Pre-spray checklist

Most application problems — drift complaints, poor control, crop injury, equipment failures — can be traced to something that could have been checked before the job started. A short, consistent checklist catches them. Adapt the list below to your equipment, your crops and your local regulations.

1. The label

• Read the current label for the product and the crop: rate, water volume, droplet class, timing, crop stage and pre-harvest interval.
• Note weather conditions the label sets: wind range, temperature limits, inversion restrictions, rainfast period.
• Note buffer zones, restrictions near water and sensitive areas, and pollinator statements.
• Check tank-mix compatibility and the mixing order if more than one product is involved.
• Check whether aerial or drone application is permitted, if relevant — see agricultural drone rules by country.

2. People and protective equipment

• Wear the PPE the label requires, in good condition.
• Have clean water, soap and a first-aid kit on hand, and know the emergency contacts.
• Make sure every operator is trained and, where required, licensed.

3. Equipment and calibration

• Inspect nozzles, filters, hoses and seals for wear, blockages and leaks.
• Calibrate: check output per nozzle and the actual application rate at your working speed and pressure.
• Confirm the nozzle type and pressure give the droplet class you need — see droplet size and nozzles.
• Set boom height, or drone flight height and swath, to the manufacturer's recommendation.
• For drones: propellers, arms, batteries and charging plan, compass and return-to-home point, RTK connection.

4. The weather window

• Wind: light and steady, within the label's range, blowing away from sensitive areas. Check gusts.
• Thermal inversion: not present. Be especially careful at dawn, dusk and at night.
• Delta T: ideally 2–8 °C.
• Humidity and dew: leaves not wet where the label advises against it.
• Rain: no rain expected within the rainfast period.
• Temperature: within label limits; weeds actively growing.
• For drones: Kp index and satellites — see Kp index, RTK and GNSS.
• Confirm the forecast on site with your own readings before starting.

5. The field and its surroundings

• Map buffer zones, water bodies, wells, homes, schools, gardens and susceptible crops.
• Know which way is downwind and what lies there.
• Tell neighbours and beekeepers in advance where local rules or good practice call for it.
• Check the take-off and landing area for obstacles, power lines and bystanders if flying a drone.

6. During and after the application

• Keep an eye on wind changes and stop if conditions move out of range.
• Clean the equipment as the label directs and dispose of rinsate and containers correctly.
• Observe re-entry intervals and mark treated fields where required.

7. Records

Many jurisdictions require application records. Record at least the date and time, field, crop, product and rate, water volume, equipment and nozzles, operator, and the weather at the time of application — wind speed and direction, temperature, humidity and Delta T. Good records also help explain a result later.

In PulveCast

PulveCast includes customisable pre-operation checklists, with default lists for drones and for ground equipment, and gives an hour-by-hour safe, caution or do-not-spray verdict for the weather part of the list.

More guides

• Delta T for spraying: what it is and why 2 to 8 °C
• Delta T chart: how to read it
• Thermal inversion and spraying
• Spray drift: causes and how to reduce it
• Wind speed for spraying
• The best time of day to spray
• Humidity and dew point for spraying
• Rain and spraying: rainfast periods and forecasts
• Temperature and spraying
• Droplet size and nozzle selection
• Weather for drone spraying
• Kp index, RTK and GNSS for spray drone operators