DE1034912B - Means for destroying weeds - Google Patents

Description

The use of aryl carbamic acid esters as herbicides is known. In particular, the isopropyl N-phenylcarbamate is found and the isopropyl N- (m-chlorophenyl) carbamate use against monocotyledons Plants.

It has now been found that aryl carbamic acid ester of. formula

.CH ₉

> _NH-C-O-CH;

or

■ \ _nh — c —o — ch:

C = CH

CH,

CH = CH, means for destroying weeds

Applicant: ■

Badische Anilin- & Soda-Fabrik Aktiengesellschaft, Ludwigshafen / Rhein

Dr. Hermann Windel, Ludwigshafen / Rhine,

Dr. Adolf Fischer, Mutterstadt (Palatinate),

and Dr. Herbert Stummeyer, Mannheim,

have been named as inventors

especially if they are substituted by chlorine in the m-position, deh isopropyl esters previously used in practice are superior, since the amounts required are lower. For example, only 2.7 kg / ha of m-chlorocarbamic acid butenol ester are required to control weed plants in strawberries, in contrast to 4 kg / ha for isopropyl N-im-chlorophenyl / carbamate. In addition, in some cases, greater protection of the crop is achieved. [It has also been found that mixtures of these carbamic acid esters with hydantoin derivatives of the following formula, in which Z denotes hydrogen, alkyl or a metal, ammonium or substituted ammonium ion, R denotes a lower aliphatic radical, preferably methyl, and η denotes the numbers 1 to 3 :

X =

chlorine
n - l

, -NH-C-N.

^X CH ₂ -COOZ

or

X =

__ N C = O

Chlorine O = C

η - 1

N ₁ - R,

C.
H,

_r show effects which can not be achieved with the components alone f. The use of these hydantoin derivatives as such for the purpose of weed control is the subject of the earlier patents 1,018,261 and 1,023,628. The amounts required to achieve the desired effect are lower than when using the individual components due to a synergistic effect. In addition, the mixtures are particularly suitable for controlling weeds which are otherwise difficult to destroy, e.g. B. French cabbage and ragwort. Examples of hydantoin derivatives are ^ -Methyl- (5-phenylhydantoic acid or l-methyl-3-phenylhydantoin, β -methyl-δ- (4-chlorophenyl) -hydanioiric acid and l-methyl-3- ^ 4-chlorophenyl ) -hydantoin, / 3-methyl- δ - (3,4 - dichlorophenyl) - hydantoic acid or; 1 -Methyl-3- (3,4-dichlorophenyl) hydantoin and among the salts; Of these acids, the calcium and sodium salts are particularly well suited. ,, ..; The carbamic acid esters and the mixtures "with other herbicidally active substances, for example the hydantoin derivatives, can be used in organic solution: as, emulsion or suspension and extended with inert substances or fertilizers.

The carbamic acid esters mentioned can be prepared by reacting the isocyanates or the carbamic acid chlorides with butyn-1-ol-3 or buten-1-ol-3 or the chloroformic acid esters of these alcohols with the corresponding Amines. The hydantoin derivatives are preferred by reacting the isocyanates with the salt of a secondary aliphatic aminocarboxylic acid. This gives the salts of hydantoin acid, from which the free acid can be obtained by careful acidification. When standing in acidic solution closes the ring to hydantoin.

example 1

Wild oat seeds (Avena fatua), mustard (Sinapis alba) and burdock (Galium aparine) are placed in the top layer of compost. To this Soil, carbamic acid butynol ester or carbamic acid butenol ester is used as a dispersion in quantities of 2.5 kg / ha

809 578/451

evenly sprayed. Mustard and burdock plants emerge normally. The growth of the wild oatmeal was strongly inhibited by the treatment. ^v ■ ■

Example 2

In a seed bowl filled with soil, 25:30 cm, Carrot, onion, pea, beet, mustard and airport seeds are sown in transverse rows. In the surface this so prepared soil becomes m-chlorocarbamic acid butenol ester Evenly applied in an amount of 3 kg / ha in 1000 l of water. After about 4 to Normal growth can only be observed in carrots and onions for 5 weeks. Peas and beet plants are somewhat inhibited in their growth. Mustard and mustard are almost completely dead after this time Airport seedlings.

