Growsafe Spray Application Techniques

Question 1

What is the recommended maximum wind speed for ground-based agrichemical spraying in New Zealand?

Accepted Answer

Up to 15 km/h, depending on the product and application method

Answer

No limit if using low-drift nozzles

Answer

Up to 30 km/h with proper equipment

Answer

Spraying is only restricted in completely calm conditions

Question 2

What is calibration of spray equipment designed to ensure?

Accepted Answer

The correct volume of spray mixture is applied per hectare

Answer

The spray pump pressure is at maximum output

Answer

The tractor travels at the fastest possible speed

Answer

The chemical concentrate is used at full strength

Question 3

In NZ, what is an inversion layer and why is it dangerous for agrichemical spraying?

Accepted Answer

A weather condition where cool air is trapped under warm air, causing spray to hang and drift unpredictably

Answer

A soil layer that prevents chemical from reaching plant roots

Answer

A type of spray nozzle pattern that inverts the spray cone

Answer

A chemical reaction that inverts the pH of the spray solution

Question 4

What nozzle type produces the coarsest droplets to reduce spray drift in NZ conditions?

Accepted Answer

Air induction (AI) or low-drift nozzles

Answer

Hollow cone nozzles

Answer

Fine mist nozzles

Answer

Fan jet nozzles at high pressure

Question 5

What is the purpose of adding a surfactant or wetting agent to an agrichemical spray mix?

Accepted Answer

To improve spray coverage and adhesion on plant surfaces

Answer

To make the chemical less toxic to the operator

Answer

To increase the rate of chemical breakdown in sunlight

Answer

To change the colour of the spray for visibility

Question 6

Under NZ regulations, what records must be kept when applying agrichemicals commercially?

Accepted Answer

Product name, rate, area treated, date, time, weather conditions, and operator details

Answer

Only the product name and date of application

Answer

Records are only required for aerial application

Answer

No records are legally required for ground spraying