DE1567035A1 - Preparations for combating weeds in cereals - Google Patents

Description

DIpWnQ. Horst Auer ^ "* · Β. ^. Β · ι

Τα% · η * αη <Νο \% telephone; 339221

Telegraph: 2-161587 a dpu d

P 15 67 035.6 My files: PHD

Philips Patentverwaltung GmbH., 2000 Hamburg 1, Mönckebergstr.

Means for combating weeds in cereals

The simultaneous control of monocotyledonous and dicotyledonous weeds in cereals is an agricultural practice frequent problem that is only imperfect with the weed control agents known to date is resolved.

The main difficulties are that either of the numerous weed species only a few, mainly the dicotyledonous ones are combated, or that in addition to the weeds also the grain at the same time is damaged to a considerable extent. From the large number of known weed killers are therefore only very few for this special application useful.

So far, the 2-chloro-4,6-bis-ethylamino-1,3t5-triazine and known under the trade name Simazin the 2,6- dichlorobenzonitrile known under the trade name Casoron is used. Unfortunately with Simazin

PHD 695

Pi / Lr - 2 -

9098U / 1735

Documents (* L7 | IAb ^ Mr.! Sentence 3 of the amendment of September 4, 1987

the application period is very short, and it is especially very early in spring when the fields are usually not yet passable due to great wetness. In addition, some are very common in cereals Weeds, such as burdock (Galium aparine) and thistle (Cirsium arvense), from 2-chloro-4,6-bis-ethylamino-1,3,5-triazine not killed, and depending on the weather conditions, there is still a risk of grain damage so great that this agent has not been officially approved at all in most countries, for example is.

2,6-dichlorobenzonitrile avoids these disadvantages largely and, above all, enables effective control of most of the weeds occurring in cereals, however, it also leaves something to be desired.

Attempts have already been made to the effect of 2,6-dichlorobenzonitrile to improve and, for example, to control weeds in rice crops, the 2,6-dichlorobenzonitrile 2-methyl-4-chlorophenoxyacetic acid or 2-methyl-4-chlorophenoxybutyric acid are added. While These well-known herbicide mixtures are said to give good results in rice crops, they have in combating the weeds occurring in cereals and also with regard to their damaging effect Grains shown to be not superior to 2,6-dichlorobenzonitrile.

This different effect is likely to affect the Completely different nature of the weeds occurring in rice, on the other hand, on the different

- 3 9098U / 173S

Surface quality, adsorption capacity and the like of rice plants on the one hand and grain on the other be due.

Surprisingly, it has now been found that through the combination of 2,6-dichlorobenzonitrile with a Compound of the general formula

CH ₃
Shark .— <\ / V- O-CH-COOH

in which R can take all free positions on the core and halogen, a methyl group or a methoxy group represents, and especially with 2- (2,4-dichlorophenoxy) propionic acid and / or 2- (4-chloro-2-methyl-phenoxy) propionic acid or their salts or esters, both a synergistic herbicidal effect on those occurring in cereals monocotyledonous and dicotyledonous weeds as well as a very significant improvement in grain tolerance of 2,6-dichlorobenzonitrile is achieved. About that In addition, this combination also increases the application period widened, which has a very advantageous effect, especially when used in practice.

These advantageous properties are particularly evident the active ingredient mixture according to the invention in combating weeds in wheat, barley and rye crops in appearance.

Optimal results are obtained when in the mixture forming the active ingredient the weight

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ratio between 2,6-dichlorobenzonitrile and the substituted phenoxypropionic acid or its salts or Esters between 1 ι 2.5 and 3.5: 1 is.

The aforementioned propionic acid derivatives are useful used in the form of their salts, in particular their alkali metal and ammonium salts (amine salts), or in the form of their esters. Of the latter, the butyl glycol ester is particularly suitable, as it is effective against weeds at both high and low levels is easily absorbed even at low temperatures and its application is little, especially when it rains being affected.

The application rate of active substance per hectare for combating the weeds is less than the sum of the application rates when using the individual components. As a rule, around 2 - 2.5 kg of active substance per hectare applied.

By the following examples the invention is explained in detail and the advantageous effect of the active compound mixtures according to the invention against various occurring in cereal crops weeds at hand of greenhouse and field trials in comparison with the known under the name Casoron as weed control) Fung medium 2,6-dichlorobenzonitrile detected.

The preparation available under the trade name Casoron H 133, which has a content of 50 % 2,6-dichlorobenzonitrile in addition to dispersants, wetting agents and adhesives as well as inert carrier material, was used to produce the active ingredient mixture according to the invention.

