NO871304L - Snail-FIGHTING MEDIA. - Google Patents

Description

The present invention relates to a new snail control agent, a method for producing this agent and the use of the agent to control snails.

It is already known to combat soil pests such as snails by means of material mixtures which essentially consist of active substance and precursor substance and which are produced by pelleting

of a mixture of active substance and prodrug. This remedy,

whose cross section or length amounts to 2-5 mm is generally too

large to be completely absorbed by the snails. This is a serious disadvantage in that the remaining residue breaks down in the soil, especially under the influence of moisture, and poses a potential danger to new animals in the soil, such as e.g. hunting grounds. If that

on the other hand, pesticides are used whose cross-section is less than 2 mm, then the agent collects after application - depending on the soil structure - in small soil depressions where it is hardly or not accessible to the snails.

Furthermore, it is known to use inert voluminous carrier materials, which contain active substance and prodrug on the surface, for combating pests in the soil (DE-OS 2 512 163 and DE-OS 2 512 164). Consequently, e.g. perlite grains coated with metaldehyde as a slug repellent. A disadvantage, however, is that these agents are only conditionally suitable in case of high soil moisture or rain, due to the mechanism of action of metaldehyde.

Furthermore, it is known that N-methyl-O-(3,5-dimethyl-4-methylthio-phenyl)-carbamate can be used to combat snails (K. Buchel "Pflanzenschutz und Schadlingsbekampungsmittel", Georg Thieme Verlag, 1977, page 107 and Godan "Schadschnecken und ihre Bekampfung", Ulmer 1979, page 220). The mollusc control effect of the homogenous preparations of this active substance, usually produced by pelleting, is good. The use of these products is, however, affected by the fact that the pelletized agents produced so far decompose within a relatively short time on moist soil or when exposed to rainwater and/or become covered with mold. Because of. this breakdown of the agent can cause the active substance to penetrate into the soil in an unwanted way. Furthermore, the pelleted agent goes because the decomposition lost as slug repellent.

Finally, it is known that commercially available preparations prepared on a carrier basis such as e.g. cornstalk waste or bran has a very poor resistance to rain. If agents of this type are used, the produced agglomerates are decomposed by the influence of rain into primary parts, which are often washed down into soil depressions where they are not accessible to snails by the influence of rain. A further disadvantage is that in the case of rain, at the same time as the decomposition of the agglomerates, the layer containing agent and active substance is also washed away, so that the particles still accessible to the animals do not contribute to their fight. Furthermore, the insufficient mold resistance is a disturbing feature, as here too the economic control of pulmonates is affected, which in a climate with very high humidity, generally moderate temperatures and mild winters with frequent rainfall find optimal living conditions.

It has now been found that the above-mentioned disadvantages of known snail control agents can be prevented when a snail control agent consisting of the following components is used:

A) native carrier material,

B) active substance with molluscicidal action,

C) precursor,

D) hydrolysis stable binder and

E) any additional additives.

It must also be said to be very surprising that the binder used in combination with the native carrier material, on the one hand, gives the combined snail control agent excellent rain resistance and, on the other hand, does not affect the snails' absorption of mediator and active substance.

A significant advantage of the snail control agent according to the invention is that by using the native material as a carrier, a clearly longer effect is achieved. In this way, no significant amounts of the active substance reach the soil in this way

that any beneficial animals may be harmed.

in

By combining the above-mentioned components A), B),

C), D) and possibly E) are new snail control agents available which are surprisingly superior to the known agents.

As native carrier materials A) are used in the snail control agent according to the invention preferably all native waste products such as e.g. bran, corn cob waste, coconut husk pieces, tobacco stalks, cork waste, sawdust, bark chips, etc., provided they have a solid consistency at room temperature and do not decompose rapidly when exposed to moisture. Furthermore, pellets can also be used, of e.g. corncob waste, cork waste, bark chips, etc., as carrier material.

The native carrier materials preferably have a particle size of 2-7 mm and especially of 2-4 mm.

As active substances with molluscicidal action, the known active substances are used in the snail control agents according to the invention, e.g. indicated in Godan "Schadschnecken und ihre Bekampfung", preferably active substances from the class of carbamates. The compound N-methyl-O-(3,5-dimethyl-4-methylthio-phenyl)-carbamate is particularly preferably used. It can either be used as just one active substance or a mixture of active substances.

