceed 70 C. The mixture was stirred overnight to give a stirrable white suspension with a pH of 4.8.

Example 2

[0146] 10 g (0.05 mol) of dolomite powder with a particle size of 20 m were suspended into 50 ml of water. Then 9.02 g (0.11 mol) of crystalline phosphonic acid were added at such a rate that the foam formation was controllable. A white suspension with a pH of 6.5 was obtained.

Example 3

[0147] 44.6 g (0.54 mol) of phosphonic acid were dissolved in 110 ml of water. Then 50 g (0.27 mol) of dolomite powder were added. The mixture was stirred overnight to give a white suspension with a pH of 7.

Example 4

[0148] 66.9 g (0.81 mol) of phosphonic acid were dissolved in 110 ml of water. Then 50 g (0.27 mol) of dolomite powder were added. The mixture was stirred overnight to give a stirrable white suspension with a pH of 5.2.

Example 5

[0149] 89 g (1.1 mol) of phosphonic acid were dissolved in 110 ml of water. Then 50 g (0.27 mol) of dolomite powder were added. The mixture was stirred overnight to give a stirrable white suspension with a pH of 3.6.

Example 6

[0150] 44.1 g (0.54 mol) of phosphonic acid were dissolved in 110 ml of water. Then 39.3 g (0.27 mol) of partially calcinated dolomite powder were added. The mixture was stirred overnight to give a stirrable white suspension with a pH of 4.5.

Example 7

[0151] 44.1 g (0.54 mol) of phosphonic acid were dissolved in 110 ml of water. Then 25.9 g (0.27 mol) of fully calcinated dolomite were added. The mixture was stirred overnight to give a stirrable white suspension with a pH of 6.

Example 8

[0152] 66.9 g (0.81 mol) of phosphonic acid were dissolved in 110 ml of water. Then 25.9 g (0.27 mol) of fully calcinated dolomite were added within 60 min. The mixture was stirred overnight to give a stirrable white suspension with a pH of 4.8.

Example 9

[0153] 25.9 g (0.27 ml) of fully calcinated dolomite were dissolved in 110 ml of water. Then 66.9 g (0.81 mol) of phosphonic acid were added within 60 min. The mixture was stirred overnight to give a stirrable white suspension with a pH of 5.

Example 10

[0154] 88.2 g (1.1 mol) of phosphonic acid were dissolved in 110 ml of water. Then 25.9 g (0.27 mol) of fully calcinated dolomite were added within 60 min. The mixture was stirred overnight to give a stirrable white suspension with a pH of 2.

Example 11

[0155] To the suspension of example 10, 60.48 g of an aqueous 50% KOH solution was added portionwise at such a rate that the temperature did not exceed 50 C. A white, cream-like product with pH 5.3 was obtained.

Example 12

[0156] To a 30% by weight aqueous solution of 10 mol of phosphonic acid were added 4 mol of Dolomit DJ (very pure, fully calcinated dolomite with equimolar amounts of Ca oxide and Mg oxide) from Dolomitwerk Jettenberg Schndorfer GmbH, Germany within 30 min. Then, a suspension of 3,5 mol of Dolomit DJ in 600 ml of water were added within 60 min. Both addition steps were carried out under cooling to keep the temperature below 60 C. The mixture was stirred for 6 h to give a finely dispersed suspension with a pH of 3.

Example 13 (For Comparison)

[0157] To a 30% by weight aqueous solution of 10 mol of phosphonic acid were added 7.5 mol of magnesium carbonate within 30 min; the temperature was below 60 C. Then, 600 ml of water were added. The mixture was stirred for 6 h to give a finely dispersed suspension with a pH of 3-4.

Example 14 (For Comparison)

[0158] To a 30% by weight aqueous solution of 10 mol of phosphonic acid were added 7.5 mol of calcium carbonate within 30 min; the temperature was below 60 C. Then, 600 ml of water were added. The mixture was stirred for 6 h to give a finely dispersed suspension with a pH of 3-4.

B. Biological Examples

[0159] The reaction mixture obtained in example 1 was diluted with water in 1:50 v/v ratio, then 0.025% Silwet L-77 was added.

[0160] B.1 Protective Action Against Sphaerotheca fuliginea in Cucumber

[0161] The two fully developed primary leaves of Trichosanthes cucumerina were sprayed with the above mixture to run-off point.

[0162] For comparative reasons, the two fully developed primary leaves of other Trichosanthes cucumerina plants were treated with VeriPhos from Kwizda Agro, Austria, containing a mixture of primary potassium phosphonate and dipotassium phosphate (KH.sub.2PO.sub.3/K.sub.2HPO.sub.4). Dilution was calculated to finally result in the same molar concentration of phosphonate like example 1.

