DK151001B - PROCEDURE FOR TREATING FUNGUS INFECTION ON CULTURED PLANTS AND FUNGICID PREPARATION FOR USE IN PLANT PROTECTION - Google Patents

Description

151001

The present invention relates to a method of treating fungal infections on cultivated plants, especially cereals and cucurbits, and a fungicidal composition for use in plant protection.

Every year, many plants of economic and decorative importance of different fungus types are damaged. Due to the financial losses, considerable research has been carried out in an effort to find methods and materials to combat these destructive fungi.

In the specification of U.S. Patent No. 3,887,708, the use of various α, α-disubstituted-5-pyrimidine methanes and methanols, including α- (2-chlorophenyl) -α- (4-chlorophenyl) -5-pyrimidine methanol and α - (2-Chlorophenyl) -a- (4-fluorophenyl) -5-pyrimidine methanol # as plant fungicides. 2,4,5,6-tetrachloro-1,3-dicyanobenzene, also known as tetrachloroisophthalonitrile and as chlorthalonil, is disclosed in the specification of U.S. Patent Nos. 3,290,353 and 3,331,735 to be active as a plant fungicide.

It has now been found that a surprising synergistic effect is obtained in the treatment of fungus infections on cultivated plants when one of the above-mentioned pyrimidine methanols is used in combination with 2,4,5,6-tetrachloro-1,3-dicyanobenzene. .

Accordingly, the invention provides a method for treating fungus infections on cultivated plants which is characterized in that after cultivation, but before harvest, the cultivated plants are supplied with 2,4,5,6-tetrachloro-1,3-dicyanobenzene and a pyrimidine methanol of the general formula (I):

X

φ

/ Ν-Λ Y

O) Ci ° H W

N Jv ^ Cl wherein X represents chlorine or fluorine, if desired in conjunction with a non-phytotoxic, inert carrier.

The invention further provides a fungicidal composition for use in plant protection, characterized in that it contains 2,4,5,6-tetrachloro-1,3-dicyanobenzene and a pyrimidine methanol of the general formula (I):

X

Therefore, where X represents chlorine or fluorine, if desired in conjunction with a non-phytotoxic, inert carrier.

3,400,6 2,4,5,6-tetrachloro-1,3-dicyanobenzene (hereinafter abbreviated to ("DCB")) can be prepared by the procedure described in U.S. Patent No. 3,290,353 or No. 3,331,735. and the pyrimidine methanols of general formula (I) can be prepared by the process described in British Patent No. 1,218,623.

The novel combination used in the method and in the composition of the invention is surprisingly effective in controlling or controlling fungal infections such as mold and septoria on cultivated plants, especially cereals and cucurbits. In particular, the combination is particularly active against the following plant pathogens: Erysiphe graminus, Septoria nodorum, Puccinia recondita, Fusarium nivale, Puccinia gluitiarum and Pseudoperonospora cubensis.

The frequency and duration of treatment is determined by the degree of current or expected fungus infection. The components of the combination can be fed to the crop to be treated sequentially or simultaneously.

The pyrimidine methanol is preferably supplied in an amount of from 5 to 100 g per ml. per hectare, particularly advantageously 20 to 100 g per hectare. preferably DCB is supplied in an amount of from 60 to 2000 g per hectare. per hectare, particularly advantageously 50 to 2000 g per hectare. acres. Therefore, the preferred weight ratio of the pyrimidine methanol to DCB is in the range of 1: 400 to 1.6: 1. In the treatment of fungal infections, such as Puccinia recondita in cereals, weight ratios of pyrimidine methanol to DCB in the range of 1:10 to 1.6: 1 have been found to be particularly advantageous. In the treatment of fungal infections such as Pseudoperonospora cubensis in cucurbits, weight ratios of pyrimidine-methanol to DCB in the range of 1: 400 to 1:20 have been found to be particularly advantageous.

