In short
Crop pest monitoring is a routine of walking each field at set growth stages, counting pests, diseases and weeds the same way every time, and writing the result down so that a spray decision rests on numbers.
The routine is the monitoring principle of integrated pest management, and it needs a record to be worth anything. Planva holds inspection templates, inspection tasks and phytosanitary reports with photos for this record.
What monitoring means
Monitoring answers one question: is there something in this field that justifies action, and where? A pest on a plant is not a reason to spray. A count that crosses a threshold is.
The EU framework for sustainable pesticide use, Directive 2009/128/EC, makes this explicit in Annex III. Harmful organisms must be monitored with adequate methods and tools where available, and the decision whether and when to treat rests on the monitoring results. The same annex asks for threshold values that are sound and defined for the region, the crop and the climate.
When to look: by growth stage
Extension guidance for wheat in the United States ties the visits to growth stages instead of the calendar. The table follows South Dakota State University, which recommends five stages. Timing in your region will differ, so use it as a pattern.
| Growth stage | What to check |
|---|---|
| Two leaves | Stand counts, weeds, diseases |
| Four to five leaves | Weeds, diseases, stand, colour, insects |
| Flag leaf | Weeds, insects, diseases |
| Flowering | Weeds, insects, diseases, and Fusarium head blight |
| Physiological maturity | Weeds that need control before harvest, harvest timing, problems for the next crop |
A general rule from the SARE guide on whole farm pest management is to look early and often, with weekly visits a good starting point. The same guide asks for extra attention on field edges, waterlogged areas and high-traffic areas.
How to walk a field
- Cover the whole field. Weeds and insects are patchy, so a sample from one corner says little. Walk a W, Z or zig-zag line across the field.
- Go where the problem lives. For pests tied to wet spots or access points, put more samples there. For insects that arrive from the edge, check the margins first to learn whether the interior needs sampling.
- Change the start. Begin at a different point on each visit and do not sample only the edges.
- Look at the plant. Check upper and lower leaf surfaces and growing points, and the soil for weed seedlings.
- Confirm what you found. Pests can look like beneficial insects, and similar pests may need different management. Check unclear cases with an extension agent, a field manual or a university department.
What to write down
| Field | What to record |
|---|---|
| Where and when | Field, point in the field, date |
| Crop stage | Growth stage on the day |
| What | Species of pest, disease or weed, and the life stage of insects |
| How much | Insects per plant, weeds per row, disease severity on a simple scale |
| Evidence | A photo of the symptom or the plant |
| Result | Action taken or decision to wait |
Record visits where you found nothing too. South Dakota State University advises writing down pest occurrence even when no control is needed, because next season the history tells you what to expect.
From a count to a decision
Neither the university guides nor the EU text gives one number that fits every farm. Thresholds depend on the pest, the crop, the stage and the region, and the guides send readers to local experts and production manuals. Take the threshold from the recommendations of your plant protection service or national extension body, write it in the record next to the count, and keep the decision with the agronomist.
How this works in Planva
- Inspection templates. Measurements, formulas, method steps and required photos.
- Inspection tasks. A task with an assignee, a My tasks section, and completion with a report.
- Phytosanitary reports. Diseases, pests and weeds, with weeds recorded by type, grass or broadleaf, plus intensity and height, inspection points and photos.
- Reference lists. Diseases, pests, units and indicator types.
Planva stores the inspection and its photos. It does not set thresholds or advise on treatment. Once a decision is made, the application goes into the spray records, and the product class is covered in the guide to pesticide toxicity classes.
Sources
Common questions
It is the routine of walking each field at set growth stages, counting pests, diseases and weeds by the same method, and recording the result. The record is what lets a spray decision rest on counts instead of habit.
The real Planva interface, shown with test data.
