For optimal performance, a sprayer should be calibrated before which of the following?

Calibrating a sprayer before each spraying job is crucial to ensure that the equipment operates efficiently and applies the correct amount of product. Each job may have different requirements based on factors such as the type of product being used, the application rate, and the environmental conditions. This calibration process helps in achieving uniformity in application, minimizes waste, and protects the environment by preventing over-application, which could lead to runoff or damage to non-target areas.

While it is important to calibrate a sprayer for the first use, at the end of the season, and after repairs, these actions alone do not guarantee optimal performance for every application scenario. Given the variability that can occur in different jobs and conditions, regular calibration before each use is the best practice to ensure that the correct amount of pesticide or fertilizer is applied for effective results.