The novel combination is advantageously used in the form of a fungicidal composition containing DCB and a pyrimidine methanol of the above defined general formula (I) in conjunction with a non-phytotoxic, inert carrier.

The combination of DCB and one or the other of the pyrimidine methanols of the formula (I) defined above has been shown to produce a synergistic effect in the control of wheat leaf rust induced by Puccinia recondita and of leaf mold caused by Pseudoperonospora cubensis.

4 151001

The fungicidal composition of the invention preferably contains from 5 to 90% by weight of active ingredients and will usually be in the form of a wettable powder or powder or an aqueous suspension.

Wettable powders or powders comprise the active ingredients in close blend, one or more inert carriers and appropriate surfactants. The inert carrier may be selected from the attapulgit clays, montmorillonite clays, diatomaceous earths, kaolin species, mica species, talc and other purified silicates. Effective surfactants can be found among the sulfonated lignins, the naphthalene sulfonates and the condensed naphthalene sulfonates, the alkyl succinates, the alkylbenzenesulfonates, the alkyl sulfates, and the nonionic surfactants such as ethylene oxide addition compounds of phenol.

The following composition illustrates wettable powders which fall within the scope of the invention.

Wettable powders __.

- --— c- Weight percent

Pyrimidine Methanol 0.25 - 10 DCB 25 - 80

Surfactant (agents) 0-10

Dispersant 0-10

Anti-lumping agent 0-10

Inert materials up to 100

Aqueous suspensions contain the active ingredients suspended in water together with any desired surfactants, thickeners, antifreeze or preservatives. Suitable surfactants may be selected from those mentioned above for wettable powders. Thickening agents, if used, are usually selected from suitable cellulose materials and natural rubber, while glycols will generally be used when an antifreeze is needed. The preservatives can be selected from a wide range of materials, such as the various antibacterial agents of parabene type, phenol, o-chlorocresol, phenylmercurin nitrate and formaldehyde. Illustrative aqueous suspensions of the present invention are suspensions of the following composition:

Aqueous suspensions (fluid) Weight percent

Pyrimidine Methanol 0.2-8 DCB 20 - 60

Surfactant (agents) 0-15

Thickener 0-3

Antifreeze 0-20

Preservative 0 - 1

Anti-foaming agent 0-0.5

Water up to 100

Although the foregoing general examples suitably demonstrate to those skilled in the art the types of concentrate compositions useful in the present invention, the invention will hereinafter be further illustrated by the following specific examples. In these examples, the phenarimol compound represents α - (2-chlorophenyl) -α- (4-chlorophenyl) -5-pyrimidine methanol, and nuarimol represents the compound α- (2-chlorophenyl) -α- (4-fluorophenyl) -5- pyrimidine. Examples 1 and 2 illustrate embodiments of wettable powders in accordance with the invention, while Examples 3 and 4 relate to aqueous suspensions.

Example 1

Nuarimol 2 DCB 60

Ethoxylated nonylphenol 4 Sodium lignosulfonate 3

Silica 6

Kaolin 25

The active ingredients nuarimol and DCB are ground and then mixed with the other ingredients in conventional mixing equipment. The mixture is then ground in a fluid energy mill to a size in the range of 1 - 10 µm, and the mixture is finally mixed again and deaerated before packing.

Similarly, the following concentrate was prepared: 6 151001

Example 2

Fenarimol 2.5 DCB 50

Sodium alkyl succinate 3

Sodium lignosulfonate 3

Talc 41.5

Example 3 Weight percent

Nuarimol 2 DCB 50

Sodium naphthalene sulfonate 3

Rubber arabic 1

Propylene glycol o-chlorocresol 0.3

Water up to 100

Both active ingredients, the particle size of which is reduced in a conventional manner, if necessary, are dispersed in water containing the system of surfactant, preservative and part of the thickener. The particle size of both components is further reduced by liquid milling; the remaining amount of thickener is added, allowed to hydrate, and the product diluted to the desired volume with water.

