Topramezone

Product Name

Topramezone

Molecular Formula

C16H17N3O5S

CAS No.

210631-68-8

Molecular Structure

Molecular Weight

363.388

Properties

97% TC, 30% Topramezone SC

Appearance

White Powder

Impurity

3% max

Acetone In

3% max

PH

5.6-5.8

Melting Point

220.9-222.2℃

Bolling Point

590.5±60.0 °C at 760 mmHg

Flash point

310.9±32.9 °C

Relative Density

1.5±0.1 g/cm3

Solubility

(20C): Water 510+8.3mg/L (pH3.1)，Organic solvents (20CgL) dichloromethane 25-29, acetone, acetonitrile, ethyl acetate, toluene, methanol, 2-propanol, n-hexane, 1-octanol <10.

Usage

Topramezone is a benzoylpyrazolone herbicide. Post-emergence stem and leaf treatment results in absorption through the roots and young leaves, with translocation in plants from top to bottom, reaching the meristematic tissue. It inhibits 4-hydroxyphenylpyruvate dioxygenase (4-HPPD),suppresses plastoquinone, and indirectly hinders carotenoid biosynthesis, leading to disruption in chloroplast synthesis and function. Due to chlorophyll oxidation and degradation, sensitive weeds exhibit whitening upon germination, accompanied by growth suppression. Under photosynthesis, the affected symptoms resemble necrosis similar to yellowing disease. Sensitive target weeds display whitening symptoms 2-5 days after treatment, with plant death occurring within 14 days. It has a broad spectrum of weed control and is effective against annual weeds in cornfields.

Suitable Crops

Corn, sugarcane

Application

Topramezone is primarily used in cornfields, but BASF has started promoting its use in the sugarcane and orchard markets. The herbicidal spectrum of topramezone covers annual grasses and broadleaf weeds. Key monocot weeds include crabgrass, barnyard grass, foxtail, johnsongrass, wild oats, puncturevine, feather fingergrass, and more. Major broadleaf weeds include pigweed, dock, lamb's quarters, cocklebur, jimsonweed, nightshade, wild mustard, wild carrot, and groundcherry. However, due to its inherent properties, topramezone may not be as effective against sedge weeds, and its long-term control of broadleaf weeds is limited. It is recommended to mix it with other broadleaf herbicides like atrazine or mesotrione for improved control.

Topramezone

Advantage

1. Broad Weed Spectrum: Topramezone is effective against a wide range of weeds, including both grasses and broadleaf weeds. Difficult-to-control and resistant weeds such as crabgrass, barnyard grass, johnsongrass, wild oats, foxtail, pigweed, dock, nightshade, and lambsquarters can be controlled. When mixed with atrazine, it has a synergistic effect, providing weed control for over 35 days.

2. Fast Herbicidal Action: Topramezone acts quickly. After post-emergence application, sensitive weeds absorb it through their leaves and exhibit symptoms of toxicity within 2-4 days. This herbicidal speed is faster than that of other herbicides like mesotrione and sulcotrione, which typically take 5-7 days to show whitening symptoms, with death occurring around 10 days. It is currently one of the fastest herbicides for corn.

3. High Safety Profile: Corn has low sensitivity to topramezone, with minimal absorption and rapid metabolism. It can be used on most types of corn, including dent corn and sweet corn. It shows good selectivity for corn, including dent corn, sweet corn, and glutinous corn (while sulcotrione cannot be used on sweet corn). Topramezone can be applied even when corn has more than 6 leaves, providing a wider application window. In contrast, sulcotrione is typically applied at the 3-5 leaf stage.

4. Low Resistance Risk: No resistance to topramezone has been reported in weeds.

5. Minimal Impact on Crop Rotation: Topramezone has minimal impact on crop rotation. It can be safely used in various rotational crops, including soybeans, potatoes, cabbage, watermelons, and more. In contrast, sulcotrione-containing products can affect crops like cabbage and sugar beets for up to 18 months, and when used at high rates, may restrict the planting of crops like soybeans, sunflowers, potatoes, eggplants, and peppers for the same period.