As precursors, the snail control agents according to the invention can contain all applicable precursors that are used in such agents - i.e. precursors which are physiologically usable by snails. Preferably, ground types of flour are used, such as e.g. wheat flour, rye flour, rice starch, molasses, wheat waste, barley waste, etc. Either just one precursor or a mixture of several precursors can be used.

As a hydrolysis-stable binder, the snail control agents according to the invention preferably use organic adhesives, which in combination do not affect the snails' absorption of mediator and active substance. Furthermore, they provide a necessary stability of the agent in the presence of water, so that the above-mentioned disadvantages of known snail control agents are not expressed. Suitable binders include: methylcellulose, polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl acetate, polyvinyl ether, polyethylene glycols, polyacrylates, polyethylene oxides, natural waxes (of vegetable, animal or mineral origin), chemically modified waxes and synthetic waxes (polyethylene waxes), polymethacrylates, polypropylene glycols, sugar, dextrin, starch, alginates, lignin sulphonates, gum arabic, preferred products of rosin resin and oils, nitro varnishes and synthetic resin varnishes based on e.g. alkyd resins, chlorinated rubbers, epoxy resins, polyester resins, polyurethanes, phenolic resins, amine resins, chlorinated polypropylene, cyclorubbers and ketone resins, etc.

Particularly preferred are the following organic adhesives: methyl cellulose, polyvinyl acetate, polyvinyl pyrrolidone, polyacrylates and polymethacrylates.

Additives that can be contained in the agents according to the invention preferably include preservatives, dyes, attractants for snails, painting aids, agents that repel warm-blooded animals, as well as water and organic solvents.

As examples of any preservative present, 2-hydroxydiphenyl, sorbic acid, p-hydroxybenzaldehyde, p-hydroxybenzoic acid methyl ester, benzaldehyde, benzoic acid, p-hydroxybenzoic acid propyl ester and p-nitrophenol can be mentioned. As dyes, which may come into consideration as additives, mention may be made of inorganic pigments, such as iron oxide, titanium dioxide and ferrocyan blue and organic dyes, such as anthraquinone-,

azo and metal phthalocyanine dyes.

As substances that exert an attractive effect on snails (snail attractants), all common components suitable for this purpose can be used. Examples include plant extracts and their processed products, as well as products of animal origin.

As a painting aid, all substances that are usually used for this purpose come into question. Kaolins, clays, talc, chalk and quartz powder can preferably be mentioned.

As agents which have a repellent effect on warm-blooded animals, which exert a repellent effect on warm-blooded animals such as dogs and hedgehogs, all suitable components, which are usually used for this purpose, can be used. Examples can be mentioned of nonyl acid vanillylamide.

As organic solvents, the solvents that can be used for the production of the fighting agents come into question. Low-boiling solvents such as methanol, ethanol, butanol and methylene chloride are preferably used.

The percentage of the above-mentioned components found in the control agent according to the invention can be varied within wide ranges. The proportion of the native carrier material is generally between 30 and 70% by weight, preferably between 35 and 60% by weight. The proportion of the active substance with molluscicidal action is generally between 0.5 and 10% by weight, preferably between 1 and 8% by weight. The proportion of precursor is generally between 10 and 70% by weight, preferably between 20 and 45% by weight, the proportion of binder is generally between 0.5 and 10% by weight, preferably between 1 and 5% by weight, and the additives are optionally present in proportions between 0.5 and 20% by weight, preferably between 0.5 and 6% by weight.

In the production of the control agent according to the invention

it is necessary to use the active substance in finely divided form. It turns out that active substances with melting points above 50°C are generally used in a mixture with grinding aids in the ground state. It is also possible to use active substances at an elevated temperature in the form of melts alone or

together with inert aids, such as is growing. When using active substances with a melting point below 50°C, these active substances are generally used in admixture with sorptive setting agents alone or optionally in admixture with precursors, optionally after homogenization of the resulting mixture.

The binder is used in the production of the pesticide according to the invention directly or in the form of solutions, emulsions, dispersions or latexes. Possible diluents include water and/or organic solvents. In addition to water, low-boiling organic solvents such as methanol, ethanol, butanol and methylene chloride also come into consideration.

