Spray Application

Plant Protectants are used in the vegetable industry to control pests, diseases and weeds. The majority of these products are applied in the form of droplets produced from different types of nozzles mounted on spray booms. To maximise spray efficiency, droplets must be uniformly distributed on the target surface with minimum loss (usually caused by drift, evaporation and run-off).

Poor spray application techniques waste chemicals, reduce control of pests and result in loss of yield and quality. This ultimately leads to lower returns for the grower.

Droplets are very small and usually measured in microns (μm), with one micron equalling one thousanth of a millimeter. When operating at any given pressure, hydraulic nozzles produce a range of droplet sizes. There is an important relationship between droplet size, volume and the number of droplets that can be produced from a fixed volume of spray application. As the size of droplets reduces, the number produced from the same volume of spray increases.

To achieve the best possible spray coverage you need to consider the following:

• Accurate pest and disease identification
  
  
• Suitable droplet size and water volume
  
  
• Application under the appropriate environmental conditions
  
  
• Using clean water of the correct pH
  
  
• Correctly calibrated and maintained spraying equipment