GB2207053A - Herbicidal and siccative agent - Google Patents

Abstract

The present invention provides a herbicidal and siccative agent which, in addition to conventional adjuvant and carrier materials, contains 3,5-dibromo-4-hydroxybenzonitrile (I), dibutyl 1-butylaminocyclohexanephosphonate (II) and 2-methylthio-4-ethylamino-6-isopropylamino-1,3,5-triazine (III). The present invention also provides a method of treating crops which comprises applying the above agent to crops.

Description

2207053 Herbicidal and siccative agent The present invention is concerned

with a new combination of known herbicidally-active materials for siccation or drying out and for combating 5 undesired plant growth.

The chemical pre-harvesting drying-out of cultivated plant stocks is of great importance in the scope of using modern agrochemical production procedures. In potato cultivation, besides a killing off and drying of the potato plant tops, an improvement of "e quality of the harvested product is to be achieved. In the cultivation of seed-bearing stocks, especially under wet weather conditions, a drying-out and uniform ripening is aimed for in order to make possible the use of modern harvesting techniques and to reduce the energy requirements for post-drying.

Commercially available preparations for siccation contain, for example, sodium chlorate, dinitro-o-cresol, 1,11-ethylene-2,21-dipyridylium bromide or dibutyl 1- butylamino-cyclohexanephosphonate as active material.

0 However, in the case of use in the amounts conventionally employed in practice, these preparations display a number of defects, including too high a general toxicity, a high persistency and too large amounts used.

The active materials 3,5-dibromo-4-hydroxybenzonitrile (German Democratic Republic Patent Specification No. 33,344), dibutyl 1butylaminocyclohexanephosphonate (German Democratic Republic Patent Specification No. 80,586) and 2-methylthio-4-ethylamino-6-isopropylamino-

1,3,5-triazine (Federal Republic of Germany Patent Specification No. 1, b11,904), as well as binary mixtures of these components (German Democratic Republic Patent Specifications Nos. 100,867; 123,261 and 223, 625), have long been known as herbicides. However, under practical conditions of use, in many cases the degree of action of these mixtures is not satisfactory. It is an object of the present invention to provide improved herbicidal and siccative agents for use in modern agrochemical production procedures. 20 The present invention is based upon the task of providing an advantageous combination of active materials with herbicidal and siccative properties based upon known herbicidally-active materials which is characterised by a higher degree of effectiveness in comparison with the individual actions and thus by smaller amounts to be used which makes possible a wider field of use.

z c Thus. according to the present invention, there is provided a herbicidal and siccative agent which, in addition to conventional adjuvant and carrier materials. contains 3,5-dibromo-4-hydroxybenzonitrile (I), dibutyl 1-butylaminocyclohexanephosphonate (II) and 2-methylthio4ethylamino-6-isopropylamino-1,3,5-triazine (III).

We have found that this mixture of active materials according to the present invention has a herbicidal and siccative action which is substantially better than the expected additive activity of the individual components and of the binary combinations. Consequently, as a result of the synergistic increase of action, the amount of active material mixture to be applied can be considerably reduced.

A further advantageous action of the active material combination according to the present invention is its ability to reduce the infection of potato tubers by Phytophthora infestans.

The agent according to the present invention preferably contains the three active components in amounts of 10 to 35% by weight of 1, 55 to 85% by weight of II and 4 to 10% by weight of III, referred to the total weight of the three active components.

The combination according to the present invention is especially suitable for killing of potato tops and for drying granular legumes and rape, as well as for combating undesired plant growth. Furthermore, the 01 combination according to the present invention can be used for inhibiting plant growth in the pregermination stage or before the sprouting of cultivated plants and for inhibiting subsequent growth of weeds in agriculture and horticulture. The agent according to the present invention can also be used in the subsequent growing of weeds and in the subsequent growing of cultivated plants, especially in cereal cultures.

The active material combination according to the present invention has a low degree of toxicity. Formulations of the active material combination according to the present invention can be- "9dged in the usual way. For this purpose, they can be dissolved or dispersed in conventional adjuvant and carrier materials or mixed with solid carrier materials or formulated by other known processes.

