Propargite: A Selective Acaricide for Mite Control

Definition:
Propargite is a non-systemic acaricide primarily used to control mites on crops such as cotton, fruits, vegetables, and ornamental plants. It is highly effective against both adult mites and nymph stages but does not target insect pests.

Chemical Characteristics of Propargite:

• Chemical Name: 2-(4-tert-butylphenoxy) cyclohexyl prop-2-yne-1-sulfonate

• Molecular Formula: C₁₉H₂₆O₄S

• Molecular Weight: 350.47 g/mol

• Appearance: Amber or yellow-brown liquid (technical grade).

• Solubility: Insoluble in water but soluble in organic solvents.

• Stability: Stable under normal conditions but degrades under strong acidic or alkaline conditions.

Mode of Action:

Propargite works as a contact acaricide, inhibiting the energy production (oxidative phosphorylation) in mite cells. This leads to paralysis and eventual death. It primarily targets mites feeding on the plant surface.

Uses and Applications:

1. Agricultural Use:

   • Effective against Tetranychid mites (spider mites) in crops like cotton, citrus, apples, beans, tea, and ornamentals.

   • Suitable for use where mites are resistant to organophosphates or carbamates.

2. Selectivity:

   • Targets mites specifically without significant impact on most insect pests or beneficial insects.

3. Residual Activity:

   • Provides long-lasting control with strong adherence to plant surfaces.

Benefits of Propargite:

• High Efficacy: Rapid knockdown of mite populations.

• Resistance Management: Effective against resistant mite strains.

• Crop Safety: Minimal phytotoxicity when used as directed.

• Extended Residual Control: Reduces the frequency of applications.

Limitations:

• Not Systemic: Only effective via direct contact; thorough spray coverage is required.

• Specificity: Targets mites only; does not control insect pests.

• Toxicity: Moderately toxic to humans and highly toxic to aquatic organisms.

Recommended Application:

• Dosage: 500–1000 mL per hectare (varies with crop and mite infestation level).

• Timing: Apply at early signs of mite infestation for best results.

• Precautions:

  • Wear protective clothing and gloves during application.

  • Avoid spraying during windy conditions to reduce drift.

  • Do not mix with highly alkaline materials.

Storage and Handling:

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

• Shelf Life: 2–3 years if stored properly.

• Precautions: Keep away from food, feed, and children; avoid contamination of water sources.

FAQ on Propargite:

Q1: What pests does propargite control?
A1: Propargite is specific to mites, particularly spider mites, and does not affect insects.

Q2: Is it systemic or contact-based?
A2: It is a contact acaricide, requiring good spray coverage for effectiveness.

Q3: Can it be mixed with insecticides?
A3: Yes, it can often be tank-mixed with compatible insecticides, but compatibility testing is recommended.

Q4: Is propargite safe for pollinators?
A4: Generally safe for bees and pollinators due to its selectivity, but spraying should still be avoided during bloom.