Which are the recognized principles of disease control?

• A. Exclusion, Reduction, Protection, Resistance.
• B. Eradication, Elimination, Quarantine, Monitoring.
• C. Suppression, Containment, Removal, Restoration.
• D. Prevention, Cure, Vaccination, Surveillance.

Answer: (A)

The four recognized principles of disease control provide a practical framework for keeping pathogens out and limiting their impact: Exclusion, Reduction, Protection, and Resistance.

Exclusion means preventing the pathogen from entering or establishing in a stand. This is about stopping new infections from starting, using measures like cleaning equipment and tools, restricting movement of material from diseased areas, and inspecting plants before they’re moved or planted.

Reduction focuses on lowering the amount of pathogen present and the chances of spread. This includes removing or destroying infected material, practicing sanitation to cut down inoculum sources, and timing operations to minimize opportunities for transmission.

Protection involves shielding healthy trees from infection even when the pathogen is present. Examples are applying protective sprays during vulnerable periods, using physical or cultural barriers, improving stand vigor through proper spacing and thinning, and implementing resistant management practices to reduce exposure.

Resistance centers on using host genetic factors to limit disease impact. This means selecting or deploying trees that are resistant or tolerant to the pathogen, and incorporating resistant varieties or genotypes into management plans.

Other options mix actions or outcomes (like eradication, quarantine, vaccination, or surveillance) that aren’t grouped as the four fundamental principles, so they don’t fit the standard framework as cleanly.