Illinois Field Crop Applicators Practice Test

Contact fungicides are fungicides that:

1. Penetrate the plant tissue

2. Remain on the surface of the plant

3. Are absorbed by the roots

4. Target specific pathogens within the plant

The correct answer is: Remain on the surface of the plant

Contact fungicides are designed to remain on the surface of the plant. Their mode of action primarily focuses on creating a protective barrier that prevents fungi from penetrating the plant's surface and establishing infections. This characteristic makes them effective for managing diseases that infect the outer tissues of plants. Unlike systemic fungicides, which are absorbed through plant tissue and can move within the plant to provide internal protection, contact fungicides do not penetrate the plant. Their effectiveness relies on thorough coverage during application because they need to come into direct contact with the pathogens on the surface to be effective. This type of fungicide is particularly useful in preventing fungal diseases on crops by ensuring that the pathogen cannot attach and establish itself on the plant’s exterior.