[0163] The next day, the plants were inoculated with conidia of Sphaerotheca fuliginea.

[0164] Eight days after application, the extent of infection was determined and the efficacy W was calculated from the infected leave surface according to Abbot's formula:

W=(1/)100

corresponds to the infection of the treated plants in % and to the infection of the untreated (control) plants in %.

[0165] When efficacy is 0, the degree of infection corresponds to that of untreated plants, while an efficacy of 100 means no infection.

[0166] The results are compiled in table 1

TABLE-US-00001 TABLE 1 Treatment Efficacy (control) 0 VeriPhos (comparative) 56 Mixture of example 1 86

[0167] B.2 Protective Action Against Uncinula necator in Vine Grapes

[0168] Leaves of vine grapes of the variety Mller-Thurgau sprout with 6 to 10 fully developed leaves were treated in analogy to example B.1. The results are compiled in table 2 and shown in FIG. 1.

TABLE-US-00002 TABLE 2 Treatment Efficacy (control) 0 Mixture of example 1 100

[0169] B.3 Protective Action Against Erysiphe graminis in wheat

[0170] Pots with wheat plants of the variety Kanzler (first two leaves developed) were treated in analogy to example B.1. The results are compiled in table 3 and shown in FIG. 2.

TABLE-US-00003 TABLE 3 Treatment Efficacy (control) 0 Mixture of example 1 83

[0171] Analogous results were obtained with the reaction products of examples 2 to 11.

[0172] B.4 Protective Action Against Rhizopus stolonifer on Rye Bread (Pumpernickel)

[0173] Sterile slices of Pumpernickel were each sprayed with water (control), a 0.1% sorbic acid solution (a standard preservative) or the mixture of example 1 or of example 8 (1:50 diluted with water). For inoculation with the fungus, small disks of blotting paper were soaked with a spore suspension of Rhizopus stolonifer and placed onto the center of Pumpernickel slices. After one week of incubation, the degree of fungus formation was examined. The results are compiled in table 4 and shown in FIG. 3.

TABLE-US-00004 TABLE 4 Treatment Infected surface area [%] (control) 80 Mixture of example 1 <5 Mixture of example 8 <5 Sorbic acid 40

[0174] As can be seen, the fungus grew abundantly on the untreated control bread slice, while the slices treated according to the invention showed virtually no infection.

[0175] B.5 Effect Against Plasmopara viticola in Grapevines

[0176] Potted grapevines were inoculated with Plasmopara viticola both before foliar treatment with the active agent and after washing the active agent coating off the leaves in order to test the effect of the residual depot of actives. To ensure a good comparability of the results and avoid or at least strongly minimize falsification of the effects, e.g. due to the use of leaves of different physiological age or of different expositions, a half-leaf treatment was carried out: In each case only one half of a leaf was treated, while the other half remained untreated and served as a control and reference for determining efficacy; the two halves being separated by the middle leaf vein. For this purpose a precision sprayer was used for applying the active compounds on the one leaf half, while the half which was to stay untreated was covered with a blotting paper during spraying. The active compounds are not volatile and thus can be expected not migrate from one half onto the other via vapor phase. Due to principles of plant physiology there is also no significant internal transport between leaf areas separated by the middle leaf vein.

[0177] B.5.1 Protective and Curative Treatment against Plasmopara viticola

[0178] For a treatment according to the invention, the reaction mixture obtained in example 12 was diluted with water in 1:100 v/v ratio, then 0.05% Silwet L-77 was added. For comparison, the reaction mixtures obtained in examples 13 and 14, respectively, were diluted with water in 1:200 v/v ratio, then 0.05% Silwet L-77 was added.

[0179] In a greenhouse, potted grapevine plants (shoots with 10-14 leaves), were inoculated with a freshly prepared aqueous spore suspension of Plasmopara viticola (410.sup.4 cell/ml; 50 l of suspension sprayed per leaf). The plants were kept for 12 h in a humid chamber.

[0180] Then the plants were subjected to a half-leaf treatment by applying either a suspension of the product of example 13 containing secondary magnesium phosphonate, or of the product of example 14 containing secondary calcium phosphonate, or of the product of example 12 containing secondary calcium and magnesium phosphonate; in each case diluted and supplemented with a wetting agent as defined above. The application rate was in each case ca. 2 l/cm.sup.2. After 24 h the plants were washed by immersion into water and after drying subjected to a second inoculation with the above-described aqueous spore suspension of Plasmopara viticola.

[0181] 6 days after the first inoculation the plants were placed for 12 h into a humid chamber and then the extent of infection was determined visually and the efficacy W was calculated from the infected leave surface according to the above Abbot's formula.

