What characterizes contact fungicides?

Contact fungicides are characterized by their mechanism of action, which requires direct contact with the fungus present on the plant. These types of fungicides operate by creating a protective barrier on the surface of the plant, inhibiting fungal growth and preventing infections when they are applied. For contact fungicides to be effective, they need to be applied to the affected areas of the plant where the fungus is located, as they do not penetrate plant tissues or get absorbed into the plant system like systemic fungicides do.

This action ensures that as the fungal spores come into contact with the fungicide, they are effectively neutralized. In contrast, the other options do not accurately describe the properties of contact fungicides. They do not penetrate plant tissues or get absorbed through the roots, and their effectiveness is not specifically dependent on rainfall, although moisture can aid in the distribution on the plant surface.