The snail control agent according to the invention is preferably produced by placing the native carrier material A)

in a mixture and either

a) mixes in stages with binder D), possibly in admixture with a diluent, and then with at least one active substance with molluscicidal effect B), precursor C), possibly further additives E) and possibly further binder D), possibly in the presence of a diluent,

under intense stirring, or

b) first mix with binder D), optionally in a mixture with a diluent, as well as with precursor C) and then with

at least one active substance with molluscicidal effect B), and with additional binder D), optionally in the presence of a diluent and optionally with additives E), under

intense stirring,

and the granular products thus obtained are optionally dried and optionally reprocessed in the specified manner.

In the production of the snail control agent according to the invention, calculated on the basis of the final composition, 30

to 70% by weight, preferably 35 to 60% by weight native carrier material, 0.5 to 10% by weight, preferably 1 to 8% by weight active substance with molluscicidal action, 10 to 70% by weight, preferably

20 to 45% by weight precursor, 0.5 to 10% by weight, preferably

1 to 5% by weight binder and optionally 0.5 to 20% by weight, preferably 0.5 to 6% by weight, further additives.

Method b) can optionally be varied in that the active substance with a molluscicidal effect is, for example, dispersed in melted wax and applied to the formant layer, cooled by mixing and forms a solid enveloping layer. Optionally, media can also be arranged on the carrier by means of a binder that hardens at room temperature, possibly in connection with additives. Optionally, the curing of the binder can be accelerated by UV and ionizing radiation.

In all variants, one or more active substances can be attached to the granular carrier material using one or more binders. The order in which the components are applied to the support material can be varied in any desired manner.

The method according to the invention is generally carried out at room temperature. If active substances are to be brought into contact with carriers in the form of melters or dispersions in an inert melt, then it is necessary that at least at this stage of the method work is carried out at temperatures that are above the melting point of the active substance, or above the melting range of the aid used for the purpose.

The drying temperature (methods a) and b)) can be varied within a wide range. In general, drying is done at temperatures between 20 and 70°C, preferably between 30 and 65°C. The drying can optionally be carried out under reduced pressure. Furthermore, the drying can either take place in the mixer used for coating the carrier material or in a separate drying apparatus.

The method according to the invention can either be carried out discontinuously or continuously in ordinary apparatus.

The snail control agent according to the invention is, as stated above, very well suited to combating harmful snails.

The snails include all snails with or without a snail shell that live on land, which mainly act as polyphagous pests in agriculture and horticulture. Important such pests are snails without a cochlea such as Arion rufus (large road snail),

Arion eats and other Arionidae, Limax species, further field snails, such as Deroceras reticulatum and versts from the family Limacidae,

as well as types from the family Milacidae, and also snails with a snail shell, such as e.g. of the genera Bradybaena, Cepaea, Cochlodina, Discus, Euomphalia, Galba, Helicigona, Helix, Helicella, Heli-codiscus, Lymnaea, Opeas, Vallonia and Zonitoides.

When combating pests in the soil, the amount of application can

of the control agent according to the invention is varied within a large range. In general, between 3 and 15 kg of snail control agent is used per hectare, preferably between 5 and 10 kg per hectares.

The snail control agent according to the invention can be applied by usual methods, such as e.g. by littering.

The production and use of the snail control agent according to the invention can be seen from the following examples:

I. Manufacturing examples.

Example 1

In a mixer, carefully mix 25 kg of sawdust (sieve fraction

2-4 mm) with 13 kg wheat flour, 6 kg 0.5% aqueous methyl cellulose dispersion, 1.3 kg 25% aqueous polyvinyl acetate dispersion, 50 g molasses, 95 g highly dispersed silicic acid, 200 g blue dye and 0.6 kg finely ground N-methyl -O-(3,5-dimethyl-4-methylthio-phenyl)-carbamate of the formula

at room temperature. Then a further 1.1 kg 25% is added

aqueous polyvinyl acetate dispersion and 0.6 kg of finely ground N-methyl-O-(3,5-dimethyl-4-methylthio-phenyl)-carbamate. It is mixed for a further 5 minutes and then dried in the mixer at an air temperature of a maximum of 60°C. In this way, 42 kg of a particle granulate with a filling volume of 300 ml per 100 g.

