Certified Crop Advisor Practice Exam

Which type of fungicides are designed to kill specific pests?

1. Broad spectrum fungicides

2. Systemic fungicides

3. Narrow spectrum fungicides

4. Contact fungicides

The correct answer is: Narrow spectrum fungicides

Narrow spectrum fungicides are specifically formulated to target a limited range of fungal species. By being selective in their action, these fungicides reduce the risk of affecting non-target organisms, such as beneficial fungi or other aspects of the ecosystem. This specificity allows for more precise management of particular fungal diseases without disrupting the overall microbial community. In contrast, broad spectrum fungicides are designed to control a wide variety of fungal pathogens, which might be beneficial in certain situations but can also lead to a decrease in non-target microorganisms, potentially resulting in imbalances in soil health. Systemic fungicides work by being absorbed by the plant and providing internal protection against fungi, but they may not necessarily be limited to targeting specific pests; some have broad-spectrum activity. Contact fungicides primarily act on the surfaces of plants and typically require direct application to the pathogen. They can be broad or narrow in their effectiveness, depending on their formulation and intended use. Thus, narrow spectrum fungicides are most aligned with the objective of targeting specific pests, making them the correct choice in this context.