What are Metalaxyl and Mefenoxam classified as?

Metalaxyl and Mefenoxam are classified as systemic fungicides. This classification is based on their ability to be absorbed by the plant and translocated throughout its tissues, allowing them to act on pathogens not only on the plant's surface but also those that may be located within the plant structure itself. Systemic fungicides provide a more comprehensive form of protection against fungal diseases because they can reach parts of the plant that are not directly exposed to the application.

These fungicides specifically target certain types of fungi and are particularly effective against diseases caused by Oomycetes, such as downy mildew and root rot diseases. This capability makes them valuable tools in agriculture and horticulture, where managing soil-borne pathogens and foliar infections is crucial for crop health and yield.

In contrast, non-systemic fungicides typically act only on the surface of the plant and do not penetrate into the tissue, making them less effective for controlling internal infections. Other options like broad-spectrum herbicides and contact insecticides do not apply here, as they pertain to weed control and insect management rather than the treatment of fungal diseases.