Imazethapyr 10% SL Herbicide Uses

Imazethapyr 10% SL is an imidazolinone herbicide registered for use in India under the Insecticides Act, 1968, formulated as a soluble liquid (SL). It is a selective, early post-emergence herbicide registered for soybean, groundnut, black gram (urad), green gram (moong) and red gram (arhar), and for direct-seeded imazethapyr-herbicide-tolerant rice, controlling both grassy and broadleaf weeds. This page lists its mode of action, key benefits and the recommended dosage per crop as per the official Central Insecticides Board & Registration Committee (CIB&RC) list of approved herbicide uses (Government of India).

Which Weeds Does This Control? (Field Identification Guide)

Not sure whether the weeds in your field match this herbicide's use case? This guide helps match weed identification to this herbicide's approved crop-wise uses.

Mode of Action

Imazethapyr belongs to the imidazolinone family (HRAC Group 2 / Group B) and works as an ALS (acetolactate synthase) inhibitor. It is absorbed through both the leaves and the roots of weeds and moves to the growing points, where it blocks the ALS enzyme needed to make the branched-chain amino acids valine, leucine and isoleucine. Without these amino acids, the weed stops growing within a few days; the growing points turn yellow to reddish-purple and die, followed by gradual death of the whole weed over 1–3 weeks. Tolerant crops such as soybean, groundnut and the registered pulses (and specially bred imazethapyr-tolerant rice varieties) break the herbicide down quickly, which is what makes it selective.

Features & Benefits

• Controls both grassy and broadleaf weeds — including Echinochloa, Commelina, Euphorbia, Amaranthus and Digera — in a single early post-emergence spray.
• Registered across soybean, groundnut and three major kharif pulses (black gram, green gram, red gram).
• Leaf and root uptake gives some residual activity against later-germinating weeds.
• Low use rate per acre and a soluble-liquid formulation that mixes easily in water.

Recommended Usage of Imazethapyr 10% SL Herbicide

The table below gives the recommended dose, water volume and waiting period per acre for each crop, converted from the CIB&RC-registered per-hectare rate — see the note below the table for conversion details. CIB registers this herbicide with an MSO (methylated seed oil) adjuvant added at 2 ml per litre of spray water. Always confirm against the current product label before use.

Figures above are converted from the CIB&RC-registered per-hectare rates (1 ha ≈ 2.47 acres): Soybean — 75–100 g a.i./ha, 750–1000 ml formulation/ha; Groundnut — 100–150 g a.i./ha, 1000–1500 ml/ha; Black gram, Green gram and Red gram — 75 g a.i./ha, 750 ml/ha; each with MSO adjuvant @ 2 ml per litre of water and 375 L water/ha. Direct-seeded imazethapyr-herbicide-tolerant rice — 100 g a.i./ha, 1000 ml/ha, 375–500 L water/ha. Always confirm the current dose on your specific product's label before use.

How to Use

1. Confirm your crop is one of the registered crops above and identify the weeds present using the guide.
2. Spray when the weeds are young — at the 1–2 leaf stage, usually 7–14 days after sowing in soybean and groundnut. Older, bigger weeds are much harder to control.
3. Fill the spray tank half-full with clean water, add the measured herbicide, then add the MSO adjuvant (2 ml per litre of water), and top up to the full volume while stirring.
4. Use a knapsack sprayer with a flat-fan or flood-jet nozzle and cover the weeds uniformly; avoid overlapping passes.
5. The soil should have adequate moisture at the time of spraying; spray in calm weather and avoid spraying if rain is expected within a few hours.
6. Do not disturb the soil (hoeing or weeding) for about 10 days after spraying.

Precautions & Safety

• Use on rice only in direct-seeded imazethapyr-herbicide-tolerant rice varieties — it will severely damage or kill normal (non-tolerant) rice.
• Imazethapyr can persist in the soil; check the label for rotational-crop restrictions before sowing a sensitive crop (such as some vegetables, mustard or sugar beet) in the treated field.
• Avoid spray drift onto neighbouring sensitive crops, and clean the sprayer thoroughly after use.
• Imazethapyr is an ALS inhibitor (HRAC Group 2); avoid using it every season on the same field and rotate with herbicides of a different group to slow weed resistance.
• Wear appropriate PPE — mask, gloves, goggles and full-sleeved clothing — while mixing and spraying.
• Respect the waiting period (PHI) for each crop given in the table above before harvest.
• Store in the original, tightly closed container in a cool, dry place away from direct sunlight, food and feed, and out of reach of children and livestock.

Brand names mentioned on this page are registered trademarks of their respective owners and are referenced here for identification purposes only; FarmMate is not affiliated with or endorsed by these brands. This page is for general information only — always consult your local agricultural extension office and confirm the current product label before use.