Imazethapyr 240g/L SL Herbicide | Selective Post-Emergent Weed Control

Imazethapyr 240g/L SL (Soluble Liquid) is a systemic selective herbicide belonging to the imidazolinone family, designed for post-emergent control of annual and perennial grasses, broadleaf weeds, and sedges in soybeans, sugarcane, and fallow fields. As an acetolactate synthase (ALS) inhibitor, it disrupts amino acid biosynthesis, leading to weed growth cessation and death. The SL formulation offers high solubility in water, ensuring uniform mixing and efficient foliar absorption.

Technical Specifications

Parameter	Details
Active Ingredient	Imazethapyr (CAS No. 81335-77-5)
Chemical Class	Imidazolinone
Mode of Action	ALS inhibitor (HRAC Group 2)
Formulation Type	240g/L SL (Soluble Liquid)
Appearance	Clear to light yellow liquid
Solubility	Miscible in water (20°C)
pH Range	5.5–7.5
Density	1.0–1.1 g/cm³

Mode of Action

Systemic Uptake:
- Absorbed by leaves and roots, translocated via xylem and phloem to meristematic tissues.
Biochemical Inhibition:
- Blocks ALS enzyme, preventing synthesis of valine, leucine, and isoleucine.
Symptom Progression:
- 5–7 days: Chlorosis in new growth
- 10–14 days: Widespread necrosis and plant death

Application Guide

Crop/Setting	Target Weeds	Dosage (g ai/ha)	Application Timing
Soybeans	Crabgrass, foxtail, lamb’s – quarters	100–200	Post – emergent, weeds at 2–6 leaf stage
Sugarcane	Johnsongrass, yellow nutsedge	150–250	Post – emergent, weeds <30 cm tall
Fallow Fields	Perennial weeds (e.g., Canada thistle)	200–300	Post – emergent, active growth stage
Transgenic Crops	Tolerant soybeans, sugarcane	120–180	Foliar application during vegetative stage

Application Best Practices

Water Volume: 150–300 L/ha for optimal coverage.
Adjuvants: Add methylated seed oil (MSO, 1% v/v) to enhance leaf penetration.
Tank Mixes:
- With glyphosate for non – selective control in fallow areas
- With chlorimuron-ethyl for broadened broadleaf control in soybeans
Weather Conditions: Apply in cool, dry conditions (15–28°C); avoid spraying before rain.

Key Advantages

Broad – Spectrum Efficacy:
- Controls over 60 weed species, including herbicide – resistant biotypes (e.g., ALS – resistant pigweed).
Systemic & Residual Action:
- Translocates to roots for perennial control; provides 6–8 weeks of soil residual activity.
Crop Flexibility:
- Safe for use in imidazolinone – tolerant (IMI – tolerant) crops; ideal for rotation with non – IMI herbicides.
Low Mammalian Toxicity:
- LD₅₀ > 2000 mg/kg (rat); minimal risk to non – target organisms when used as directed.
Environmental Profile:
- Soil half – life 10–30 days; degrades via microbial action and photolysis.

Safety & Environmental Notes

Toxicity:
- Moderate toxicity to fish (LC₅₀ 1–10 mg/L); maintain 100 m buffer from water bodies.
- Low toxicity to bees (LD₅₀ > 100 μg/bee).
Crop Rotation Restrictions:
- Avoid planting sensitive crops (e.g., crucifers, beets) within 12–18 months of application.
Storage: Store at 5–30°C, protected from sunlight and freezing.

Packaging & Compliance

Standard Packs: 1L, 5L, 20L HDPE containers
Regulatory Support:
- COA, MSDS, and residue data for global markets (EPA, EU, APAC)
Shelf Life: 3 years under recommended conditions

FAQ

Can Imazethapyr 240g/L SL control perennial weeds?
Yes, effective against perennial weeds like Canada thistle and johnsongrass with proper dosage.
What is the pre – harvest interval (PHI)?
- Soybeans: 60 days
- Sugarcane: 90 days
- Fallow fields: No PHI (non – crop use)
Is it compatible with other herbicides?
Yes, but jar – test first. Compatible with most post – emergent herbicides except those in Group 2.
How to manage resistance in target weeds?
- Rotate with Group 15 (acetochlor) or Group 14 (fomesafen).
- Use tank mixes with different mode – of – action herbicides.
Can it be used in organic farming?
No, it is a synthetic herbicide; organic alternatives include mechanical weeding or mulching.

Field Performance

Soybean Trials in the US Midwest:
150 g ai/ha + MSO controlled 95% of crabgrass and lamb’s – quarters, increasing yield by 12%.
Sugarcane Trials in Brazil:
200 g ai/ha suppressed johnsongrass and yellow nutsedge, improving cane biomass by 15%.