Plant Protection (Entomology, Plant Pathology and Nematology)
Plant protection covers insect pests, diseases, nematodes and integrated pest management. The exam tests identification, symptoms, vectors, thresholds and safe pesticide use.
Core concepts
- IPM uses monitoring, economic threshold level, cultural, mechanical, biological and chemical methods, with chemicals as a last resort.
- The disease triangle requires a susceptible host, virulent pathogen and favourable environment.
- Fungi cause wilts, blights and mildews; bacteria cause wilts, spots and cankers; viruses cause mosaic and leaf curl and are often vectored by whitefly, thrips or aphids; nematodes cause root-knot galls and lesions.
- AP-relevant examples: fruit fly in mango, thrips in chilli, tea mosquito bug in cashew, Panama wilt in banana, bacterial wilt in solanaceous crops, citrus greening and coconut rhinoceros beetle/red palm weevil.
Worked example
A spray recommendation is 2 ml/L and the tank holds 200 L. Product needed = 2 × 200 = 400 ml. If the label gives 2 ml/L of commercial formulation, do not convert to active ingredient unless asked. Check the pre-harvest interval before harvest.
Traps
- Mixing active ingredient and commercial formulation.
- Calling a virus a fungus because symptoms look similar.
- Ignoring vectors in virus management.
- Using an ETL without its pest-density unit.
- Overlooking PHI and resistance rotation.