Application Equipment, Calibration, and Application Techniques
Calibration is the core skill
Candidates must be able to explain why calibration precedes every application and how to calculate output. Know the relationship: output per area depends on nozzle flow, spray pressure, speed and swath width. Learn the common calibration methods (measuring output over a known area or time, and the nozzle-flow method) and be able to perform a simple calculation. Understand that doubling speed roughly halves output per area if pressure and nozzle are unchanged, and that changing pressure changes droplet size and drift potential as well as rate.
Know nozzle types and their uses: flat fan for broadcast, even fan for overlapping passes, hollow cone for penetration and coverage of foliage, and air-induction or drift-reduction nozzles for coarse droplets. Traps: increasing pressure to increase rate (it also increases drift and can change coverage), and assuming a larger nozzle is always better. Worn nozzles deliver uneven patterns and higher output; replace them.
Technique and equipment care
Learn correct technique: proper boom height, overlap, travel speed, spraying when wind is within label limits, and avoiding application near sensitive areas. Understand that droplet size, boom height and wind determine drift. Know the importance of rinsing and maintaining equipment, and that a poorly rinsed tank can injure a sensitive crop.
Rule of thumb: calibrate at the start of the season, after any nozzle or pressure change, and whenever a new product or carrier is used; record the calibration figures.
Worked example: a sprayer applies 200 L/ha at 4 km/h. Increasing speed to 8 km/h with the same nozzle and pressure gives roughly 100 L/ha, which is below the labelled rate. The correct fix is to recalibrate and adjust nozzle or pressure to restore the labelled output, not to accept the lower rate.