DK152661B - PROCEDURE FOR TREATMENT OR PREVENTION OF PLANT FUNGUS INFECTIONS AND FUNGICID PREPARATION FOR USING THE PROCEDURE - Google Patents

Description

in

DK 152661 B

The present invention relates to a method for treating or preventing fungal infections on plants and to a fungicidal composition for use in the method.

British Patent Specification No. 1,218,623 discloses, inter alia, a number of pyrimidine methanols which are useful in controlling fungi that attack plants.

It has now been found that two of these pyrimidine methanols, namely α- (2-chlorophenyl) -α- (4-chlorophenyl) -5-pyrimidine methanol (known by the generic name "fenarimol") and α- (2-chlorophenyl) -a- (4-fluorophenyl) -5-10 pyrimidine methanol (known by the generic name "nuarimol") is particularly active in controlling fungi that are pathogenic to fruits such as apples. Furthermore, it has been surprisingly found that when used with captan, these pyrimidine methanols are particularly active against the organisms Uromvce's phaseoli var. tvpica, Venturia inaeaualis and 15 Puccinia recondita. The compositions of the invention exhibit a synergistic effect in controlling these organisms, i.e. that the fungicidal effect of the combination is greater than the additive effect of the components, calculated using the well-known "Colby equation", see Weeds 15, 20-22 (1967). The compositions of the invention are also valuable in controlling mildew fPodosphaera leucotrichah

Thus, the present invention provides a method for treating or preventing fungal infections on plants which is characterized by the application of the plant (a) to a pyrimidine methanol of the general formula (I):

Cl OH

{C / - \ - (O) —x (i) 30 o

N ^ N

Wherein X represents a chlorine or fluorine atom, or a non-phytotoxic acid addition salt thereof; (b) captan (3a, 4, 7, 7a-tetrahydro-N- (trichloromethanesulphenyl) phthalimide) and (c) one or more non-phytotoxic carriers.

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The invention further provides a fungicidal composition for use in the above process which is characterized in that it is in the form of (a) a pyrimidine methanol of the general formula (I):

5 .Cl OH

{Cy @ —x <u "o

Nwn 15 wherein X represents a chlorine or fluorine atom, or a non-phytotoxic acid addition salt thereof; (b) captan (3a, 4, 7, 7a-tetrahydro-N- (trichloromethanesulphenyl) phthalimide) and (c) one or more non-phytotoxic carriers.

Captan is a well-known fungicide that can be used to treat 20 fungal infections on various food crops, incl. apples such as appears in U.S.A. U.S. Patent Nos. 2,553,770, 2,553,771, 2,553,776 and 2,867,562.

In a preferred embodiment, captan is used in combination with "nuarimol".

The combination used according to the invention is usually fed to the crop to be treated in such a way that the crop area is supplied from 1 to 80 g and preferably 10 to 80 g / hectare of the pyrimidine methanol and from 20 to 1200 g / hectare. It will be understood that the exact amount of active ingredient supplied will vary within 30 wide limits, depending on variables such as the cultivation density, the nature of the crop and the virulence of the potential or existing infection to be treated.

The method of the invention is particularly useful in treating apple trees for preventing or reducing the occurrence of scab (Venturia inaeoualis). In such treatment, the amount of pyrimidine methanol used is preferably from 20 to 80 g / hectare and the amount of captan is preferably from 400 to 1200 g / hectare.

The pyrimidine methanol and captan can be applied separately or together 3

DK 152661 B

on the apple trees, and the treatment will usually be repeated at intervals of 5 to 20 days, the treatment being initiated when the buds burst or later, and continued until harvest time, and the actual frequency and duration of treatment is determined by the severity of the current or expected disease. . It may also be desirable to continue treatment of the trees during the winter rest period, especially when severe infection has occurred.

When the pyrimidine methanol and captan are applied together on the plants requiring treatment, this combined treatment can be accomplished by mixing the two active ingredients in the spray tank immediately prior to use. However, it is preferred to formulate the two active ingredients together in the desired ratios of a preparation which is then simply diluted prior to use.

In either case, the dilute aqueous composition containing 15 of both active ingredients is novel and constitutes an agent of the invention. Such a composition may contain from 0.00005 to 0.007% by weight, preferably 0.0005 to 0.004% by weight, and particularly preferably 0.001 to 0.004% by weight pyrimidine methanol and from 0.001 to 0.1% by weight, preferably 0.001 to 0.06% by weight, and particularly preferred. 0.03 to 0.06% by weight of captan, traces of any surfactants, inert carriers and the like present in the concentrated preparations used to prepare the diluted preparation and water up to 100%.

Although the anti-fungal compositions of the invention can be applied to the plant to be treated by any conventional technique, such as by spraying, powdering, dipping or rinsing, it is preferred to treat the plants by spraying the above aqueous dispersion onto plants. In this mode of treatment, it is usually sufficient that the infected or exposed surfaces are thoroughly wetted with the liquid dispersion used.

