Chlorpyriphos 50% EC Insecticide Uses

Chlorpyriphos 50% EC is a higher-concentration organophosphate insecticide (IRAC Group 1B), registered for use in India under the Insecticides Act, 1968, formulated as an emulsifiable concentrate (EC). It is used as a foliar spray against stem borer, leaf folder and bollworm complexes in paddy and cotton, and is also approved for pre- and post-construction termite protection of buildings. This page lists its mode of action, key benefits and the complete crop-wise recommended dosage as per the Central Insecticides Board & Registration Committee's (CIB&RC) official list of approved insecticide uses.

Which Problem Is This For? (Symptom Guide)

Not sure whether what you're seeing in the field matches this insecticide's use case? This guide helps match pest damage symptoms in paddy and cotton to this insecticide's approved crop-wise uses.

Mode of Action

Chlorpyriphos belongs to the organophosphate class of insecticides (IRAC Group 1B, acetylcholinesterase inhibitors). It works by inhibiting the enzyme acetylcholinesterase in the insect's nervous system, which normally breaks down the neurotransmitter acetylcholine after a nerve impulse. With this enzyme blocked, acetylcholine builds up at nerve synapses, causing continuous, uncontrolled nerve signalling that leads to paralysis and death of the target insect. Chlorpyriphos 50% EC acts through contact, stomach and fumigant action, giving it activity against chewing pests such as stem borer, leaf folder and bollworm larvae, with the fumigant action also giving it some reach against larvae sheltering inside rolled leaves or leaf sheaths. It has no systemic movement within plant tissue, so thorough spray coverage of the crop canopy is needed for good control. At the higher, non-agricultural 0.5–1.0% concentration, the same fumigant and contact action is used for pre- and post-construction termite protection of buildings.

Features & Benefits

• Higher-concentration (50% a.i.) formulation, giving flexibility to apply at a lower spray volume of product per acre compared with 20% EC formulations for the same target dose.
• Contact, stomach and fumigant action against key chewing pests of paddy and cotton — stem borer, leaf folder and bollworm complex.
• Also approved by CIB&RC for pre- and post-construction termite protection of buildings at a higher application concentration, in addition to its field-crop insecticidal uses.
• Emulsifiable concentrate (EC) formulation that mixes readily with water for uniform tank application.

Recommended Usage of Chlorpyriphos 50% EC Insecticide

The table below gives the recommended dose and water volume per acre for each crop and target pest, converted from the official rate published in the Central Insecticides Board & Registration Committee's (CIB&RC) list of approved insecticide uses (Government of India), which is expressed per hectare (1 ha ≈ 2.47 acres). Always spray in the recommended water volume for uniform coverage, and confirm against the current product label before use.

Doses above are converted from the official rate published in the CIB&RC's list of approved insecticide uses (Government of India), which states the rate in grams a.i./formulation per hectare; converted here to a practical per-acre spray-tank quantity (1 ha ≈ 2.47 acres) and rounded. The same CIB&RC list separately approves Chlorpyriphos 50% EC for non-agricultural, pre- and post-construction termite protection of buildings at a 0.5–1.0% spray concentration — this building-protection use is unrelated to the crop doses above and should be carried out only by a trained pest-control operator following the current product label. Always confirm the current product label and consult your local agricultural extension office before use.

How to Use

1. Identify your crop and target pest from the table above, and confirm the correct dose per acre and water volume.
2. Measure the required quantity of Chlorpyriphos 50% EC and mix it thoroughly into the spray tank water, agitating well before and during spraying so the emulsion stays evenly mixed.
3. Apply as a fine, uniform spray covering the entire crop canopy, taking particular care to reach the base of the tillers in paddy and the folded leaves where leaf folder larvae shelter.
4. For bollworm control in cotton, ensure good coverage of squares, flowers and young bolls, where the larvae enter and feed.
5. Spray during the early morning or late evening when pest activity and pollinator activity are both lower, and avoid spraying in hot, windy conditions or ahead of expected rain.
6. Repeat only if pest pressure resumes, allowing at least 10–15 days between sprays, and do not exceed 2–3 applications per season on the same crop to help manage resistance.

Precautions & Safety

• Wear appropriate PPE — mask/respirator, gloves, goggles and full-sleeved clothing — while mixing and spraying, since organophosphates are readily absorbed through the skin, and this is a higher-concentration (50%) formulation.
• Chlorpyriphos is highly toxic to bees, fish and other aquatic life; do not spray during crop flowering when bees are foraging, and avoid any drift or runoff into ponds, canals or water bodies.
• 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.
• Do not exceed the recommended dose or spray frequency; repeated, back-to-back use of the same insecticide class can lead to resistance development in target pest populations, so rotate with insecticides from a different mode-of-action (IRAC) group where possible.
• Respect the waiting period (PHI) given in the table above before harvesting the treated crop.
• Wash hands, face and any exposed skin thoroughly with soap and water after handling or spraying, and change out of contaminated clothing before eating, drinking or smoking.

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.