Example 3

Wild oats and rye (as monocotyledon test plants), field mustard, oil rocket, oil radish are grown in open-air plots and beets (as dicotyledon test plants) sown. On the same day 3 kg / ha of carbamic acid butynol ester (BPC) and 4 kg / ha isopropyl carbamate (IPC) as a dispersion in 1000 l of water on each Plots sprayed. In the following table, using the rating scheme given below, the herbicidal effect of the two substances reproduced 8 weeks after treatment:

Monocotyledon test plants Substance ι Wild oats I Rye

Dicotyledon test plants

oil radish

mustard

Oil rocket

turnip

IPC

4 kg / ha

BPC

3 kg / ha

4 to 5
3 to 95%)

5 (95%)

5 (95%)

5 (100%)

1
(10 to 20%)·

0 (0%)

0 (0%)

0 (0%)

1
(10 to 20%)

0 (0%)

(30%)

1
(10 to 20%)

Example 4

In a new plantation of strawberries, 2.7 kg / ha m-chlorocarbamic acid butenol ester (CEPC) and 4 kg / ha TO-chlorocarbamic acid isopropyl ester (CIPC) are sprayed onto the field in the early autumn. The plot size is 3.75 m ² , the amount of spray liquid is 101 / ar. The evaluation 4 weeks later is recorded in the following table:

substance

Strawberries

Stinging nettle

Weed plants
Chickweed | Chicken millet j French herb j

Ragwort

CIPC

4 kg / ha

CEPC
2.7 kg / ha

0 to 1
(0 to 10%)

0 (0%)

4 to 5 (90 to 100%)

5 (100%)

5
(100%)

(100%)

4 to 5 1 to 2 | 1 to 2

(90 to 100%) (10 to 30%) j (10 to 30%)

5 I 2 2

(95 to 100%): (30%) j (30%)

Rating scheme for the examples. 3 and 4

Killing effect

0 = without damage 0%

1 = single leaves with very small

Damage 10 to 20%

2 = little damage or inhibition of the

most plants 30 to 50%

3 = severe damage, but not leaves

dying, whole plants damaged 50 to 70%

4 = most of the leaves and also

individual plants dead 70 to 90%

5 = plants completely destroyed 90 to 100%

Example 5

3 kg / ha of m-chlorocarbamic acid butenol ester + 4 kg / ha 1-methyl-3- (3,4-dichlorophenyl) hydantoin are mixed in 1000 liters of water with the aid of a dispersing agent and applied to the following plants: Sinapis alba, Stellaria media, Avena fatua, Polygonum persicaria, Galinsoga parviflora, Senecio vulgaris and Poa annua. After 8 to 10 days, light appearances on the leaf tips Wilting phenomena and inhibitions to grow. The plants are stunted after a further 28 days.

Example 6

In light sandy soil, carrot and onion seeds are sown ^{on several 2 m 2 plots.} On the same day / J-methyl-p-chlorophenylhydantoic acid (I) in an amount of 1.5 kg / ha, m-chlorocarbanilic acid-1,3-butynol ester (II) in an amount of 4.5 kg / ha and I + II combined in an amount of 1 kg / ha of 1 + 2 kg / ha of II, whereby the amount of water for each treatment method is 10001, sprayed on the ground. After 4 weeks, the crop plants emerged without any disturbance. To illustrate the herbicidal effect of these two substances, individually and in combination, the number of weeds in the following table is used:

50 control 1.5 kg / ha
I. • 4 kg / ha
II lkgl
+ 2 kg
Il / ha Report
Spergula
wild radish
Flea Knotweed ...
Chickweed
French herb ..
_6o chamomile
Annual grass
Ragwort
Dead nettle
Shepherd's purse ...
₆₅ vetch 263
5
6th
11
176
51
45
27
11
6th
12th
8th 28
2
3
1
16
4th
9
7th
13th
1
2
0 22nd
1
2
0
0
28
18th
0
14th
0
7th
1 11
0
0
0
0
0
2
0
1
0
2
0 Sum of Un
herbaceous plants. . 621 86 93 16

The individual numbers indicate mean values from four tests carried out at different times.

Example 7

In two bowls filled with a light sandy soil, seeds are placed in the top layer of the soil Sinapis alba, Panicum sanguinale and Galium aparine 'sown. One shell is filled with an aqueous emulsion of m-chlorocarbanilic acid butynol ester. (I) and the another shell with an aqueous emulsion of propargyl m-chlorocarbanilate (II) treated in such an amount that corresponds to 1 kg of the active ingredient per hectare of treatment area. Show 7 weeks after treatment • the following damage, expressed as a percentage:

Sinapis alba Panicum
sanguine Galium
aparine I. 40
10 70
15th 50
10 II

It follows that the substance I to be used according to the invention is significantly more effective than Substance II, which was previously proposed as a herbicide.

Claims (2)

Patent claims: 1. Weedkillers characterized by a content of aryl carbamic acid esters of the formula , CH, / \ —NH-C —O —CH CH = CH ₂ and their derivatives, which are formed by substitution in the m-position by chlorine. 2. Weed repellants, characterized by a content of aryl carbamic acid esters according to claim 1 in a mixture with hydantoins of the following formula in which Z is hydrogen, alkyl or a metal, ammonium or substituted ammonium ion, R is a lower aliphatic radical, preferably methyl, and η the Numbers 1 to 3 mean: NH-C --Ν! N- ^ CH ₂ -COOZ ; —NH-C —O —CH C = CH Chlorine O = C «-1 V H, -C = O ,NO © 809 578/451 7.