Pesticide Handling, Application, and Equipment
This domain tests the practical chain from storage and mixing through calibration, application, drift control, and container disposal. Expect questions on equipment checks, application rate math, and spill response.
Storage and mixing
- Store products in original labeled containers in a locked, ventilated area away from food, feed, and water. Use secondary containment for liquids and keep SDSs available.
- Wear label PPE when mixing and loading. Prevent back-siphoning by keeping the hose above the tank fill line or using an air gap.
- Measure with dedicated tools, triple-rinse or pressure-rinse containers, and add rinsate to the spray tank when the label allows.
- Transport containers closed and secured, outside the passenger compartment, with a spill kit available.
Calibration and application
Calibrate before each season and after nozzle changes. Check nozzle spacing and height, speed, pressure, and spray pattern. Replace worn or mismatched nozzles; pressure changes alter droplet size and drift potential. Record actual rate and area treated.
Worked example
One nozzle collects 16 fluid ounces in one minute. Nozzle spacing is 20 inches and speed is 4 mph. Convert 16 fl oz/min to 0.125 gallons per minute. Use: GPA = (GPM × 5940) ÷ (nozzle spacing in inches × speed in mph). GPA = (0.125 × 5940) ÷ (20 × 4) = 742.5 ÷ 80 = 9.3 GPA. If the label requires 10 GPA, adjust speed, pressure, or nozzle size, then recalibrate.
Drift and disposal
Reduce drift with appropriate nozzle type, lower boom height, buffer zones, and avoidance of high wind or temperature inversions. Oregon's terrain and inversions make off-target movement a real risk near sensitive crops and water. Dispose of rinsed containers according to state rules; never burn or reuse pesticide containers.
Traps that cost marks
Calibrating only with water and ignoring worn nozzles; raising pressure to change rate without checking droplet size; leaving rinsate where it can reach water; and storing products in unlabeled bottles.
Key points
- Store pesticides locked, ventilated, and in original labeled containers.
- Prevent back-siphoning during mixing and loading.
- Calibrate with the GPA formula and check nozzles for wear.
- Pressure changes affect both rate and drift.
- Triple-rinse containers and dispose of them properly.