As stated above, the diluted compositions of the invention can be prepared by mixing the active ingredients immediately before use or by diluting a pre-prepared co-composition of the two active ingredients. In either case, the active ingredients will usually be in the form of concentrate preparations which are so composed as to be capable of immediate dispersion or dilution in water.

In the case where the active ingredients are formulated separately, the captan component can be used in the usual commercially available 4

DK 152661 B

forms, e.g. in the form of a 50% or 83% wettable powder. Similarly, the pyrimidine methanol component may e.g. be formulated as a 4% or 10% wettable powder or as a 5% emulsifiable concentrate. In general, however, all suitable concentrate compositions 5 may be used and may contain from about 1 to approx. 90% by weight of the individual active ingredients.

In the case where the active ingredients are formulated together in concentrate formulations, the latter are novel and constitute agents of the invention. Such concentrates may contain from 5 to 90% by weight in total of the active ingredients, the latter being preferably present in a ratio of captan to pyrimidine methanol from 2: 1 to 25: 1 by weight.

The concentrate compositions of the invention usually contain the active ingredients in the amounts listed above, one or more inert carriers, and optionally one or more surfactants, thickeners, anti-freezing agents and preservatives. The concentrates may be solids, usually known as wettable powders or aqueous suspensions.

Wettable powders comprise a careful blend of the active ingredients, one or more inert carriers, and appropriate surfactants. The inert carrier can be selected from the attapulgitic species, the mont-moronite species, the diatomaceous earths, the kaolin species, the mica species, the talc species and the purified silicates. Effective surfactants can be found among the sulfonated lignins, the naphthalenesulfonates and the condensed naphthalene sulfonates, all the cool succinates, all the chylbenzenesulfonates, all the coolants, and the nonionic surfactants such as ethylene oxide addition compounds of phenol. Examples of wettable powder formulations which are within the scope of the invention are 30% by weight (a) Pyrimidine Methanol 1-15

Captan 10 - 75

Surfactant 1-10 (optionally several) 35 Inert carrier for 100

Aqueous suspensions comprise the active ingredients suspended or dissolved in water together with any desired surfactants.

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clays, thickeners, antifreeze or preservatives. Suitable surfactants may be selected from the agents mentioned above for wettable powders. Thickening agents, if used, are usually selected from suitable cellulose materials and natural rubbers, while glycols will usually be used when an antifreeze is needed. Preservatives can be selected from a wide range of materials, such as the various antibacterial agents of parabene type, phenol, o-chloro-cresol, phenylmercurin nitrate and formaldehyde. Examples of aqueous suspensions which are within the scope of the invention are% w / v

Pyrimidine Methanol 1-15

Captan 10 - 75 15 Surfactant (optionally several) 0.5 - 25

Thickener 0-3

Antifreeze 0-20

Preservative 0-1 20 Water to 100

The invention is further illustrated by the following examples.

Example 1 illustrates the preparation of wettable powders containing the combination of the invention.

25

Example 1% by weight

Nuarimol 3

Captan 60 30 Sodium! i rni nsul fona't 4

Sodium Alkyl Succinate 2

Laughs at 100

A wettable powder of the above composition was prepared.

The active ingredients were then ground and mixed with the specified components of conventional mixing equipment. The mixture is then further milled in a fluid energy mill to a size range of 1 to 10 µm, after which the mixture is re-mixed and de-aerated.

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prior to packing.

Example 2 illustrates the preparation of aqueous suspensions containing the combination of the invention.

Example 2% w / v

Fenarimol 2

Captan 40

Sodium naphthalenesulfonate 5 Sodium igninsulfonate 8

Ethylene glycol 4

Phenol 0.5

Water to 100 An aqueous suspension containing the components listed in Example 2 was prepared. Both active ingredients were dispersed, after reducing the size by conventional means, if necessary, in water containing the surfactant system, the preservative and part of the thickener. The particle size of both toxins was further reduced by liquid milling, the remaining amount of the thickener was added, allowed to hydrate, and the product diluted to volume with water.

The synergistic effect obtained by combining a pyrimidine methanol with the above formula (I) and captan is shown by the following 25 experiments.

Experiment 1

The effect of combinations of fenarimol and captan to control wheat bee frust Puccinia recondital was determined in the greenhouse using phenarimol concentrations of 10, 20 or 40 ppm in combination with 100 or 150 ppm captan. Fenarimol was also tested alone at 10, 20 or 40 ppm, as was captan alone at 100 and 150 ppm active ingredient.

Fenarimol was formulated as a 120 gram / liter (1 lb / gal) emulsifiable concentrate (1 EC) and captan as a 50% wettable powder (50 WP). The treatment solutions were prepared by diluting the fenarimol 1 EC preparation or captan 50 WP with tap water to the required concentrations.

