MCPA калий

Description

MCPA potassium is the potassium salt of 2-(4-chloro-2-methylphenoxy)acetic acid, a water-soluble commercial form of the herbicide MCPA. Chemical group - phenoxyacetic acids, mechanism - synthetic auxin. In solution, the salt dissociates, and the MCPA anion enters the plant, which is integrated into hormonal regulation instead of natural auxin. The cells of the dicotyledonous weed begin to divide and stretch uncontrollably, the stems and petioles curl, the phloem breaks, and the transport of assimilates to the root stops. Cereals are resistant to phenoxyauxines, so the drug is selective in grains and cereal pastures. Salt forms, unlike ethereal ones, are practically non-volatile, which reduces the risk of vapor drift to neighboring crops. Known under the names Fernimin 4, Agroxon 4, K MCPA, potassium salt MCP.

Basic Attributes

• CAS No: 5221-16-9 (additional registration number 117266-12-3)
• Chemical formula according to the card: C9H9ClO3,K; in the PubChem database it is recorded as C9H8ClKO3
• Molecular weight: 238.71
• Exact weight: 237.9799033
• PubChem CID: 23682017
• PSA specs: 49.4
• Systematic name: potassium 2-(4-chloro-2-methylphenoxyacetate

Form properties

• Salt form - soluble in water, used in the form of aqueous concentrates
• Volatility is low: unlike MCPA esters, the salt produces virtually no vapors
• For MCPA free acid, the solubility in water is 825 mg/l
• The half-life of MCPA in soil is 24 days; the rate of decomposition depends on temperature and humidity

Scope of application

Active ingredient in post-emergence herbicides against annual and perennial broadleaf weeds:

• cereal grains, primarily wheat
• cereal pastures and hayfields
• target weeds: thistle, sorrel and other dicotyledonous species

Information on the active substance

Development of MCPA began in 1936 at the ICI Jealott's Hill research center. The first publication in the open scientific press was made by Slade, Templeman and Sexton in 1945, and the substance went on sale to British farmers in 1946. Synthesis occurs from 2-methyl-4-chlorophenol by treatment with chloroacetic acid in dilute alkali - a nucleophilic substitution reaction. The potassium salt is obtained by neutralizing the acid with potassium hydroxide or potassium carbonate.

Toxicity and ecology

• MCPA is moderately toxic to mammals and aquatic organisms
• Treatment is carried out in compliance with water protection zones; entry into water bodies is unacceptable.

Storage and transportation

• The warehouse is dry, ventilated, protected from direct sun and freezing
• The container is tightly closed: salt is hygroscopic, aqueous concentrates should not be allowed to separate
• Storage and transportation separately from food, feed and seed