Fungicides form a protective film on plant leaves to do what?

Fungicides form a protective film on plant leaves primarily to kill fungus spores before they can enter plant cells. This is crucial in preventing fungal infections that can lead to plant diseases. The action of fungicides typically involves creating a barrier that irritates or disrupts the spores or mycelium of the fungi, preventing them from taking hold and penetrating the plant tissues.

By effectively managing these fungal pathogens, fungicides help to protect the overall health of the plant, ensuring that it can maintain its growth and development without the detrimental effects of disease. This function underscores the importance of fungicides in integrated pest management, as they are a tool for safeguarding crops from the damaging effects of fungi.