2，4-D

2,4-D is a phenoxy carboxylic acid selective herbicide discovered and synthesized by Amchem (USA, now part of Syngenta) in 1942 and put into practical application in 1946. It is the world's first synthetic organic herbicide.

Mode of Action:
2,4-D is classified as a Group O herbicide by the Herbicide Resistance Action Committee (HRAC) (WSSA Group 4) and acts as an auxin mimic. Its mechanism involves mimicking natural plant auxins (such as indole-3-acetic acid). At high concentrations, it promotes abnormal increases in nucleic acid and protein synthesis in weed stem tissues, restores the division capability of mature cells, causes disordered cell division and abnormal growth, ultimately leading to weed death. 2,4-D is systemic; after being absorbed by roots and leaves, it translocates via the phloem and xylem, inhibiting nutrient transport. At low concentrations, it can act as a plant growth regulator to promote growth and prevent flower and fruit drop; at high concentrations, it exhibits growth inhibition and herbicidal properties, which are particularly evident in broadleaf plants. The activity order is typically: ester > acid > salt.

Target Weeds and Application Scope:
(1) Applicable Crops: Rice, corn, wheat, barley, oats, sorghum, sugarcane, pasture, and other grass crops. Strictly prohibited for use in sensitive broadleaf crops such as cotton, legumes, and fruit trees.
(2) 2,4-D is primarily used to control annual and perennial broadleaf weeds and sedges, such as black nightshade, lambsquarters, commelina, redroot pigweed, cocklebur, field bindweed, horsetail, velvetleaf, amaranth, etc. It is ineffective against grass weeds. Common dosages vary depending on the crop and weed species. Due to its volatility and drift characteristics, traditional butyl ester formulations have been restricted or banned in many countries, and derivatives with lower volatility, such as isooctyl ester, are currently recommended.

Main Formulations:
2,4-D 720 g/L SL
Florasulam 6.25 g/L + 2,4-D 300 g/L SE