SU1410859A3 - Method of controlling weeds - Google Patents

Abstract

This invention relates to the field of chemical methods for controlling weeds and unwanted vegetation. In order to enhance the herbicidal effect, the treatment of plants or soil is carried out by pyrazole derivatives of the general formula N CH-C (CN) C (NHa) -N (Ar), where Ar is 2-chloro-4-trifluoromethylphenyl, 2,6-dichloro-4 trifluoromethylphenyl, 2,3, 6-trichloro-4-trifluoromethylphenyl, 2,3, 5,6-tetrafluoro: 4-trifluoromethylphenyl. With doses of active substances of 0.0156-1 kg / ha, the method is effective for selectively controlling weeds in crops of cultivated plants, such as wheat. 2 tab. FROM

Description

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ate

with

 CN

This invention relates to chemical methods for controlling weeds and unwanted vegetation.

The aim of the invention is to enhance the herbicidal action of the weed control method based on the use of pyrazole derivatives.

Below are the active substances used in this method, and examples illustrating its effectiveness,

1.1- (2-Chloro-4-triAtoromethylphenyl) -4-cyano-5-aminopyrazole, m.p. 185-.

2.1- (2,6-Dichloro-A-trifluoromethyl-phenyl) -A-cyano-5-aminopyrazole, m.p.

les-iey c.

3.1- (2,3,6-Trekhlor-4-trifluoromethyl-phenyl) -4-cyano-5-aminopyrazole, m.p. .

4.1 - (2,3,5,6-Tetrafluoro-4-trifluoro methylphenyl) -4-cyano-5-aminopyrazole, m.p. 122-122.5 ° C.

Compounds 1-4 can be prepared by various known methods, for example, cyclization of the corresponding aryl hydrazinomethylene malononitriles when heated in ethoxyethanol.

Example 1, Dovskhodov processing.

Seeds of experimental plants were planted in prepared soil and treated with their active substances dissolved in acetone to various concentrations. After this, the seeds were crushed with a layer of finely ground sand of 25 mm thickness.

Seeds that were not treated and seeds treated with acetone served as controls.

For comparison, the known herbicidal active substance A - 1- (2,3,4-trichlorophenyl) -3-methyl-4-cyano-5-aminopyrazole was used.

After treatment, the pots with the seeds of the experimental plants were kept under greenhouse conditions with periodic watering.

Evaluation of the herbicidal action was carried out 19-28 days after treatment and its preparation in the minimum effective dose required for

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five

0

five

about

Q

five

0

90% damage to plants (SC) or for their complete destruction.

The results of the experiment are presented in table.1.

Example 2. Post-harvest processing.

Experimental plants grown under greenhouse conditions to a certain growth stage were treated with acetone solutions of active substances of various concentrations. After that, the plants continued to grow under greenhouse conditions for 19-28 days and evaluated the herbicidal effect as in Example 1 (for EDO,)

The results of the experiment are presented in table 2.

Specially conducted experiments on plants of bedstraw and wheat showed a high selectivity of compounds 1 and 2. At doses of 0.125–1 kg / ha, they almost completely hit the bedstraw and did not harm plants of wheat.

The data presented indicate a high efficiency of the proposed method. The method can be applied to selectively control weeds in crops of cultivated plants, such as wheat.

Claims (1)

Invention Formula A method of controlling weeds by treating them or the soil on which they grow, derivatives of pyrazole, characterized in that, in order to enhance the herbicidal effect, a compound of general formula nj is used as a derivative of pyrazole tg r; n-ag N where Ar is 2-chloro-4-trifluoromethylphenyl, 2,6-dichloro-4-trifluoromethyl-phenyl, 2,3,6-trichloro-4-tri-fluoromethylphenyl, 2,3,5,6-tetrafluoro-4- trifluoromethyl-phenyl, in the amount of 0.0156-1 kg / ha. Pre-emergence treatment Post-harvest processing Table 1 table 2