Profenofos: A Broad-Spectrum Organophosphate Insecticide

Definition:
Profenofos is an organophosphate insecticide and acaricide widely used in agriculture to control a broad range of chewing and sucking insect pests and mites. It is known for its dual action on contact and ingestion, making it effective for pest management in various crops.

Chemical Characteristics of Profenofos:

• Chemical Name: O-(4-bromo-2-chlorophenyl) O-ethyl S-propyl phosphorothioate

• Molecular Formula: C₁₁H₁₅BrClO₃PS

• Molecular Weight: 373.64 g/mol

• Appearance: Amber to light brown liquid (technical grade).

• Solubility: Slightly soluble in water; soluble in organic solvents such as xylene and acetone.

• Stability: Stable under normal storage conditions; degrades in alkaline environments.

Mode of Action:

Profenofos inhibits the enzyme acetylcholinesterase (AChE) in insects, causing accumulation of acetylcholine at nerve synapses. This overstimulates the nervous system, leading to paralysis and death.

Uses and Applications:

1. Agricultural Use:

   • Effective against bollworms, armyworms, aphids, jassids, and mites.

   • Commonly used on cotton, soybean, vegetables, fruits, maize, and tobacco.

2. Dual Activity:

   • Functions as both an insecticide and acaricide.

   • Controls pests resistant to pyrethroids and other insecticides.

3. Application Method:

   • Applied via foliar spray for direct contact and ingestion by pests.

Benefits of Profenofos:

• Broad-Spectrum Control: Effective on both chewing and sucking pests.

• Dual Action: Works on contact and ingestion for faster results.

• Resistance Management: Useful in rotation to manage insecticide resistance.

• Residual Activity: Provides prolonged pest control under field conditions.

Limitations:

• Toxicity Concerns: Highly toxic to humans, animals, and beneficial insects if mishandled.

• Environmental Impact: Harmful to aquatic life and non-target organisms.

• Odor: Has a strong and pungent smell, which may cause discomfort during application.

Recommended Application:

• Dosage: Typically 500–1000 mL per hectare (depending on crop and pest severity).

• Timing: Apply at early pest infestation stages for maximum effectiveness.

• Precautions:

  • Wear protective equipment during mixing and spraying.

  • Avoid inhalation and skin contact.

  • Do not spray near water sources or flowering crops to protect pollinators.

Storage and Handling:

• Storage: Keep in original, sealed containers in a cool, dry, well-ventilated area.

• Shelf Life: 2–3 years if stored under recommended conditions.

• Precautions: Keep away from food, feed, and children.

FAQ on Profenofos:

Q1: What pests does profenofos control best?
A1: It is effective against bollworms, aphids, mites, jassids, and caterpillars in cotton and other crops.

Q2: Is profenofos systemic or contact-based?
A2: It is primarily a contact and stomach poison, not systemic.

Q3: Is it safe for beneficial insects?
A3: No, profenofos is toxic to beneficial insects like bees and predators; avoid spraying during bloom.

Q4: Can it be mixed with other insecticides?
A4: Yes, it is often tank-mixed with other insecticides, but compatibility tests are advised before use.