Particle diameter: 2-5 mm

Content of active ingredient: 3% by weight

Example 2

In a mixer, carefully mix 22 kg of bark chips (sieve fraction 2-4 mm) with 14 kg of wheat flour, 40 g of a preservative available under the name "Preventol A2" based on thiocarbamate, 6 kg of 0.5% aqueous methyl cellulose dispersion, 1 .2 kg of 30% aqueous polyvinyl acetate dispersion, 55 g of molasses, 100 g of highly dispersed silicic acid, 200 g of blue dye and 0.6 kg of finely ground N-methyl-O-(3,5-dimethyl-4-methylthio-phenyl)-carbamate of the formula

at room temperature. A further 1.2 kg of 30% aqueous polyvinyl acetate dispersion and 0.6 kg of finely ground N-methyl-O-(3,5-dimethyl-4-methylthio-phenyl)-carbamate are then added. It is mixed further

for 5 minutes and then dried in the mixer with an exhaust air temperature of maximum 60°C. In this way, 40 kg of particle granules are obtained with a filling volume of 380 ml per 100 g.

Particle diameter: 2-5 mm

Content of active ingredient: 3% by weight

Example 3

In a mixer, mix 25 kg of corn stalk waste (sieve fraction 2-4 mm) with 15 kg of wheat flour, 6 kg of 0.5% aqueous methyl cellulose dispersion, 1.2 kg of 25% aqueous polyvinyl acetate dispersion, 55 g of molasses, 100 g of highly dispersed silicic acid, 200 g blue dye and 0.2 kg of finely ground N-methyl-O-(3,5-dimethyl-4-methylthio-phenyl)-carbamate of the formula

at room temperature. A further 1.2 kg of 25% aqueous aqueous polyvinyl acetate dispersion and 0.36 kg of finely ground N-methyl-O-(3,5-dimethyl-4-methylthio-phenyl)-carbamate are then added. It is mixed for a further 5 minutes and then dried in the mixer at an exhaust air temperature of a maximum of 60°C. In this way, 42 kg of particle granules are obtained with a filling volume of 385 ml per 100 g.

Particle diameter: 2-5 mm

Content of active ingredient: 1.4% by weight

Example 4

In a mixer, carefully mix 25 kg of corn stalk waste (sieve fraction 2-4 mm) with 15 kg of wheat flour, 6 kg of 0.5% aqueous methyl cellulose dispersion, 1.2 kg of 25% aqueous polyvinyl acetate dispersion, 60 g of molasses, 92 g of highly dispersed silicic acid, 200 g blue dye, 1.2 kg ground metaldehyde of the formula

A further 1.2 kg of 25% aqueous polyvinyl acetate dispersion and 2.16 kg of ground metaldehyde are then added. It is mixed further for 5 minutes and dried extremely carefully under reduced pressure. In this way, 44 kg of particle granules are obtained with a filling volume of 365 ml per 100 g.

Particle diameter: 2 - 5 mm

Content of active ingredient: 8.4% by weight

II. Application examples

In the following application examples, the comparative preparations specified below were used:

(I) = Commercial snail pellets based on metaldehyde

Content of active substance: 6.7% by weight

(II) = Commercial snail granules (extruder granules) based on N-methyl-O-(3,5-diamethyl-4-methylthio-phenyl)-carbamate Content of active substance: 4% by weight

EXAMPLE A

Control of snails

Laboratory animal: Red snail (Arion rufus)

In square wooden boxes with a base area of 0.25 m<2>, the floor is covered with a 2 to 3 cm high layer of compost soil which is moistened before the start of the experiment. The preparation to be examined is then applied in the desired quantity to half of the test surface available in each box. Furthermore, two half potatoes are placed in each box in two diagonally opposite corners as extra lining. Then 10 experimental animals are placed in each box.

After 7 days, the number of dead test animals is determined and expressed

in percentage. Hereby, 0% means that no dead animals are found, while 100% indicates a complete killing of the experimental animals.

During the entire duration of the experiment, the temperature is kept at 19°C and the relative humidity at 90 to 95%.

The preparations used, amounts applied and test results are shown in the following table.

