Certified Crop Advisor Practice Exam

Which fungicides are absorbed by the plant and distributed internally?

1. Contact fungicides

2. Systemic fungicides

3. Narrow spectrum fungicides

4. Protectant fungicides

The correct answer is: Systemic fungicides

Systemic fungicides are characterized by their ability to be absorbed by the plant and subsequently distributed internally throughout its tissues. This feature allows them to provide more comprehensive protection against fungal pathogens, as they not only protect the surface of the plant but also help in managing infections that may develop within the plant's system. Unlike contact fungicides, which remain on the surface and only affect pathogens that come into contact with them, systemic fungicides are drawn into the vascular system of the plant. This enables them to target pathogens that attempt to attack the plant from within. When applied, systemic fungicides can move through the xylem and phloem, ensuring that various parts of the plant benefit from their protective and curative properties. The other choices do not accurately describe the absorption and distribution characteristics of systemic fungicides. Protectant fungicides, for example, are typically used as a preventative measure and function primarily on the surface of the plant. Narrow spectrum fungicides focus on specific pathogens rather than having broad internal distribution capabilities. Thus, the defining quality of systemic fungicides being absorbed by the plant and distributed internally makes them essential for providing effective and lasting protection against fungal diseases.