909844/1735

The evaluation of the test results was in all Cases made using the following evaluation schemes.

a) Phytotoxic effect on grain. Degree of damage

1 No damage 0

2 signs of damage 2.5

3 individual leaves with very little 5 damage or slight stagnation

4 Individual leaves with minor damage, 10 or moderate stagnation

5 Most leaves with minor shades of 15 " den, or moderate stagnation

6 Severe damage, but leaves did not die, 25 whole plant damaged,

or strong stunted growth

7 Most of the leaves have died 35

8 Most of the leaves have died 67.5 and several plants have also died

9 Complete destruction of the grain 100

b) Herbicidal effect on weeds efficiency and weed grasses %

1 stand free of viable weeds

2 Very occasional 97.5 weakly viable weeds

3 Occasionally weakly viable weeds

4 Only some of the weeds are still 90 viable

5 Only part of the weeds viable 85

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Efficiency

6 Significant growth disorders or significant yellowing

7 Minor stunted growth or slight yellowing

8 Beginning growth disorders or 32.5 yellowing

9 Full of weeds O

* Example 1

In the greenhouse it was 13-15 cm higher in the 1-leaf stage located winter wheat of the Breustedts Werla variety, the each test member in three plastic dishes 29 cm in diameter had been used, treated with the active ingredients listed below.

The amount of water required for applying the active ingredients was 800 l / ha, the pressure was 3 atii and the Air temperature 16-18 ° C.

The table below is for the respective means in addition to the application rates, the corresponding degree of damage of the above evaluation scheme a) indicated, with the Evaluation was carried out after 6, 12 and 18 days.

Active ingredient application rate
kg / ha Evaluation according to
6 days 12 days O 18 days r 1. untreated O 30th O 2. 2,6-dichloro
benzonitrile 2.5 12.5 O 35 3.2- (4-chloro-2-
methyl-phenoxy) - 1.6
propionic acid ester 2.5 15th 0 4th 2nd + 3rd 2.5 + 1.6 8th 20th 909844/1735

Example 2

In the greenhouse, the most common weeds in winter crops were foxtail, real chamomile and burdock in five plastic pots each with a diameter of 13 cm and with the following in detail listed active ingredients.

The amount of water required to apply the active ingredients was 800 l / ha, the pressure was 3 atmospheres and the air temperature was 18 to 21 ^° C.

The following are the further test conditions and the means used for the individual weeds together with the respective application rates, as well as the corresponding degree of effectiveness of the above evaluation scheme b).

a) Herbicidal effect on black foxtail (Alopecurus myosuroides)
2-leaf stage, height 13-16 cm

Active ingredient application rate
kg / ha 2.5 Evaluation according to
18 days 31 days 0 1. untreated 1.6 0 80 2. 2,6-dichloro
benzonitrile 1.25 + 0.8 75 70 3. Alkali salt of
2- (4-chloro-2-
-methyl-phenoxy) -
-propionic acid 2.75 65 96 4. 2. + 3. 1.25 + 1.375 87 70 5. Alkali salt of
2- (2,4-dichloro
phenoxy) propion
acid 65 97.5 6. 2. + 5 * 90

9098U / 1735

b) Herbicidal effect on real chamomile (Matricaria chamomilla) 6-8 leaf stage, height 3-4 cm

Active ingredient application rate
kg / ha untreated Evaluation according to
8 days 21 days 33 days O O 1. 2,6-dichloro-2.5
benzonitrile O 87 90 2. Alkali salt of
2- (4-chloro-2- _{Λ 6}
methyl-phenoxy) - '
propionic acid 32.5 65 65 3. 16

4. 2. + 3.

1.25 + 0.8

5. Alkali salt of 2- (2,4-dichloro-2,75 phenoxy) propionic acid

6. 2. + 5.

1.25 + 1.375

70

16

50

70

90

97.5

75

95

c) Herbicidal effect on burdock weed (Galium aparine) 2-whorl leaf stage, height 7 - 9 cm

Active ingredient application rate
kg / ha 90984 2.5 Evaluation according to
9 days 21 days 40 days 0 0 1. untreated 1.15 0 65 65 2. 2,6-dichloro
benzonitrile 0.82 + 0.76 0 92 92 3.2- (4-chloro-2-
methyl-phenoxy) -
propxonic acid ester 1.25 + 0.57 90 99 100 4. 2. + 3. 4/1735 90 99 100 5. 2. + 3. 87 - 9 -

Example 3

In the spring, the E-leaf stage (beginning of tillering) was found on each of the 25 sqm plots Winter rye and winter wheat variety Heines VII and variety Breustedts Werla together with the respective ones occurring therein Weeds, chamomile, knotweed (Polygonum spec.) And wind stalk (Apera spica venti) using the Oxford precision sprayer treated with the active ingredients and application rates listed in detail below.

