Pesticide Application Methods Flashcards
6 cards from real GROWSAFE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Pesticide Application Methods flashcards as text
What is the most common method of applying liquid agrichemicals to crops in New Zealand?
Answer: Boom spraying
Boom spraying is the most common method for applying liquid agrichemicals to broadacre crops in New Zealand, using a horizontal boom fitted with nozzles to apply product uniformly across a wide area.
What factor most significantly affects spray droplet size in a boom sprayer?
Answer: Nozzle type and operating pressure
Nozzle type and operating pressure are the primary determinants of spray droplet size. Different nozzles produce different droplet spectra, and pressure changes within a nozzle type also affect droplet size.
Why is spray droplet size important when applying agrichemicals?
Answer: Smaller droplets increase drift risk while larger droplets improve coverage of target surfaces in some applications
Droplet size affects both coverage and drift. Fine droplets can drift off-target but provide good coverage on complex surfaces, while coarser droplets reduce drift but may not provide as thorough coverage. The optimal size depends on the product and target.
What is 'calibration' of a spray boom and why is it important?
Answer: The process of confirming that the sprayer delivers the correct volume of product per hectare as specified on the label
Calibration ensures the sprayer applies the correct product rate. Under-application may fail to control the target pest, while over-application wastes product, increases costs, and may leave excessive residues.
What is the purpose of using a 'flat fan' nozzle in broadacre spraying?
Answer: To produce a flat, fan-shaped spray pattern that provides uniform coverage across the boom width
Flat fan nozzles produce a flat, fan-shaped spray pattern that overlaps with adjacent nozzles on the boom to create uniform coverage. They are the most common nozzle type in broadacre spraying.
Under what wind conditions should aerial or boom spraying generally be avoided?
Answer: When wind speed exceeds the product label limit, typically above 15-20 km/h for many products
High wind speeds increase the risk of spray drift onto non-target areas, including neighbouring properties, waterways, and sensitive crops. Label instructions specify maximum wind speed conditions for application.