DE1221840B - Means for combating aquatic weeds - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

Int. Cl .:

AOIn

GERMAN

PATENT OFFICE

EDITORIAL

German class: 451-9 / 20

Number:
File number:
Registration date:
Display day:

1221840
F 40812IV a / 451
September 21, 1963
July 28, 1966

It has been found that the carbamic acid esters of the formula

Means for controlling aquatic weeds

: = N —Ο —C —NH-R (I)

Cl

in which R stands for a phenyl radical optionally substituted in the o-position by chlorine, very good are suitable for controlling water weeds.

The carbamic acid esters of the general formula mentioned above are prepared in accordance with known ones Methods, e.g. B. by reacting the corresponding aromatic hydroxamic acid chlorides with isocyanates or with carbamic acid chlorides and subsequent reaction of the chloroforms obtained in this way or biscarbonic acid esters with primary or secondary amines.

The hydroxamic acid chlorides required as starting materials can be obtained in a manner known per se the corresponding aldehydes and hydroxylamine by subsequent chlorination of the formed Hydroxamic acids are obtained.

It is known that Diquat (l, l'-ethylene-2,2'-bipyridylium bromide) to combat submerged Aquatic plants can be used. The effect of the compounds according to the invention against im Water-flooding weeds such as Elodea densa and Myriophyllum brasiliensis corresponds to that of Diquat, while the effect against rooting weeds such as Ceratophyllum demersum, Najas guadalupensis and Potamogeton spec, the effect of Diquat is superior.

It has also become known that certain carbamide oximes are used as herbicides can (see German Auslegeschrift 1 024 746). The carbamic acid esters to be used according to the invention however, have a higher herbicidal potency against aquatic weeds than the most herbicidally effective known carbamide oxime.

It is also known that the carbamic acid esters to be used according to the invention as water herbicides have fungicidal properties and are therefore used to combat fungal diseases on plants can be (Belgian patent specification 621 961). However, these fungicides are not used in the Water used to fight fungal diseases on aquatic plants.

Applicant:

Paint factories Bayer Aktiengesellschaft,

Leverkusen

Named as inventor:
Dr. Ludwig Eue, Cologne-Stammheim;
Dr. Helmuth Hack, Cologne-Buchheim;
Dr. Rudolf Heiss, Cologne-Stammheim;
Dr. Gerhard Burm.eister, Cologne-Mülheim

example 1

The following types of plants were planted in 200-1 containers: Elodea densa, Myriophyllum brasiliensis, Ceratophyllum demersum, Potamogeton spec, and Najas guadalupensis. The containers were then left for weeks to give the plants a chance give to get used to the surroundings. The connections were tested:

2 Br- (Diquat) I

N-O-C-NH- ^

Il : = N - o - c - NH

Cl

which were sprayed evenly onto the container as aqueous emulsions or solutions. the Plants were rated for degrees of damage after 2 and 5 weeks. The final evaluation is in compiled in the table. The values are mean values from two repetitions.

609 607/377

I 2.5 ppm
5.0 ppm

II 2.5 ppm
5.0 ppm

III 2.5 ppm
5.0 ppm
control

Elodea

4.5
4.9

4.6
5.0

3.6
5.0
0.3

Myrioph.

5.0
5.0

5.0
5.0

4.8

5.0

'0.5

Ceratoph.

4.3 4.9

3.5 5.0

3.5 4.9 0.0

Najas

2.0 3.4

1.5 5.0

2.5 5.0 0.0

Potamogeton

0 = no damage,

1 = death of individual leaves,

2 = one third of the plant dead,

1.0 2.0

2.5 4.9

3.8 5.0 0.5

3 = half of the plant dead,

4 = plants dying, but still leafy green,
4,5 = only single green parts,

5 = plant totally dead.

Example 2

In a trial, three plant species, Elodea densa, Myriophyllum brasiliensis and Vallisneria were used spiralis, exposed to different concentrations of the active substances to be tested for only hours. After this exposure, the plants were transferred to normal tap water and after The degree of damage is rated for 3 weeks. The results are compiled in the table below.

Active ingredient

Elodea
hours

Myriophyllum
hours

Vallisneria
hours

- η - η - χτ = r - ν χ

5 5 5 4.2

5
5

4.5

4.5
4.5
4th

5
5
4.8

4.5
4.5
4.8

From this experiment it can be seen that the exposure over a certain limited period of time enough to cause the plants to die, which is of particular importance in the case of destruction of aquatic plants in flowing water is ·.

Example 3 Aquatic Plant Test / Still Water

Solvent: 10 parts by weight of acetone Emulsifier: 5 parts by weight of alkyl aryl poly

glycol ether

To produce an appropriate preparation of active ingredient, 1 part by weight of active ingredient is mixed with the specified amount of solvent, add the specified amount of emulsifier and dilute the Then concentrate with water to the desired concentration.

You plant aquatic plants in a large container, the bottom of which is covered with soil and the one with it Tap water is filled. The plants remain

in it untreated for about 3 weeks to get used to it. The active compound preparation is then sprayed on the water surface and stir. The concentration of the active ingredient in the plays a role here Preparation does not matter, the only decisive factor is the amount of active ingredient per unit volume of water in the container.

After a certain residence time in the treated water, the degree of damage to the plants is reduced Use of the following key figures rated:

0 = no damage,

1 = death of individual leaves,

2 = one third of the plant dead,

3 = half of the plant dead,

4 = plants dying, but still green,
4,5 = only single green parts,

5 = plant totally dead.

Active ingredients, active ingredient concentrations, aquatic plants, residence times and degrees of damage go from the table below.

Aquatic plant test / still water

Active ingredients

Active ingredient concentration
in ppm

Degrees of damage according to the following
Dwell times

Elodea Myriophyllum

Vallisneria

(CHs) ₂ C = NOC-NH

(known, see German Auslegeschrft 1 024 746)

1.25

0 0 0

4th
4th
1

3 0 0

continuation

Active ingredients O Cl Active ingredient
concentration
in ppm Damaging
Elodea degree of efficiency according to c
Dwell time
Myriophyllum len following
η
Vallisneria Ν — 0 — C — N O 5
2.5
1.25 5
5
4.5 5
5
5 4.5
4.5
4.5 Ν — 0 — C — N 5
2.5
1.25 5
4.5
2 Ul ul ul 5
4.5
2 > - <
C. : i C. : i

Claims (1)

Claim: Agent for controlling aquatic plants, characterized by a content of Carbamic acid esters of the formula in which R stands for a phenyl radical which is optionally substituted in the o-position by chlorine. : = N —O —C —NH-R (I) Cl Considered publications: German Auslegeschrift No. 1024 746; Belgian patent specification No. 621 961.