DE2230258A1 - Means for selective weed and weed control in cereals - Google Patents

Description

The present invention relates to a new synergistic combination of active ingredients, which consists of the known 1- (2-benzthiazolyl) -1,3-dimethylurea and the also known 1- (3-chloro-4-methyl) -phenyl-3,3-dimethylurea and a particularly good herbicidal effect for selective weed and weed control in cereals having.

It has already become known that 1- (2-benzothiazolyl) -1,3-dimethylurea can be used can be used as a selective herbicide in cereals (see US Pat. No. 2,756,135 and Belgian patent 687 019). It is also known that 1- (3-chloro-4-methyl) -phenyl-3,3-dimethylurea can also be used as a selective herbicide in cereals (cf. German Offenlegungsschriften 1 905 599 and 1 966 298). However, both individual components have the disadvantage that they can be used at low application rates and concentrations the large number of weeds and grass weeds occurring in cereals do not destroy all sufficiently. If higher concentrations of one of the herbicidal agents mentioned are used, this leads to damage to the cereal species.

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It has now been found that the new combination of active ingredients (1) 1- (2-Benzthiazolyl) -1,3-dimethyl urea of the formula

NH - CH, (I)

(2) 1- (3-chloro-4-methyl) -phenyl-3,3-dimethylurea der formula

(II)

has a particularly broad and selective herbicidal activity in cereals.

Surprisingly, the effectiveness of the active ingredient combinations according to the invention is significantly higher than the sum of the Effects of the individual active ingredients. So there is an unpredictable real synergistic effect and not only an effect supplement. This synergistic effect shows up particularly strongly at certain concentration ratios.

The active ingredient combination according to the invention is superior to the active ingredients known from the prior art for combating weeds and grass weeds in cereals, because it is distinguished from these by a broader spectrum of activity and is also particularly well tolerated by crop plants. The _x fact that with the inventive

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Active ingredient combination also larger plants of Stellaria, media and. Matricaria chamomilla can be controlled much better than with the individual components known as herbicides. The active ingredient combination according to the invention thus represents a valuable enrichment of weed and weed control agents in cereals.

1- (2-Ben2Dthiazolyl) -1 ^ -dimethylurea of the formula (i) is known (see U.S. Patent 2,756,135).

1- (3-chloro-4-methyl) -phenyl-3,3-dimethylurea of the formula (II) is also known (cf. US patent specification 2,655,445).

The weight ratio of the individual components can be determined in the active ingredient combination according to the invention Areas fluctuate. In general, the active ingredient combination contains between 33 and 75, preferably between 46 and 64 percent by weight of 1- (2-benzothiazolyl) -1,3-dimethylurea. The weight ratio of 1 - * (2-benzthiazolyl) -1,3-dimethylurea to 1- (3-chloro-4-methyl) -phenyl-3,3-dimethylurea is therefore generally between 1: 2 and 3: 1, preferably between CJ87: 1 and 1.75: 1.

The active ingredient combination according to the invention shows a very good good effect against weeds and grass weeds without damaging the grain. It can therefore be used as a selective herbicide will.

Under weeds and grass weeds in the broadest sense are all To understand plants that are commonly found as contaminants in cereals. As weeds and grass weeds passing through destroyed the combination to be used according to the invention and are often found in cereals, for example: Dicotyledoneae such as chickweed (Stellaria media),

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Fume (Fumaria officinalis), corn poppy (Papaver rhoeas), Dead nettle (Lamium spec.) »Speedwell (Veronica spec.) Field lellerkraut (Thlaspi arvense), chamomile (Matricaria chamomilla) and Monocotyledoneae such as black foxtail (Alopecurus myosuroides), wind stalk (Apera spica-venti) and annual Bluegrass (Poa annua).

The active ingredient combination according to the invention can be converted into the usual formulations, such as solutions, emulsions, Suspensions, powders, pastes and granulates. These are prepared in a known manner, e.g. by mixing the Active ingredients with extenders, i.e. liquid solvents, liquefied gases under pressure and / or solids Carriers, optionally with the use of surface-active agents, that is to say emulsifiers and / or dispersants and / or foam-generating agents. In the case of using water as an extender, e.g. organic solvents can be used as auxiliary solvents. As a liquid solvent come in essentially Question: aromatics such as xylene, toluene, benzene or alkylnaphthalenes, chlorinated aromatics or chlorinated aliphatic Hydrocarbons such as chlorobenzenes, chloroethylene or methylene chloride, aliphatic hydrocarbons such as cyclohexane or paraffins, e.g. petroleum fractions, alcohols such as butanol or glycol and their ethers and esters, ketones such as Acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, strongly polar solvents such as dimethylformamide and dimethyl sulfoxide, and water; with liquefied gaseous Extenders or carriers are liquids which are meant, which at normal temperature and below Normal pressure are gaseous, e.g. aerosol propellants such as halogenated hydrocarbons, e.g. freon; as solid carriers: natural rock flour, such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite and Diatomaceous earth, and synthetic minerals, such as

