Merpan

The Technical Basis of Contact Protection

Merpan, produced by the Israeli company Makhteshim Chemical Works Ltd., is a classic fungicide based on captan (a phthalimide derivative). Its efficacy is rooted in its mode of action: the product does not penetrate the plant but instead creates a dense protective film on the surface, blocking the germination of pathogen spores. This makes it an essential tool in anti-resistance management programs.

Key Application Aspects

• Action Mechanism: It inhibits the respiration and cell division processes of fungi by suppressing the activity of enzymes containing sulfhydryl groups. Unlike systemic products, Merpan poses a very low risk of inducing resistance in pathogens.
• Preparation Technology: Available as a wettable powder, which requires strict adherence to the preparation protocol for the stock solution to ensure uniform coverage of the leaf blade.
• Treatment Regulations: Up to 4 applications per season are permitted. Given its contact nature, the quality of spraying is critical: the product must completely cover the surface of the apple trees, pears, tomatoes, or grapevines. The pre-harvest interval is 20–30 days.

The application rate varies from 2.0 to 3.0 L/ha depending on the phytosanitary situation and the crop. Merpan demonstrates high effectiveness against scab, anthracnose, various rots (white, gray, sclerotiniosis), and downy mildew. Due to its Class 2 hazard rating, strict adherence to personal protective equipment is required during handling to prevent contact with mucous membranes and skin.