DE1792733C3 - Selective herbicides - Google Patents

Description

NO,

(Bp. 0.02 mm / 138 to 141 ° C)

The present invention relates to MitIeJ zur Selek tiven control of undesired plant growth, containing a compound of the general formula

(D

wherein R is 4-chlorophenyl, 2,4-dichlorophenyl, 2,4,6-trichlorophenyl, 4-chloro-3,5-dimethylphenyl, Means 4-methylphenyl- or 4-methoxyphenyhest, and optionally at least one of the following additives: diluents, solvents, Wetting agents, emulsifiers, adhesives, fertilizers or other pest control agents with IeI.

Examples of the compounds of general formula I include:

(M.p. 38 to 40 C)
b) Cl- / ~ \ -O- <f y- CF ₃

NO ₂
(M.p. 47.5 C)

Cl

c) Cl

CF ₃

NO ₂

(M.p. 92 to 94 C)

d) CH ₃ -OZ ^- VO - / "~ VcF,

NO ₂

(Kn. 2.5 mm / 175 to 18O ^C C)

The agents according to the invention have a pronounced pre-emergence and post-emergence effect especially against different types of gramineae and are z. B. excellent for weed control in cereal crops and in crops of dicotyledons.

The new agents can be emulsified, dispersed or in dissolved form or as dust withUM. where they are also used together with other herbicides, Fertilizers or pesticides can be applied. Come to the production of directly sprayable solutions z. B. Mineral fractions from high to medium boiling range, such as diesel oil or kerosene, also coal tar oils, and oils of vegetable or animal origin as well as medium and higher hydrocarbons, such as alkylated naphthalene, tetrahydronaphthalene, into consideration, optionally using xylene or toluene mixtures, or ketones or alcohols such as cyclohexanone, cyclohexanol, and also chlorinated ones Hydrocarbons such as tetrachloroethane, trichlorobenzene, trichlorotoluene, and chloroxylenol.

Aqueous application forms are made from emulsion concentrates, Pastes or wettable powders are prepared by adding water. As an emulsifying or dispersants are non-ionic products, z. B. Condensation Products of aliphatic alcohols, amines or carboxylic acids with a long-chain hydrocarbon off rest of about 10 to 30 carbon atoms with ethylene oxide, such as the condensation product of octadecyl alcohol and 25 to 30 moles of ethylene oxide or that of technical oleylamine and 15 moles of ethylene oxide or that of dodecyl mercaptan and 12 moles of ethylene oxide. Among the anionic emulsifiers, which can be used, should be mentioned the sodium salt of dodecyl alcohol sulfuric acid ester, the sodium salt of dodecylbenzenesulfonic acid, the potassium or triethanolamine salt oleic acid or abietic acid or mixtures of these acids, or the sodium salt of one Petroleum sulfonic acid. Quaternary ammonium compounds are used as cationic dispersants, such as cetylpyridinium bromide or Dioxyäthylbenzyldodecylammoniumchlorid into consideration.

For the production of grit or dust, z. B. granules can be used as solid carriers Talc, kaolin, bentonite, calcium carbonate, calcium phosphate, but also coal, cork flour, wood flour and other materials can be used. The various application forms can be used in Usually with an addition of substances, which

the distribution, the adhesive strength, the rain resistance or improve penetration, be provided; as such substances are mentioned: fatty acids. Resins, glue, casein or e.g. B. also alginates.

Under weeds or unwanted vegetation, which are combated with the new agents, are also undesirable z. B. at an earlier point in time on the area to be treated to understand cultivated crops.

The compounds of general formula 1 can be prepared by methods known per se be e.g. B. by reacting a phenol substituted according to the meanings of R with a compound of the general formula

Shark

CF ₃

NO,

20th

wherein Hai represents a halogen atom, such as e.g. B. a chlorine atom, stands, with elimination of hydrogen halide.

The invention is described in more detail in the following examples. The temperatures are in degrees Celsius specified. Parts mean parts by weight, percentages mean percentages by weight.

B e i s ρ i e 1 1

Wettable powders are produced which each contain 20% of one of the compounds a) to 0 according to Table 1 contain and 10% of an emulsifier, consisting of a mixture of an alkylphenol polyglycol ether z. B. the polyglycol ether of p-iso-octylphenol and a calcium or magnesium salt of an alkyl aromatic sulfonic acid z. B. the Monolaurylbenzol-mono-sulfonsäurc.

The wettable powders are mixed with water in any desired manner, resulting in stable dispersions receives.

Example 2

There were selective action of the compounds a), b), c) and d) of Table 1 according to the present application against weeds in the presence of wheat and barley plants compared to the known Herbicide 4,6-DinitΓo-2-sec-butylphenol.

In the greenhouse, the following types of seeds are sown in flower pots filled with soil: Alopecurus, Poa, Dactylis, Lolium, Cynosurus, Avena fatua as well as Triticum and Hordeum.

Treatment is carried out 2 days after sowing the above types of seeds (before emergence). The individual pots are mixed with a spray mixture prepared according to Example 1, containing 0.1% of an active ingredient according to Table 1 corresponding to an application rate of 6 kg of active ingredient per hectare. The evaluation was carried out 20 days after the treatment.