[0182] The expected efficacies for active compound combinations (i.e. secondary magnesium and calcium phosphonate) were determined using Colby's formula (Colby, S. R., Calculating synergistic and antagonistic responses of herbicide combinations, Weeds, 15, pp. 20-22, 1967) and compared to the observed efficacies.

Colby's formula: E=x+yx.Math.y/100

[0183] E expected efficacy, expressed in % of the untreated control, when using the mixture of the active compounds A and B at the concentrations a and b

[0184] x efficacy, expressed in % of the untreated control, when using the active compound A at the concentration a

[0185] y efficacy, expressed in % of the untreated control, when using the active compound B at the concentration b

TABLE-US-00005 Calculated Observed Active compound efficacy* [%] efficacy [%] Mg phosphonate of example 13 16.5 Ca phosphonate of example 14 24.6 Ca/Mg phosphonate of example 12 37.1 80 *according to Colby

[0186] As can be seen from the results, the mixture according to the invention has a synergistic effect.

[0187] B.5.2 Curative Treatment Against Plasmopara viticola

[0188] The experiment was carried out in analogy to B.5.1, however without the second inoculation. 5 days after the inoculation the plants were placed for 12 h into a humid chamber and then the extent of infection was determined visually and the efficacy W was calculated from the infected leave surface according to Abbot's formula. The expected efficacies for active compound combinations (i.e. secondary magnesium and calcium phosphonate) were determined using Colby's formula.

TABLE-US-00006 Calculated Observed Active compound efficacy* [%] efficacy [%] Mg phosphonate of example 13 47.3 Ca phosphonate of example 14 18.3 Ca/Mg phosphonate of example 12 56.9 92.3 *according to Colby

[0189] B.5.3 Protective Treatment Against Plasmopara viticola

[0190] The experiment was carried out in analogy to B.5.1, however without the first inoculation. 5 days after the inoculation the plants were placed for 12 h into a humid chamber and then the extent of infection was determined visually and the efficacy W was calculated from the infected leave surface according to Abbot's formula. The expected efficacies for active compound combinations (i.e. secondary magnesium and calcium phosphonate) were determined using Colby's formula.

TABLE-US-00007 Calculated Observed Active compound efficacy* [%] efficacy [%] Mg phosphonate of example 13 44.5 Ca phosphonate of example 14 35.1 Ca/Mg phosphonate of example 12 64.0 97.6 *according to Colby

[0191] B.6 Protective Treatment Against Erysiphe graminis in Wheat

[0192] In a greenhouse, wheat plants of the cultivar Kanzler with 2-3 fully developed leaves were sprayed to runoff-point with either a suspension of the product of example 13 containing secondary magnesium phosphonate, or of the product of example 14 containing secondary calcium phosphonate, or of the product of example 12 containing secondary calcium and magnesium phosphonate; in each case diluted and supplemented with a wetting agent as defined in example B.5.1. After 24 h the plants were inoculated with conidia of Erysiphe graminis. 18 days after the treatment with the active compounds the extent of infection (formation of conidia) was determined visually and the efficacy W was calculated from the infected leave surface according to Abbot's formula. The expected efficacies for active compound combinations (i.e. secondary magnesium and calcium phosphonate) were determined using Colby's formula.

TABLE-US-00008 Calculated Observed Active compound efficacy* [%] efficacy [%] Mg phosphonate of example 13 36.7 Ca phosphonate of example 14 11.7 Ca/Mg phosphonate of example 12 44.1 73.3 *according to Colby

[0193] B.7 Protective Treatment Against Sphaerotheca fuliginea and Erysiphe cichoracearum in Cucumber

[0194] In a greenhouse, leaves of Cucumis sativus plants var. Chinesische Schlangengurke were subjected to a half-leaf treatment as described in B.5 with either a suspension of the product of example 13 containing secondary magnesium phosphonate, or of the product of example 14 containing secondary calcium phosphonate, or of the product of example 12 containing secondary calcium and magnesium phosphonate; in each case diluted and supplemented with a wetting agent as defined in example B.5.1. After 24 h the plants were inoculated with mixed conidia of Sphaerotheca fuliginea and Erysiphe cichoracearum. 18 days after the treatment with the active compounds the extent of infection (formation of conidia) was determined visually and the efficacy W was calculated from the infected leave surface according to Abbot's formula. The expected efficacies for active compound combinations (i.e. secondary magnesium and calcium phosphonate) were determined using Colby's formula.

TABLE-US-00009 Calculated Observed Active compound efficacy* [%] efficacy [%] Mg phosphonate of example 13 43.3 Ca phosphonate of example 14 20.0 Ca/Mg phosphonate of example 12 54.7 86.7 *according to Colby