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Wheat plants of the Monon variety were grown in plastic pots, each pot containing about 50 wheat plants. Each treatment solution was sprayed onto the plants in two plastic pots at the time the plants were seven days old, spraying continued until the solution ran off the plants. After drying, the plants were inoculated with spores of the wheat rust fungus and the pots and plants were placed in a moisture chamber for approx. 40 hours and then moved to the greenhouse to develop the disease.

Two weeks after the plants were placed in the greenhouse, the 10 were visually examined to determine the percentage of disease incidence, and this figure was converted to percentage disease control. The results are shown in the following Table I.

Table I 15

Percentage control of wheat bees adrust Captan 50 WP

20 Treatment PPM 0 100 150

Fenarimol 1EC 0 0 (60) ^ 17 17 10 58 75 (65.1)? / 95 (65.1) 20 83 100 (85.9) 100 (85.9) 25 40 94 98 (95) 99 (95 ) ly Percentage incidence of disease in untreated control group. ly The values given in parentheses are the values obtained by the previously mentioned Colby equation. As can be seen, the calculated 30 values are all substantially lower than the values obtained in practice, which shows that a synergistic effect has been achieved.

Experiment 2

Following the same procedure as described in Experiment 1, the effect of combinations of nuarimol and captan to control wheat bee adrust (Puccinia recondita) in the greenhouse was determined using nuarimol concentrations of 10, 20 or 40 ppm in combination with 100 or 150 ppm captan. Nuarimol was also studied alone at concentrations 8

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of 10, 20 or 40 ppm active ingredient, just as captan was tested alone at concentrations of 100 or 150 ppm active ingredient.

The formulations of the test compounds, alone and in combination, were prepared in the same way as in Experiment 1 using tap water as a diluent, the nuarimol containing formulations being prepared from an emulsifiable concentrate containing 90 grams / liter (0.75 lb / gal. ) nuarimol (0.75 EC) while the captan-containing formulations were prepared from a 50% wettable powder (50 WP).

The test wheat plants, of the Monon variety, were prepared and treated with the experimental chemistry potassium in the same manner as described in Experiment 1 and then inoculated with spores of the wheat rust fungus as previously described. The control group consisted of plants treated exclusively with the solvent.

Two weeks after the plants were placed in the greenhouse, 15 were visually examined to determine the percentage of disease incidence, and this number was converted to percentage disease control. The results are shown in the following Table II.

Table II

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Percentage control of wheat bees adrust Captan 50 WP

25 Treatment PPM 0 100 150

Nuarimol 0 0 (60) 1/13 13

0.75 EC

10 0 33 (13) ^ / 39 (13) 30 20 13 42 (24.3) 78 (24.3) 40 50 78 (56.5) 89 (56.5) 1 / Percent disease incidence in untreated control group.

1 / The values given in parentheses are the values obtained using the previously mentioned Colby equation. As can be seen, the calculated values are all substantially lower than the values obtained in practice, which shows that a synergistic effect has been achieved.

Claims (10)

1. A method of treatment for the treatment or prevention of fungus infections on plant species KNOWLEDGE that the plant (a) is supplied with a plant (a) of a pyrimidine drug of general formula (I): X represents that chlorine or fluorine atom, or a non-phytotoxic acid addition salt thereof; . The method of claim 1 for treating or preventing fungal infections due to one or more of the organisms Uromvce's phaseoli var. tvpica. Venturia inaeoualis and Puccinia 25 recondita. The method of claim 1 or 2 for treating or preventing fungal infections on apples. 4. A fungicide composition for use in the process according to claims 1-3, characterized in that it is in the form of (a) a pyrimidine methanol of the general formula (I): Cl 2 (C / <: - (O) - * V- / DK 152661 B wherein X represents a chlorine or fluorine atom, or a non-phytotoxic acid addition salt thereof; (b) captan (3a, 4, 7, 7a-tetrahydro-N- (trichloromethanesulfonyl) phthalimide) and 5 (c) one or more non-phytotoxic carriers. 5. A composition according to claim 4, characterized in that it contains from 0.00005 to 0.007% by weight of the pyrimidine methanol of formula (I) and from 0.001 to 0.1% by weight of captan. 6. A composition according to claim 4 or 5, characterized in that it contains from 5 to 90% by weight of active ingredients. 7. A composition according to any one of claims 4 to 6, characterized in that the ratio of captan to pyrimidine methanol is from 2: 1 to 25: 1 by weight. 8. A composition according to claim 6 or 7, characterized in that it is a wettable powder containing from 1 to 15% by weight of pyrimidine methanol, from 10 to 75% by weight of captan and from 1 to 10% by weight of surfactant. 9. A composition according to claim 6 or 7, characterized in that it is an aqueous suspension containing from 1 to 15% by weight of the pyrimidine methanol, from 10 to 75% by weight of captan, and from 0.5 to 25% by weight of surfactant. A composition according to any one of claims 4-9, characterized in that X is a fluorine atom. 25 30 35