The agent generally contains 5 to 90% by weight of active materials. The agent can be used as such or in a form of use prepared by further dilution or as tank mixture. Application can take place in the usual manner, for example by pouring, spraying or sprinkling. The a=unt of active material used for the siccation of potato and seed-bearing crops is generally from about 1. 0 to 6.0 kg./ha. When used as a herbicide, the amount of active material used is generally from about 0.5 to 3.0 kg./ha.

1 i i j i 1 1 1 1 i i 1 0 The following Examples are given for the purpose of illustrating the present invention, the three active materials thereby being designated by the above-given Roman numerals: 5 Example 1.

An emulsion concentrate of the agent according to the present invention can have the following composition: 11. 5% by weight of 1 33.5% by weight of II 5% by weight of III 5% by weight of an emulsifier-based upon an alkyl phenol with 12 ethylene oxide groups 5% by weight of a biolipid extract 40% by weight of xylene. Example 2.

Another emulsion concentrate of the agent according to the present invention can have the following composition:

8.5% by weight of I 54% by weight of II 3.5% by weight of III 13% by weight of an emulsifier based upon an alkylphenol with 12 ethylene oxide groups 21% by weight of xylene. Example 3.

Siccative action of the agent according to the present invention.

0 The siccative action of the agent according to the present invention was determined on the basis of experiments in parcels of open land using potatoes of the Karpina type.

For each variant, there was used a planted area 2 of 4 x 10 m The active material was applied by spraying with a knapsack sprayer. The amount of agent applied was 60 ml./m 2 The appraisal of the action took place after 4, 7 and 14 days, the degree of killing off of the plants being evaluated in percentages according to leaves and stalks. The calculation of the synergisti effect took place according method:

= X+ Y X X Y 1 or (X X Y) + (X X Z) + (Y X Z) XxYxz 10000 E = X+ Y+Z - + wherein X, Y and Z designate active materials.

The results obtained are set out in the following Table 1:

j i i 1 c 2 r Table 1

Siccative action of the agent according to the present invention Experiments with potatoes inparcels of o12en-land Nacio siccative action in % Synergistic effect accord 3 Ametryn ing to COLBY 50: 1 (known) 1 11 111 1+11 1+111 11+111 1+11+111 1+11 I+Ili ii+iii I+II+Iii conc.

A.S. 1.7 0.245 0.358 0.070 leaf 85 83 20 12 100 100 60 100 - 15 30.4 0 stalk 75 30 2 2 52 75 25 100 20.6 43.6 21.0 67.2 conc.

A,S. 0.092 0.268 0.040 leaf 18 12 12 45 57 41; 80 17.2 29.2 18.4 44.1 stalk 1 9 2 12 29 18 55 2.1 26.0 7.2 43.4 conc.

A.S. 0.050 0.430 0.020 leaf 15 10 5 35 46 30 72 11.5 26.8 15.5 44.8 stalk 1 4 2 11 23 13 53 6.0 20.0 7.1 46.1 A.S. = active substances 0 1 -j 1 Example 4. Residual action of the agent according to the present invention in the soil.

The determination of the residual action of the active material mixturetook place with summer wheat under greenhouse conditions with uniform watering. For each variant, 4 x 50 grains were sown at monthly intervals in plant dishes in a mixture of 70% by weight of cultivation soil and 30% by weight of sand. Before sowing, the soil mixture was sprayed with amounts of active materials givIen in the following Table 2. After 36 days, an appraisal was made of the damaging action on the leaves (leaf surface in percent). The results obtained are also given in the following Table 2:

is t Table 2

Residual action in the soil active material or damage to the leaves (leaf active material area in %) 36 days after mixture (kg. /ha. sowing sowing (in weeks) after application of active material(s) 1 5 9 13 sodium chlorate (15.0) 24 10 40 28 I+ 11 (0.6+ 1.92) 0 3 0 0 I+=+III (0.6+1.92+0.12) 0 2 0 0 i v i i i i 1 i 1 i 1 j 1 i i 1 i 1 1 L1 -gExample 5. Action of the agent according to the present invention on Phytophthera infestans.