Similarly, the following aqueous suspension was prepared: Example 4 Weight percent

Fenarimol 1 DCB 50

Ethoxylated nonylphenol 2.0

Xanthan gum 0.2

Silicone Emulsion 0.1

Water up to 100

The synergistic effect of combining the DCB and the pyrimidine methanols with the formula (I) defined above is shown by the following experiment.

7 151001

Experiment 1

The effect of combinations of DCB and α- (2-chlorophenyl) -α- (4-chlorophenyl) -5-pyrimidine methanol (hereinafter referred to as fenarimol) to control wheat leaf rust (Puccinia recondita) was determined in the greenhouse using fenarimol concentrations of 10 , 20 or 40 ppm in combination with 25, 50 or 150 ppm DCB. Fenarimol was also tested alone at 10, 20 or 40 ppm, as was DCB alone at 25, 50 and 100 ppm of active ingredient.

Fenarimol was designed as a 120 g / l (1 lb / gal) emulsifiable concentrate (1 EC), and DCB as a 75% wettable powder (75 WP). The treatment solutions were prepared by diluting the fenarimol 1 EC preparation or DCB 75 WP with tap water to the required concentrations.

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 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, they 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

Percentage control of wheat leaf DCB_

Processing PPM i0 2J5 J50 100

Fenarimol 0 () ^ 36 45 84 10 40 91 100 100 20 77 100 100 100 40 92 92 100 100

Percentage of disease in untreated control group «8 151001

Experiment 2

Using the same procedure as described in Experiment 1, the effect of combinations of α- (2-chlorophenyl) -α- (4-fluoro-phenyl) -5-pyrimidine methanol (hereinafter referred to as nuarimol) and DCB to control Puccinia recondita in the greenhouse using nuarimol concentrations of 10, 20 or 40 ppm in combination with 25, 50 or 100 ppm chlorthalonil. Nuarimol was also tested alone at concentrations of 10, 20 or 40 ppm of active ingredient, just as DCB was tested alone at concentrations of 25, 50 or 100 ppm of active ingredient.

The compositions 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 compositions being prepared from an emulsifiable concentrate containing 90g / l (0.75 lb / gal) nuarimol (0.75 EC).

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

Two weeks after the plants were placed in the greenhouse, they 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 II.

TABLE II

Percentage control of wheat leaf DCB_

Treatment PPM () _25 5 £ 100

Nuarimol 0 (36 45 84 10 4 81 93 100 20 44 100 100 100 40 79 - * 100 100 1 / Percentage of disease in untreated control group. * Not made.

Claims (5)

151001 A method of treating fungus infections on cultivated plants, characterized in that after cultivation, but before harvest, the cultivated plants are fed 2,4,5,6-tetrachloro-1,3-dicyanobenzene and a pyrimidine methanol with the general formula (I): X (é) q \ -C-OH (I) & wherein X represents chlorine or fluorine; if desired in conjunction with a non-phytotoxic, inert carrier, therefore. Method according to claim 1 for the treatment of fungus infections, such as Puccinia recondita, in cereals, characterized in that the cereal is applied after the crop emergence but before harvest. Process according to claim 1 or 2, characterized in that the weight ratio of the pyrimidine methanol to 2,4,5,6-tetrachloro-1,3-dicyanobenzene is in the range of 1: 400 to 1.6: 1. 4. Fungicide preparation for use in plant protection, characterized in that it contains 2,4,5,6-tetrachloro-1,3-dicyanobenzene and a pyrimidine methanol of the general formula (I): X 10 151001 φ / N — Λ \ (ΐ) Ν -7 ^ \ ci (Where X represents chlorine or fluorine, if desired in conjunction with a non-phytotoxic, inert carrier therefore. Fungicide preparation according to claim 4, characterized in that the weight ratio of the pyrimidine methanol to 2,4,5,6-tetrachloro-1,3-dicyanobenzene is in the range of 1: 400 to 1.6: 1.