Glossary of Terms

Application technique

The methods of application are broadly grouped under 'Field Sprayer' - including mechanically-drawn boom sprayers (e.g., tractor, truck or all-terrain vehicle mounted boom sprayers and self-propelled high-clearance sprayers); Chemigation Sprayer - all pressurized sprinkler irrigation delivery systems used for pesticide application (e.g., travelling guns, center pivots and overhead boom systems); Airblast Sprayer - includes all air-assisted fan sprayers used in orchard, vineyard and field crops (e.g., axial fan, cannon, and tower sprayers); and Aerial Sprayer - refers to either fixed-wing (airplane) or rotary-wing (helicopter) delivery systems.

Boom height (m)

The height of the boom above the crop or bare ground (for pre-emergent applications) is required for the buffer zone calculator. Field sprayer boom heights of greater than 0.6 m above the crop have a greater drift potential and are considered "high boom sprayers" in the buffer zone calculator.Consult the nozzle manufacturer's guidance for the minimum effective boom height above your target.

Buffer Zone

A spray buffer zone is defined as the distance between the point of direct pesticide application and the nearest downwind boundary of a sensitive habitat, unless otherwise specified on a product label.  It mitigates non-target deposition of spray.

Land description

The municipal lot number, parcel number, or other identifying description that clearly indicates which section of property is being sprayed during the application event.

Nozzle

The manufacturer's trade name for the nozzle used (e.g., Turbo TeeJet Induction 110 025, HARDI INJET 04 air induction 120° flat fan nozzle, Lechler IDK nozzle IDK 120-02, etc.).

Nozzle deflection (°)

The angle, in degrees, from horizontal that a spray nozzle mounted on the spray boom is directed downwards toward the crop. For example, a 30° angle nozzle on an aircraft will discharge spray backwards into the airstream, pointing 30° downward from a horizontal plane along the spray boom. The greater the angle of deflection into the wind, the higher the amount of air-shear that will occur, creating a greater number of smaller droplets with a higher drift potential.

Nozzle flow rate (L/minute)

Nozzle flow rate used during application.

Product application rate

The rate of product applied to the crop using properly calibrated spray equipment, in L/ha for liquid formulations, or g/ha for dry formulations.

Product label

The product label that is approved as part of the registration process contains the conditions of registration that, along with the PCP Act and Regulations, govern the use of the product. In effect, the label is a legislative document. Use of a product in a manner that is inconsistent with the directions or limitations on the label is prohibited. Any control product offered for sale in Canada must bear the approved label.

Registration No.

The unique number assigned to each registered pest control product by the PMRA. The four or five digit number is found on the front page of the product label.

Relative humidity

The ratio of the amount of water vapour in the air at a specific temperature to the maximum amount that the air could hold at that temperature, expressed as a percentage. Relative humidity (RH) at the time of application is required for aerial applications, as it affects spray drift potential. Pesticide carrier droplets (water) evaporate faster under low RH, increasing the distance they can travel before falling to the ground.

Spray Drift

Particle (droplet) spray drift is defined as the wind-induced movement of spray particles (droplets) away from the spray swath during application. This definition does not include vapour drift or other mechanisms of off-target deposition such as run-off. For the purposes of this document, the term 'spray drift' refers only to particle drift.

Spray Quality (ASAE)

The ASAE Spray Quality Category system is based on the American Society of Agricultural Engineers S572 Standard. The system classifies spray from nozzles in categories according to the Volume Mean Diameter (VMD) of the droplets produced. Many nozzle manufacturers have instituted a colour-coding system which matches nozzle type with its operational ASAE Spray Quality Category. The Buffer Zone Calculator allows for drift comparisons between ASAE Spray Quality Categories of Fine (VMD = 100 - 175 µm; nozzle colour orange), Medium (VMD = 175 - 250 µm; nozzle colour yellow) and Coarse (VMD = 250 - 375 µm; nozzle colour blue).

Spray Quality on Label

The minimum ASAE Spray Quality Category shown on the Canadian product label, found under the "DIRECTIONS FOR USE" section.

Spray Quality at Application

The ASAE Spray Quality Category that the applicator wishes to use at the time of spraying.

Temperature (°C)

For aerial applications, the air temperature is required from the site of application or at the airfield (if located nearby to crop) at the time of application. The higher the air temperature, the faster the spray droplet will evaporate before reaching the ground, thereby increasing its drift potential.

Wind direction

The direction the prevailing winds are blowing from. For example, a westerly wind is blowing from the west to the east.

Wind speed

For the buffer zone calculator, wind speed is entered in km/h. Wind speed should be measured at a height of at least 1.5 m above ground. For For airblast spraying, measure upwind of the orchard. A wind vane on-site, or a handheld anemometer will provide the most accurate readings. Prior to spraying, winds should be monitored over a 2-3 minute span, recording in particular the maximum sustained wind speed and average wind direction during that period.