CDFA Pest Prevention Plant Regulation Practice Exam

Which of the following would be least apt to carry the cedar-apple rust?

1. A. Juniper trees

2. B. Apple Trees

3. C. fresh fruit of apples from a bona fide commercial packing house

4. D. crabapple trees

The correct answer is: C. fresh fruit of apples from a bona fide commercial packing house

The correct choice is that fresh fruit of apples from a bona fide commercial packing house would be least apt to carry the cedar-apple rust. Cedar-apple rust is a fungal disease that requires two hosts to complete its life cycle: the cedar tree (often junipers) and certain apple or crabapple trees. The disease is primarily spread through spores produced on the cedar host, which can then infect the apple and crabapple species. While juniper and crabapple trees are directly associated with the lifecycle of cedar-apple rust, fresh fruit from a packing house is a processed product that has already been harvested and has little chance of harboring spores or the fungal pathogens that cause this disease. As a result, this fruit would be the least likely to contribute to the spread of cedar-apple rust. This reasoning emphasizes the ecological interactions between the specific plant hosts required for cedar-apple rust, delineating why the fresh fruit would not serve as a suitable vector or reservoir for the pathogen.