The amount of water used in each case was 800 l / ha, the

Injection pressure was 2 atu. Ä

The tables below are those for an untreated control experiment and for the active ingredients 2,6-dichlorobenzonitrile, sodium salt of 2- (4-chloro-2-methyl-phenoxy) propionic acid and for the mixture consisting of equal amounts of the two aforementioned active substances, determined from three or four parallel tests Average values χ of the herbicidal activity against the three aforementioned weeds on the basis of of the evaluation scheme b) above.

Furthermore, there is also the one from three parallel experiments determined average value χ der Grainver- ι portability on the basis of the evaluation scheme a).

For all test groups, the amount of grain harvested and its moisture content is also given.

The differences that occurred in the moisture content are primarily due to the shock caused by the

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Fabric treatment is applied to the grain growth and which thereby leads to a delay in ripening.

A field trials with winter rye

I. Herbicidal Effect

No. Active ingredient application rate kg / ha

1. untreated

2. 2,6-dichlorobenzonitrile 2.5

3. Sodium salt of 2- (4-chloro

4th 2-methyl-ph
acid
2nd + 3rd enoxy; -propion- 2.5
1.25 + 1.25 chamomile Knotweed Blade of wind χ % x % χ % 1. 0 0 0 2. 93 80 90 3. 90 93 0 4th 95 96 93

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909844/1735

II. Grain tolerance and harvest

Estimated rating yield in

3 weeks kg / ha after treatment

No. χ % abc χ

1. O 2. 67.5 3. 2.5 4th 13th No. Moisture of the
prepared grain 1. 11.5 % 2. 14.5 % 3. 11.3 % 4th 12.1 96

4541 3044 4341 3979

3993 3291 3872 3719

4000 4000 3925 3975

4266 4042 4387 4232

B Outdoor trial with winter wheat variety Heines VII

I. Herbicidal Effect Active ingredient application rate kg / ha

1. untreated 2.5 2. 2,6-dichlorobenzone tril 2.5 3. Sodium salt of 2- (4-chloro-2- methyl-phenoxy) -propionic acid 1.25 + 1.25 4th 2nd + 3rd

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909844/1735

chamomile Knotweed Blade of wind χ % χ % χ % 1. O O O 2. 90 50 87 3. 75 87 0 4th 93 90 90

II. Grain tolerance and harvest

Treasure credit door
3 weeks after
treatment Yield
kg / ha humidity
of the harvested
Grain χ % X 1. 0 2705 12.5 % 2. 25th 2980 14.0 96 3. 0 3207 12.6 % 4th 8th 3975 12.8 %

Field trials with winter wheat variety Breustedts Werla

I. Herbicidal Effect

Active ingredient

1. untreated

2. 2,6-Bichlorobenzonitrile

3. Sodium salt of 2- (4-chloro-2-methyl-phenoxy) -propionic acid

4. 2. + 3.

Application rate kg / ha

2.5
2.5

1.25 + 1.25

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909844/1735

chamomile Knotweed 1567035 χ % χ% Blade of wind O 0 χ % 1. 92 75 O 2. 80 87 90 3. 95 95 15th 4th 92

II. Grain compatibility

Treasure credit door
3 weeks after
treatment Yield
kg / ha humidity
of the harvested
Grain Λ / 0 X 1. 0 2800 13.7 % 2. 28 3725 17.3 % 3. 2.5 3625 14.2 % 4th 4th 4390 15.0 %

From the above results of the greenhouse and field trials it can be seen that the herbicidal activity of a combination of the two weed control agents 2,6-dichlorobenzonitrile and sodium salts and esters of 2- (4-chloro-2-methyl-phenoxy) -propionic acid and 2- (2,4- -Dichlorophenoxy) -propionic acid on all three weeds is much better than when the individual components of the mixture are used in double the application rate At the same time, the grain tolerance is significantly improved.

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909844/1735

The advantageous effect of the invention becomes particularly clear synergistic mixture of active ingredients the achieved weight of the harvested grain quantity. The average amount achieved during the treatment is superior both the result of the untreated parcel and the results of those parcels that only have the individual active ingredients have been treated.

Example 4

To determine the dependence of the synergistic effect on the mixing ratio of the individual components was in the greenhouse 10 cm high foxtail located in the 2-leaf stage, which is per test element in 4 plastic pots 13 cm in diameter had been used, with the active ingredients I 2,6-dichlorobenzonitrile and II 2- (4-chloro- -2-methyl-phenoxy) -propionic acid in the following mixing ratios and application rates.