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dispersed silica, aluminum oxia and silicates; as emulsifying and / or foam-producing agents: non-ionic and anionic emulsifiers, such as polyoxyethylene fatty acid esters, polyoxyethylene fatty alcohol ethers, e.g. alkylaryl polyglycol ethers, Alkyl sulfonates, alkyl sulfates, aryl sulfonates as well as protein hydrolysates; as dispersants: e.g. lignin, sulphite waste liquors and methyl cellulose.

The active ingredient combination according to the invention can in ■ the Formulations mixed with other known active ingredients are present. The formulations generally contain. between 0.1 and 95 percent by weight of active ingredient, preferably between 0.5 and 9.0 percent by weight.

The active ingredient combination can as such, in the form of their Formulations or the application forms prepared from them, such as ready-to-use solutions, emulsions, foams, suspensions, Powders, pastes and granules can be used. It is used in the usual way, e.g. by dusting, Spraying, splattering, pouring and scattering.

The application rates of the active ingredient combination can be varied within a certain range. You depend on the Composition of the combination of active ingredients and the weeds or grass weeds in the grain. In general the application rates are between 1.5 and 4 kg / ha, preferably between 2 and 3 kg / ha.

The use of the active ingredient combination according to the invention is preferably carried out after the emergence of the plants, but it can also be carried out before the emergence of the plants will.

The good herbicidal action of the active ingredient combination can be seen from the examples below. While the individual Active ingredients in the herbicidal effect on weaknesses

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show, the combination shows a wide range of weed effects, which goes beyond a simple summation of effects.

There is always a synergistic effect with herbicides before when the herbicidal effect of the combination of active ingredients is greater than that of the active ingredients applied individually.

The expected effect for a given combination of two herbicides (see COLBY, S.R., "Calculating synergistic and antagonistic responses of herbicide combinations ". Weeds 15, pp. 20-22, 1967) can be calculated as follows:

If X = % damage from herbicide A at ρ kg / ha application rate and Y =% damage from herbicide B at q kg / ha application rate and E = the expected damage from herbicides A + B at ρ + q kg / ha application rate,

then E = X + Y- ^X * ^Y

100

If the actual damage is greater than calculated, the effect of the combination is superadditive, i.e. it is a synergistic effect.

The tables in the following examples clearly show that the herbicidal activity found is the result of the invention Combination of active ingredients in weeds and grass weeds is greater than the calculated one, i.e. there is a real synergistic effect.

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example 1

Pre-emergence test / outdoors / autumn

The active ingredients listed in the table were .in more appropriate Formulation applied.

Shortly after sowing the test plants in the field, the individual plots were watered with such an amount of the active ingredient preparation as was necessary for uniform wetting of the soil surface. The active ingredient concentration in the preparation is irrelevant, only the amount of active ingredient per unit area is decisive.

After 4 months, the degree of damage to the test plants was determined and designated with the code numbers 0-5, which have the following meaning:

0 no effect

1 slight damage or growth delay

2 significant damage or stunted growth

3 serious damages and only poor development or only 50 i » accrued

4 plants partially destroyed after germination or only 25 '# emerged

5 plants completely dead or not accrued

Active ingredients, application rates and results are shown in the following table:

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Table 1
Pre-emergence test / outdoors / autumn

Active ingredient effort- Winter- Alopecurus Poa Veronica Fumaria Thlaspi

quantity of wheat myosuroides annua hederifolia officinalis arvense kg / ha

(known) (I)

2.1

3.5

4.5

CH, -

Vnh-c-n <

^X 3

(known) (II)

2.4

ω mixture of (I) u. (II) 2.25 ⁰⁰ Weight ratio

0.87: 1

(according to the invention)

-p »mixture of (l) u. (II) 2.2 * * x weight ratio
^r - * 1.75: 1

(according to the invention)

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4.5 0

3.5

3.5

4.8

Example 2

Post-emergence test / outdoors / autumn

The active ingredients listed in the table were applied in an appropriate formulation.

