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Chlorpyrifos 50% + Cypermethrin 5% EC

The chlorpyrifos 50% + cypermethrin 5% EC pre-mix is a dual-mode broad-spectrum insecticide sold in India as Nagarjuna Cannon, Major 555 and many generic equivalents. It pairs an organophosphate with a Type-II pyrethroid for combined contact, stomach and residual activity.

Composition / Active ingredient

  • Composition: Chlorpyrifos 50% + Cypermethrin 5% EC
  • Chemical classes: Organophosphate + Type-II pyrethroid
  • Naming note: Tata Rallis "Nagata" is a different ethion 40% + cypermethrin 5% EC pre-mix, not chlorpyrifos-based.

Mode of action

The mixture combines two unrelated nervous-system modes:

  • Chlorpyrifos inhibits acetylcholinesterase (AChE), allowing acetylcholine to accumulate at synapses and over-stimulate nerves. IRAC Group 1B.
  • Cypermethrin modulates voltage-gated sodium channels, prolonging the open state and causing prolonged depolarisation. IRAC Group 3A.

Both actives are non-systemic and work by contact and stomach action on the surface they coat.

Target use and dose

Registered uses cover bollworms, leaf folder, stem borer, jassids, aphids, whitefly and termites in cotton, paddy, chilli, vegetables, soybean and mango. Field dose is typically ~500 ml/acre. The combination is favoured for "rescue" sprays on heavy borer outbreaks where both rapid knockdown (pyrethroid) and stomach toxicity (OP) are desired.

Safety and regulatory status

Chlorpyrifos has been restricted on several crops worldwide due to neurotoxicity concerns; the pyrethroid component is highly toxic to fish and bees. Pre-harvest interval and water-body buffer zones on the label must be respected. As a hard-chemistry mix it is generally reserved for outbreaks; rotation with diamides such as Ampligo preserves softer chemistry.

See also: Acephate, Bifenthrin, Monocrotophos Phaskil, Ampligo.

References

  1. Chlorpyrifos 50 + Cypermethrin 5 EC. NaPanta.
  2. Tata Rallis Nagata (Ethion + Cypermethrin). Cultree.