The evaluation was carried out according to a scheme from 0 to 10; 0 means: no damage to the plant: 10 means: plants completely dead; a value above 5 means: the plant is so badly damaged, that she can no longer recover.

The following table shows the result.

Test plant connection nemäE b) c) d) 4,6-di- 2 3 2 nitro- Table I of the application 2 sec. 2 2 1 butyl phenol Triticum a) 7th 6th 7th (Wheat) 2 6th 7th 8th Hordeum 7th 7th 7th 4th (Barley) 2 8th 7th 7th Alopecurus 7th 6th 9 2 Poa 7th 7th 8th 7th 3 Dactylis 8th 2 Lolium 6th 3 Cynosurus 6th 3 Avena falua 7th 3 (Wild oats) 8th

25th

30th

35

40

45

₅₀ From the above result it can be seen that only in the case of the agents according to the invention a sufficient control of the weeds is possible while protecting the useful plants wheat and barley, while the action of the known herbicide 4,6-dinitro-2-sec-butylphenol against the weeds in question is insufficient.

Example 3

The selective herbicidal action of the compounds c) and d) was compared with the present application Weeds in the presence of rice, maize and soy with compound A, which is previously known as a herbicide: 2.3 - Dichloroallyl - diisopropyl - thiocarbamate (Avadex®; British patent specification 8 82111) compared.

The test was carried out by the pre-emergence method in the manner described in Example 2. There were aqueous spray liquors which contain the emulsifiers described in Example 1 and in each case 0.1% of the active ingredient in question. The amount of active ingredient that was injected corresponded to one Application rate of 3 kg per hectare or 2 kg per hectare for the numbers marked with *.

The evaluation was carried out according to the following scheme:

1 no damage to plants
9 plants completely dead
5-8 Plant so badly damaged that it cannot recover.

The result is summarized in the following table.

₅₅ test plant connection
according to the invention

Avadex®

c)

d)

60

65

Avena 3 6th 9 Alopecurus 7th 3 9 Poa 9 9 1 Digitaria 9 9 9 Panicuni 9 6th 9 Linum 8th 7th 5 Brassicia 9 4th 3 Amaranthus 9 3

continuation connection
according to the invention
et d) 1
1
I. Asadcx® Test plant 1
1
1 9 *
5 *
8th* rice
soy
Corn

It turns out that only in the case of the agents according to the invention is adequate control of the Weeds while protecting the useful plants is possible.

Example 4

During a screening test in the greenhouse, the herbicidal activity of the compounds

O V-Cl (A)

NO,

(4 - chloro - 2 - nitrophenyl - 4 '- chlorophenyl ether, known from German patent 9 63 111) and

(b)

(2 - nitro - 4 - trifluoromethylphenyl -4 '- chlorophenyl

ether, connection b of the present application).

The compounds (20%) were with Bolus alba (70%) and the emulsifier specified in Example 1 (10%) processed into a wettable powder, which is diluted with water and ic the concentrations given below was used.

In the greenhouse, clay pots 15 cm in diameter were then filled with soil and sown with the following types of plants:

Cultivated plants: maize, seed oats;
Monocotyledons "weeds": millet.

Ragweed;
Dicolyledons "weeds": white mustard.

Alfalfa, garden cress and marigold.

The pre-emergence treatment took place 2 days, the post-emergence treatment 12 days after sowing, after the plants had emerged and 2 to 3 real leaves had set. The results were obtained 3 weeks after the treatment. During this time the pots were in the greenhouse under optimal conditions of heat, light and humidification.

The condition of the plants was then assessed as follows:

0 = no effect, plant develops normally, like untreated control plant,

10 = plant dead,
1-9 = intermediate stages of damage.

The results are summarized in the following table.

connection

Way of treatment

Pre-emergence method Post-emergence method Pre-emergence method Post-emergence method

Application rate 10 in kg / ha 1 50 10 2 3 50 10 2 50 10 1 50 2 7th 5 4th plant 5 10 8th 5 10 3 2 0 3 2 10 Zea mais 7th 10 10 10 8th 10 9 6th I. 6th 5 10 Avena sativa 10 10 0 10 10 2 10 10 10 10 10 1 Setaria italica 10 10 5 10 10 8th 10 10 9 10 10 7th Dactylis glomerata 10 1 10 10 2 5 1 0 0 8th 3 1 Sinapis alba 9 9 1 10 8th 3 7th 7th 6th 8th 7th 0 Medicago sativa 10 10 10 6th 3 1 0 5 3 Lepidium sativum 10 4th 10 6th 0 0 0 2 1 Calendula chrysantha 9

In this experiment, both compounds show good herbicidal properties. Both protect the maize crop in the pre- and post-emergence method at practically usable application rates of less than 5 kg / ha. Compound (b), in which a chlorine atom has been replaced by the CF ₃ group compared to (A), appears to be the stronger herbicide in Hifisem's experiment.

Claims (1)

Claim: Agent for the selective control of undesired plant growth, containing a Compound of the general formula (D wherein R is a 4-chlorophenyl, 2,4-dichlorophenyl, 2,4,6-trichlorophenyl-, 4-chloro-3,5-dimethylpheny! -, 4 - methylphenyl or 4 - methoxyphenyl - radical. (Kp. 2 mm / 175 to 182 C)