The action of the active material mixture according to the present invention on Phytophthera infestans was determined in a laboratory experiment. 40 cubes of potato tuber tissue (Astilla type) (length of edge 1.5 cm.) were infected with a zoospore suspension of Phytophthera infestans and, after 24 hours, dipped into a solution of the active material combination according to the present invention. The control was treated with water. The potato tissue cubep- y?i!r-- kept in a moisture chamber at 17 0 C. Appraisal took place 10 days after infection by determining the number of infected sides or by determining the degree of infection according to the following appraisal scheme: 0 no effect 1 weak effect 2 up to 30% effect 3 up to 50% effect 4 up to 8M. effect 5 up to 100% effect.

The results obtained are set out in the following Table 3:

(D -10-.

Table 3

Action against Phytophthera infistans active material conc. number of degree of or active infected sides effect material mixture in % to un(appraisal) treated control sodium chlorate 2.5 91 3 (known) 1,11-ethylene 2,2'-dipyridylium 0.5 68 3 dibromide (known) 1 + II (known) 0.6+ 1.92 12 1 1 + 11 + 111 0.6+ 1.92 5 0 + 0.12 J Example 6.

Selective herbicidal action of the agent according to the present invention.

The-herbicidal action was tested on a-variety of weeds and cultivated plants. The plants were grown on cultivation soil in plastic dishes under climatised conditions (20 0 C.). The application of the agent according to the present invention took place in the subsequent growth stage by spraying on. At this stage, the plants were two weeks old in the case of Avena sativa, Zea mays and Sinapis alba and three weeks old in the case of Lolium perenne, Echinochloa crus-galli. Chenopodium album, Apera ApLca-venti, Stellaria media and Gallium aparine. The herbicidal action was appraised in percentage damage of the plants or plant stock (necroses, chloroses and growth inhibition) 14 days i i j t 1 1 1.

i 1 i i f i i j i i f' 1 is after application of the agent according to the present invention, said agent containing, by weight, 6% of 1, 38% of II and 2.4% of III. The agent was used in the following amounts:

A - 0.25 1./ha. SOEC B - 0.50 1./ha. 50 EC C - 0.75 1./ha. 50 EC The results obtained are set out in the following Table 4:

Table 4

Selective herbicidal action plant damage to the plants (in %) 14 days after application of the agent A B C Avena sativa 3 30 30 Zea mays 5 10 20 Lolium Rerenne 2 10 10 Echinochloa crus-galli 10 30 80 Chenopodium album 100 100 100 Apera ca-venti 0 10 80 Stellaria media 70 90 95 Galium aparine 5 10 95 lipapis alba 80 95 100 1 ' -11

Claims (9)

Patent Claims

1. A herbicidal and siccative agent which, in addition to conventional adjuvant and carrier materials, contains 3,5-dibromo-4hydroxybenzonitrile (I), dibutyl 1-butyl5 aminocyclohexanephosphonate (II) and 2-methylthio-4ethylamino-6-isopropylamino-1,3,5-triazine (III).

2. An agent according to claim 1, wherein the three active materials are present in amounts of from 10 to 35% by weight of 1, 55 to 85% by weight of II and 4 to 10% by weight of III, referred to the total weight of the three active materials.

3. An agent according to-c-lai-m-l--or 2, wherein it is in the form-of a solution or dispersion or of a solid mixture.

4. An agent accordinr to any of the preceding claims, wherein it contains

5 to 90% by weight of the active materials. 5. An agent according to claim 1, substantially as hereinbefore described and exemplified.

6. A method of drying out potato and seed-bearing crops, wherein an agent according to any of claims 1 to 5 is applied in an amount of from 1.0 to 6.0 kg./ha.

7. A method of destroying weeds, wherein an agent according to any of claims 1 to 6 is applied in an amount of from 0.5 to 3.0 kg./ha.

8. A method according to claim 6 or 7, wherein application is by pouring, spraying or sprinkling.

i i i 1 i 1 1 c1 l

9. A method of treating crops according to any of claims 6 to 8, substantially as hereinbefore described and ex"lified.

Published 1988 at The Patent Office. Stew House. 66.71 High holborn, London WC1R 4TP. may be obtained from The Patent Office, Sales Branch, St Mary Cray. Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. 1 187.