EXAMPLE B

Snail grain preparation/ resistance to weathering

In greenhouses, the desired amount of snail grain preparation for moist soil is sprinkled in each case and sprayed with water at intervals of 2 days. During the entire duration of the experiment, the temperature is kept at 19°C and the relative humidity at 90 to 95%. 7 days after the beginning of the experiment, the mold attack on the preparations is judged in accordance with the following scale:

0 = no mold attack

1 = slight mold attack

2 = strong mold attack

3 = very strong mold attack

8 days after the beginning of the experiment, the content of active substance in the preparations is determined and judged as follows: 0 = active substance completely present, or preparation not destroyed 1 = active substance washed away to an extent greater than 10%, resp. the preparation is decomposed to a lesser extent than 10% 2 = active substance is washed away to a greater extent than 10% but less than 50%, resp. the preparation is decomposed into larger

degree than 10% but less than 50%

3 = active substance is washed away to a greater extent than 50%, but less than 90%, resp. the preparation is decomposed into larger

degree than 50%, but less than 90%.

4 - active substance completely washed away, or the preparation completely decomposed.

The preparations used and test results appear from the following table.

Claims (11)

1. Slug repellent, characterized by the fact that it consists of the following components: A) Native carrier material B) Active substance with molluscicidal effect C) Precursor D) Hydrolysis-stable binder and E) Any additional additives 2. Snail control agent according to claim 1, characterized in that it contains as native carrier material native waste products from the group of bran, corncob waste, coconut shell powder, tobacco stalks, cork waste, sawdust, bark chips. 3. Snail control agent according to claims 1 to 2, characterized in that the active substance with molluscicidal action is a carbamate. 4. Snail control agent according to claims 1-3, characterized in that the active substance with molluscicidal action is N-methyl-O-(3,5-dimethyl-4-methylthio-phenyl)-carbamate. 5. Snail control agent according to claim 1, characterized in that the precursor used is a precursor from the group ground grain, rice starch, molasses, wheat waste, barley waste, wheat flour, rye flour. 6. Snail control agent according to claim 1, characterized in that the hydrolysis-stable binder is an organic adhesive. 7. Snail control agent according to claim 1, characterized in that the hydrolysis-stable binder is an organic adhesive from the group methyl cellulose, polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl acetate, polyvinyl ether, polyethylene glycols, polyacrylates, polyethylene oxides, natural wax types, (of vegetable, animal or mineral origin ), chemically modified waxes and synthetic waxes (polyethylene waxes), polymethacrylates, polypropylene glycols, sugar, dextrin, starch, alginates, lignin sulfonates, gum arabic, refined products of rosin resin and oils, nitro varnishes and synthetic resin varnishes (base: alkyd resin, chlorinated rubber compounds , epoxy resins, polyester resins, polyurethanes, phenolic resins, amine resins, chlorinated polypropylene, cyclorubber compounds, ketone resins). 8. Snail control agent according to claim 1, characterized in that it possibly contains, as further additives, one or more substances from the group of preservatives, dyes, substances that are attractive to snails, painting aids, agents that are repellent to warm-blooded animals, water, organic solvents. 9. Snail control agent according to claim 1, characterized in that it contains A) 30 to 70% by weight native carrier material, B) 0.5 to 10% by weight active substance with molluscicidal effect, C) 10 to 70% by weight precursor and D) 0.5 to 10% by weight hydrolysis-stable binder and E) 0 to 20% by weight further additives. 10. Method for the production of slug repellents, consisting of the following components: A) native carrier material, B) active substance with molluscicidal effect, C) precursor, D) hydrolysis stable binder and E) possibly further additives, characterized by placing the native carrier material A in a mixer and either a) mixes step by step with binder D), possibly in admixture with a diluent, and then with at least one active substance with molluscicidal effect B), accelerator C), possibly further additives E) and possibly further binder D), possibly in the presence of a diluent, with thorough stirring or b) first mixes with binder D), optionally in a mixture with a diluent, as well as with precursor C) and then with at least one active substance with molluscicidal effect B) and with additional binder D), optionally in a mixture with a diluent and optionally with additives E), under thorough stirring, the products thus obtained are optionally dried and possibly reprocessed by the specified method. 11. Use of snail control agents according to claims 1 to 9, for the control of snails.