Growsafe Pesticide Application Methods

Question 1

What is the most common method of applying liquid agrichemicals to crops in New Zealand?

Accepted Answer

Boom spraying

Answer

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.

Question 2

What factor most significantly affects spray droplet size in a boom sprayer?

Accepted Answer

Nozzle type and operating pressure

Answer

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.

Question 3

Why is spray droplet size important when applying agrichemicals?

Accepted Answer

Smaller droplets increase drift risk while larger droplets improve coverage of target surfaces in some applications

Answer

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.

Question 4

What is 'calibration' of a spray boom and why is it important?

Accepted Answer

The process of confirming that the sprayer delivers the correct volume of product per hectare as specified on the label

Answer

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.

Question 5

What is the purpose of using a 'flat fan' nozzle in broadacre spraying?

Accepted Answer

To produce a flat, fan-shaped spray pattern that provides uniform coverage across the boom width

Answer

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.

Growsafe Practice Test

Growsafe Practice Test

Growsafe Pesticide Application Methods