DE1151975B - Selective means of destroying undesirable plant species - Google Patents

Description

Derivatives of trichloroacetic acid are known agents for combating weeds (see US Pat 2,393,086). Sodium trichloroacetate is widely used in practice where it is primarily the destruction of monocotyledon weeds is important. Furthermore, derivatives of the Chlorais as a weed control agent, again with a preferential effect on Gramineae, became known (German patent specification 1 003 497).

A selective means of destroying undesirable plant species has now been found, in particular of grass species in agricultural and horticultural crops, which is characterized by a simultaneous content of a salt of trichloroacetic acid, e.g. B. an alkali, alkaline earth, Ammonium or amine salt, and N- (1-hydroxy-2,2,2-trichloroethyl) monoehloroacetamide, preferably in the ratio of 65: 35% to 50: 50%.

N- (I-hydroxy-2,2,2-trichloroethyl) - monochloroacetamide the formula

ClH ₂ C - CO - NH- CH (OH) - CCl ₃ ,

hereinafter referred to as chloroacetic acid trichloroethylolamide, can be obtained by reacting chloral hydrate with Chloracetamide in the presence of sulfuric acid as a catalyst according to the German method Patent 949,946 can be produced. The compound is very sparingly soluble in water. To use chloroacetic acid trichloroethylolamide is incorporated into the soil before sowing.

The mechanical control of weeds in Ölfrucht- 'legumes and sugar beet crops is known, the more difficult the greater the proportion of graminaceous weeds among the will. In z. B. areas contaminated with wild oats, beet and pea cultivation can become uneconomical and therefore come to a standstill. To remedy this deficiency, salts of trichloroacetic acid and chloroacetic acid trichloroethylolamide were now examined for their suitability for combating weeds in sugar beet and peas. It was found that the mixture of the two products according to the invention surprisingly produces a synergistic effect. Not only is the known effect of the individual components against monocotyledon weeds increased and the addition effect of the two components far exceeded, but damage to the crops is also avoided at the same time. The increase in effectiveness against grasses with an increase in the selectivity of the agent was unexpected.

It is true that US Pat. No. 2,589,162 discloses a synergistic mixture of salts of the tri-selective agents for destruction
undesirable plant species

Applicant:

Farbwerke Hoechst Aktiengesellschaft

formerly Master Lucius & Brüning,

Frankfurt / M.

Josef Kaupp, Dr. Erich Hambsch,

Gersthofen via Augsburg,
Dr. Heribert Hahne and Dr. Ernst Weite,

Hofheim (Taunus),
have been named as inventors

chloroacetic acid with chlorates described and in the French patent specification 1,155,006 claims that 3-amino-1,2,4-triazole produces a synergistic effect in combination with common herbicides emerged. However, such a general statement is not possible. In the same Belgian patent 548 857 are salts of trichloroacetic acid together with salts of monochloroacetic acid and optionally used with trifluoro-nitrophenols to kill potato tops. From a synergistic effect there is no question of it. From the cited literature it could not be concluded that salts trichloroacetic acid with N- (l-hydroxy-2,2,2-trichloroethyl) monochloroacetamide has a potentiated effect unfold. In the three publications mentioned it is still, in contrast on the subject at hand, not selectively acting weed killers. You can therefore cannot be used in agricultural and horticultural crops.

The mode of action of preparations that are used in the pre-emergence process is so far from Depending on the weather, as preparations with low water solubility to fully develop their effect Relatively high amounts of precipitation require, preparations with high water solubility, however, quickly are washed out and therefore the optimum of their effect even with lower amounts of precipitation

309 648/257

reach. The combination according to the invention of a readily water-soluble agent (e.g. sodium trichloroacetate) with a practically water-insoluble compound (chloroacetic acid trichloroethylolamide) therefore a means with less dependence on the weather. This means in practice a higher chance of success treatment and represents a further technical advance.

The mixtures according to the invention can be blended with inert material, e.g. B. talc or Sand, can be used in the form of grit, but better in combination with a dispersant in the form of wettable powders according to "Means 3" of the following exemplary embodiment. The application is carried out in advance, 3 to 14 days before sowing.

Example 1 Selective weed control in sugar beets

Weeds

Medium 1 30th 10 10 20th kg / ha kg / ha kg / ha kg / ha 3 128 120 16 73 110 143 120 12th 35 46 22nd 16 21 31 18th 10 9 20th 14th 13th 35 38 16 3 0 1 2

Medium 2

20th
kg / ha

Medium 3 30th 30th 20th kg / ha kg / ha kg / ha 2 38 7th 0 4th 23 3 3 13th 0 4th 4th 4th 4th 5 0 2 13th 0 3 0

Untreated

Wild oats (Avena fatua),

Field mustard (Sinapis arvensis),

Melde (Chenopodium album)

Chickweed (Stellaria media)

Burdock weed (Galium aparine).,

Knotweed

(Polygonum convolvulus)

Plant damage

Medium 1

Sodium trichloroacetate dissolved in 8001 water per hectare.