In the field, heavily weedy plots with test plants, which had a height of about 3-10 cm, were with a sprayed such an amount of the active ingredient preparation that a uniform wetting of the plants occurred. The decisive factor here is the application rate of the active ingredient per unit area, after The degree of damage to the plants was determined four months and denoted by the code numbers 0-5, which have the following meaning:

0 no effect

1 single light burn marks

2 distinct leaf damage

3 individual leaves and stem parts z. T. dead

4 plant partially destroyed

5 plant totally dead

Active ingredients, application rates and results are shown in the following table:

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Active ingredient

Table 2
Post-emergence test / outdoors / autumn

Effort- Winter- Alopecurus Veronica Matricaria quantity 'barley myosuroides hederifolia chamomilla kg / ha

Papaver
rhoeas

-N-C-NH-CH

(known) (I)

2.1

4.5

Cl

2.4 0

(known) (II)

J? Mixture of (i) and (II) 2.25 _tp weight ratio

co 0.87: 1

co (according to the invention)

^ Mixture of (I). u. (II) 2.2 - * weight ratio

* 1 1.75: 1

f ^ (according to the invention)

4.5

4.5

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Example 3

Post-emergence test / field / spring

The active ingredients listed in the table were applied in an appropriate formulation.

In the field, heavily weedy plots were tested with. plants that were about 3-10 cm high, with a sprayed such an amount of the active ingredient preparation that uniform wetting of the plants occurred. Crucial here is the application rate of the active ingredient per unit area. After four weeks, the degree of damage to the plants was determined and with the code numbers 0-5, which have the following meaning:

0 no effect

1 single light burn marks

2 distinct leaf damage

3 individual leaves and stem parts z. T. dead

4 plant partially destroyed

5 plant totally dead

Active ingredients, application rates and results come from the table below :.

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Table 3
Post-emergence test / field / spring

Active ingredient effort- Winter- Alopecurus Matricaria Lamium Fumaria

quantity of wheat myosuroides chamomilla purpureum officinalis kg / ha

-N-C-NH-CH, 2.1

(known) (I)

^0/8 y

NH-C-l /

\ CH ₃

(known) (II)

2.4

4.3

4.5

Mixture of (i) and (II) 2.25

Weight ratio S 0.87: 1

co (according to the invention) oo

■ p * mixture of (i) and (II) 2.2 "* - weight ratio ^ 1.75: 1
_- (according to the invention)

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4.5

4.5

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4.8

4.5

NJ U) O

Example 4

Post-emergence test / field. / Spring

The active ingredients listed in the table were applied in an appropriate formulation.

In the field, heavily weedy plots were planted with test plants, which had a height of 5-20 cm, sprayed with such an amount of the active ingredient preparation that one uniform wetting of the plants occurred. The decisive factor here is the amount of active ingredient applied per unit area. The degree of damage to the plants was determined after four weeks and denoted by the code numbers 0-5, which have the following meaning:

0 no effect

1 single light burn marks

2 distinct leaf damage

3 individual leaves and stem parts z. T. dead

4 Plant partially destroyed. 5. Plant totally dead

Active ingredients, application rates and results come from the table below :.

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Table 4
Post-emergence test / Preiland / Spring

Active ingredient effort- Winter- Alopecurus Apera Stellaria Fumaria Veronica

amount of barley myosuroides spica media officina- hederikg / ha venti lis folia

NH-CH,

ca ο ca

{known) (I)

, CH, -NH-C-N ^

(known) (II)

2.1

2.4

1.5

4.5 4

.4.5

4.5

0.5

Mixture of (i) and (II) weight ratio 0.87: 1

(according to the invention) Mixture of (i) and (II) weight ratio 1.75: 1

(according to the invention)

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2.25

2.2

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4.8

4.8

Claims (5)

Claims 1) Means for selective weed and weed control in Grain, characterized by a content of an active ingredient combination, consisting of (1) 1- (2-Benzothiazolyl) -1,3-dimethyl urea of the formula -N-C-NH-CH, (I) and (2) 1- (3-chloro-4-methyl) -phenyl-3,3-dimethylurea the formula H _x C- / Vnh-cn ^ - (H) Cl 2) means according to claim 1, characterized in that the weight ratio of the 1 - (2-benzothiazolyl) -1 »3- • dimethylurea to the 1- (3-chloro-4-methyl) -phenyl-3,3 * -dimethylurea is between 1 to 2 and 3 to 1. 3) A method for combating weeds and grass weeds in cereals, characterized in that there is a combination of active ingredients according to claims 1 or 2 can act on the weeds or grass weeds or their habitat. 4) Process for the production of agents for selective weed and weed control in cereals, thereby Le A 14 408 - 15 - 309884 / U13 indicates that an active ingredient combination according to Claim 1 or 2 mixed with extenders and / or surface-active agents. 5) Use of active ingredient combinations according to claims 1 and 2 for selective weed and weed control in Grain. Le A 14 408 - 16 - 309884/1413