Mesotrione OD Herbicide Specification

1. Product Description

Mesotrione OD is a new-generation triketone herbicide, specifically designed for both pre-emergence and post-emergence control of annual broadleaf weeds and certain grass weeds in cornfields. It effectively targets major field broadleaf weeds, including burdock, lambsquarters, amaranth, dock, nightshade, and ragweed, as well as seedling-stage grass weeds such as barnyardgrass, crabgrass, setaria, and arm grass.

2. Mode of Action

Mesotrione OD exerts its herbicidal effect by acting as a potent inhibitor of HPPD (4-hydroxyphenylpyruvate dioxygenase)—an enzyme widely distributed in various organisms, which catalyzes the initial reaction in the biosynthesis of plastoquinone and tocopherol.

Key characteristics of this enzyme: In phosphate buffer, its optimal pH value is 7.3, while it maintains activity over a relatively broad pH range. When the temperature increases from 23 °C to its optimal operating temperature of 30 °C, the enzyme’s activity doubles.

The inhibition of HPPD leads to the accumulation of tyrosine and depletion of plastoquinone in plant meristems, ultimately resulting in plant bleaching and gradual death.

3. Prevention and Control Targets & Application Guidelines

3.1 Control Targets

Mesotrione OD provides reliable pre-emergence and post-emergence control of annual broadleaf weeds and certain grass weeds, including:

• Broadleaf weeds: burdock, lambsquarters, amaranth, smartweed, nightshade, and giant ragweed;
• Seedling-stage grass weeds: barnyardgrass, crabgrass, setaria, and arm grass.

3.2 Application Methods & Dosage

It can be applied as a soil surface treatment before corn germination or as a foliar and stem spray after seedling emergence. The herbicide is absorbed through seeds, young roots, buds, and leaves, and translocated throughout the plant via the xylem and phloem.

Recommended application dosage:

• Pre-emergence: 200–300 g/hm²;
• Post-emergence: 100–150 g/hm².