Medium 2

With dispersant stearic acid methyl tauride 3 ⁰ I ₀ , finely divided silica 4% sodium sulfate, sicc, 8% added wettable powder which contains 85% chloroacetic acid trichloroethylolamide, dispersed in 8001 water per hectare.

Medium 3

With dispersants stearic acid methyltauride 2 ° / _0, finely dispersed silica 4%, sodium sulfate (sicc), 9% offset mixture of 40% sodium trichloroacetate and 45% chloroacetic acid trichloräthylolamid, in 8001 water per hectare.

Day of treatment:

12 days before sowing
(Variety Kleinwanzlebener).

86 38 7 2 312

16! 4 23 0 168

8 3 13 3 47

6 4 4 0 36

5 4 5 4 21

6 2 13 0 46

Rating:

8 weeks after sowing.

The experiments were carried out with 4 repetitions. Plot size: 30 m ^a .

The rows of numbers behind the weed names mean the number of weeds in question per square meter average of all repetitions.

The plant damage was assessed according to the following scheme:

of sugar beet

45

0 = no damage.

1 = slight curling of the cotyledons.

2 = slight curling of the cotyledons and

first pair of leaves.

3 = growth retardation after 2 to 4 weeks

is caught up again.

4 = permanent growth inhibition or severe

Damage.

5 = total annihilation.

Example 2 Selective weed control in peas

Weeds 5
kg / ha Medium 1
15th
kg / ha 25th
kg / ha 5
kg / ha Medium 2
15th
kg / ha 25th
kg / ha 5
kg / ha Medium 3
15th
kg / ha 25th
kg / ha Inconvenient
acts Wild oats (Avena fatua) ....
Field mustard (Sinapis arvensis)
Melde (Chenopodium album)
Ragwort (Senecio vulgaris)
Dead nettle 82
41
3
20th
14th
1 24
22nd
2
18th
18th 6th
18th
2
18th
5
4th 135
19th
1
19th
11
0 48
26th
3
4th
11
3 17th
12th
1
12th
10
3 55
37
1
15th
10
0 3
19th
1
6th
5
0 3
15th
1
3
1
1 222
36
4th
21
12th
0 (Lamium purpureum)
Plant damage

Treatment 10 days before sowing

Assessment 7 weeks after sowing

Loess loam soil

Number of plates

Parcel size 10 m ² with four repetitions

The table values were explained in Example 1, but average 1 and 3 are sodium trichloroacetate replaced by ammonium trichloroacetate.

Example 3
Selective weed control in oil radish

Weeds 5
kg / ha Medium 1
15th
kg / ha 25th
kg / ha 5
kg / ha Medium 2
15th
kg / ha 25th
kg / ha 5
kg / ha Medium 3
15th
kg / ha 25th
kg / ha Inconvenient
acts Black foxtail 46 7th 7th 61 7th 14th 26th 2 4th 62 (Alopecurus myosuroides)
Blade of wind 14th
16
5 5
11
2 5
10
1 19th
10
2 11
7th 3
2
1 5
11
9 1
5
1 1
4th
1 18th
14th
3 (Agrostis spica venti)
Chickweed (Stellaria media)
Dead nettle 1
8th
0 O O OJ 1
4th
3 0
5
0 1
5
0 0
0
3 1
6th
O O
O
O O
4th
O 3
9
O (Lamium purpureum)
Ragwort (Senecio vulgaris)
Melde (Chenopodium album)
Plant damage

Treatment 3 days before sowing

Assessment 10 weeks after sowing

Soil Loamy sand

Number of plates

Plot size 10m ² with three repetitions

The table values were explained in Example 1, but average 1 and 3 are sodium trichloroacetate has been replaced by calcium trichloroacetate.

Claims (2)

PATENT CLAIMS: 1. Selective means for the destruction of undesirable plant species, especially grass species in agricultural and horticultural crops, characterized by a simultaneous content of a salt of trichloroacetic acid, z. B. an alkali, alkaline earth, ammonium or amine salt, and N- (I -hydroxy ^^^ - trichloroethylJ-monochloroacetamide, preferably in a ratio of 65: 35% to 50: 50%. 2. Means according to claim 1, characterized in that it is the mixture of active substances in a mixture with solid carriers as a scattering agent or in combination with dispersants as a wettable powder contains. Considered publications:
German patent specifications No. 949 946, 1 003 497, 1,010,314; French Patent Specification No. 1,062,826, 1155006; Belgian Patent No. 548,857;
U.S. Patents Nos. 2,393,086, 2,589,162, 2,622,974. © 309 648/257 7.63