The amount of water needed for the application of the active ingredients was 800 l / ha, the pressure was 3 atm, and the air temperature was 18 to 21 ⁰ C.

The evaluation was carried out according to the above evaluation scheme b.

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909844/1 735

Active ingredient II Application rate kg / ha 15th 67035 21 days (x %) f- II Evaluation according to 0 l II 1,600 14 days 32.5 1. untreated h II + 1.440 0 91.5 2. h II 0.25 + 1.280 48.5 95 3. I H l II 0.5 + 1.120 90 97.5 4th I H h II - 0.75 + 0.960 90.5 97.5 5. I H h II 1.0 + 0.800 91.5 97.5 6th I H h II 1.25 . + 0.640 91.5 96 7th I H - II 1.5 + 0.480 90 95 8th. I H _ 1.75 + 0.320 89.5 95 9. I H 2.0 + 0.160 88 90 10. IN THE 2.25 84 88 11. I H 2.5 84 12th I. 74

The above test results clearly show that even the addition of a small amount of 2- (4-chloro-2-methyl-phenoxy) propionic acid to 2,6-dichlorobenzonitrile and vice versa leads to a significant increase in effectiveness and the maximum effect is achieved when the ratio between 2,6-dichlorobenzonitrile and 2- (4-chloro-2-methyl- -phenoxy) -propionic acid is between 1: 2.5 and 3.5: 1.

The active compound mixtures according to the invention can be used in the form customary for plant growth control agents. In addition to the solution or suspension already mentioned, they can also be used, for example, as _{dusts, wettable powders t} incense cones, mixed oils, granules, etc.

Solid carrier materials include talc, dolomite, kaolin, clay, attapulgite, quartz sand, pumice stone

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9098-44 / 173-5

-, 16-

granules and, as liquid carrier materials, water, toluene, xylene, aliphatic, alicyclic and aromatic Ketones and the like.

The agents according to the invention can also contain surface-active substances, dispersants and adhesives, yes, if necessary, artificial fertilizers can also be added.

For the production of a wettable powder, for example, 50 parts by weight of the active ingredient mixture are required with 43 parts by weight of inert carrier material, e.g. B. dolomite, 5 parts by weight of sodium lignosulfonate and 2 parts by weight of sodium oleyl N-methyl taurate mixed.

A dusting agent is made, for example, by intimately mixing about 3-6 parts by weight of the active ingredient mixture obtained with 97 parts by weight of inert carrier material.

Patent claims:

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909844/1735

Claims (9)

Claims 1. Means for the simultaneous control of weeds and weeds in cereals, characterized in that that the active ingredient is a mixture of 2,6-dichlorobenzonitrile and a compound of the general formula CH ₃ Hal.-Λ A-O-CH-CO (H or their salts or esters, in which formula R can occupy all free positions on the core and halogen, a methyl group or a methoxy group represents. 2. Means according to claim 1, characterized in that that the active ingredient is a mixture of 2,6-dichlorobenzonitrile and 2- (4-chloro-2-methyl-phenoxy) propionic acid and / or 2- (2,4-dichlorophenoxy) propionic acid or their salts or esters. 3. Composition according to claims 1 or 2, characterized in that in the mixture forming the active ingredient, the weight ratio between 2,6-dichlorobenzonitrile and the substituted phenoxypropionic acid component is between 1: 2.5 and 3.5: 1. - 18 - 909844/1735 II9U9 documents 4. Composition according to claims 1 to 3, characterized in that it is in addition to the active ingredient Forming mixture and the inert carrier material contains wetting and / or dispersing agents. 5. Process for the preparation of a weed control agent, characterized in that 2,6-dichlorobenzonitrile with a compound of the general formula Hai (i λ-O-CH-COOH or their salts or esters, in which formula R can occupy all free positions on the core and halogen, represents a methyl group or a methoxy group, as well as inert support materials and optionally Wetting and / or dispersing agents is mixed. 6. The method according to claim 5, characterized in that 2,6-dichlorobenzonitrile and 2- (4-chloro-2-ethyl- -phenoxy) -propionic acid and / or 2- (2,4-dichlorophenoxy) -propionic acid or their salts or esters with an inert carrier material and optionally wetting and / or Dispersants are mixed. 7. A method for combating weeds and grass weeds in cereals, characterized in that the cereal culture with an agent according to claims 1 to is treated. - 19 -90984471735 8. The method according to claim 7, characterized in that that the grain culture per hectare with an agent containing 1 to 3 kg of active ingredient according to the claims 1 to 4 contains, is treated, 9. Means according to claim 7, characterized in that that the grain culture per hectare with an agent containing about 2 to 2.5 kg of active ingredient according to the claims 1 to 4 is treated. 9098U / 1735