Trade name(s) Many

Manufacturer(s) Corteva, Helena, Nufarm, and others

Formulation(s) Numerous acids, salts (amines usually), and esters. Sold as liquids, water-soluble powders, dusts (seldom used due to drift hazard), granules, and pellets.

Remarks A selective, foliar-absorbed, translocated phenoxy herbicide used mainly in postemergence applications. 2,4-D is effective against many annual and perennial broadleaf weeds. Ester formulations are the most volatile, the amines least volatile. Plants are most susceptible when they are young and growing rapidly.

Water solubility 900 ppm

Storage conditions Amine formulations are relatively stable, whereas esters depend on emulsifying system. Read each product label carefully.

Acute toxicity LD50 - 300 to 1,000 mg/kg

Action in plant Mimics natural plant hormones.

Site of action Group 4: synthetic auxin

Chemical family Phenoxy acetic acid

Koc Average is 20 mL/g for the acid and DMA salt, and 100 mL/g (estimated) for esters of the oil-soluble amine