Pest Identification and Control
This domain tests integrated pest management: identifying the pest and life stage, monitoring, using thresholds, choosing controls, and preventing resistance. It also covers pesticide classifications and formulations as tools within an IPM program.
IPM sequence
- Identify the pest before treating. A grass weed has parallel veins and a fibrous root system; a broadleaf weed has netted veins and a taproot. Mites are not insects, so insecticides may fail.
- Monitor with sweeping, traps, scouting, or degree-day models. Treat only when the pest is present at a stage and level that justifies action.
- Use cultural, mechanical, biological, and chemical controls in a deliberate order. Preserve beneficial insects and pollinators where possible.
- For disease, distinguish abiotic injury from pathogen symptoms. Fungicides are often preventive, not curative, so timing relative to infection matters.
- Rotate mode-of-action groups, not just product names. Use full label rates and avoid repeated sublethal exposure that selects resistant individuals.
Formulations and labels
Emulsifiable concentrates, wettable powders, dry granules, and suspension concentrates behave differently in the tank. Check compatibility before mixing, use the label's specified adjuvants, and confirm the crop, site, and pest are on the label.
Worked example
A grower reports that the same herbicide has failed for three seasons. Before increasing the rate, confirm the weed species and growth stage, check whether the application missed the susceptible stage, and review the field history. If susceptible weeds survive a correct full-rate application, suspect resistance. Rotate to a different mode-of-action group and integrate cultural control rather than raising the rate, which can select harder-to-control populations.
Traps that cost marks
Calendar spraying without monitoring; misidentifying weeds or insects; using an insecticide for mites; ignoring beneficials; mixing products without a compatibility check; and treating a label crop/site restriction as a suggestion.
Key points
- Identify the pest and life stage before selecting a control.
- Monitor and use thresholds instead of calendar treatments.
- Rotate mode-of-action groups to manage resistance.
- Mites are not insects; product choice differs.
- Confirm crop, site, and pest are on the label.