Spray Application – Water Volumes

Many farmers want to improve work rates by spraying with much lower water volumes than are recommended on the label.  There are circumstances where this is not advisable. The information below provides the guidance on this for Dow AgroSciences’ main product range.

Spraying OSR with Falcon
















The following extract conveys CRD’s position on this subject:

Any product can be applied at a lower water volume than that advised on the label provided that the concentration of the product in the water volume to be applied does not exceed the maximum concentration allowed on the product label. For example, if the product label states a maximum product use rate of 1.0 L/ha in a minimum water volume of 200 L/ha, it is also perfectly acceptable for a user to apply 0.5 L/ha of that product in 100 L/ha – in both cases the concentration of the product in water is 0.5%.

Spraying in Wheat

In cases where the concentration of the product in the water is increased beyond the maximum specified on the product label, then you should refer to paragraph 4.6.4 of the Code of Practice for Using Plant Protection Products which states:

“You should not use reduced volumes (i.e. increased concentrations), if the label (or the relevant notice of approval):

  • prohibits reduced volume spraying (for example, if there is a maximum in-use concentration or minimum application volume); or
  • states that PPE must be worn when the product is at the dilution ready for use; or
  • has corrosive, very toxic, toxic, or risk of serious damage to eyes on the product label”

In these situations, you can still lower the water volume if you also reduce the dose of product so that the concentration of the spray solution is no greater than the maximum recommended on the product label as outlined earlier. However you may apply at reduced volume (i.e. increased concentration) if an appropriate risk assessment, often done by the manufacturer, shows that this is just as safe.

Some labels state that PPE should be worn when handling contaminated surfaces. The need for PPE to be worn is assessed separately for measuring out the product into the application equipment and for the application stages. The application stages include handling booms, changing nozzles and clearing up after use which will involve contact with surfaces contaminated by diluted product. Therefore, because PPE is required to protect against exposure to the diluted product, you should not apply at reduced volume (i.e. increased concentration) unless the manufacturer has done a risk assessment that shows it is just as safe. Dow AgroSciences have carried out risk assessments for a number of products used on cereals, oilseed rape and grassland at lower water volumes than label and the results of this are detailed below.

Further details on water volumes may be found on CRD’s website at: http://www.pesticides.gov.uk/guidance/industries/pesticides/