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Silsoe Spray Applications Unit

Technical Services

Silsoe Spray Applications Unit undertakes a range of testing for commercial customers. These include both standard tests to recognised protocols or standards, and bespoke investigations to address specific questions. We have UKAS accreditation to meet BS EN ISO 17025:2005 for some procedures and for our most commonly used analytical techniques.

We also undertake a wide range of research projects

Nozzle Performance

Nozzle performance                    Nozzle performance

The Unit has equipment and expertise to:

  • Measure droplet size and velocity distributions in a spray, airborne droplet concentrations and fluxes with laser-based instruments – Oxford Lasers Visisizer and Malvern SprayTec
  • Visualise spray formation processes
  • Undertake spray classification according to BCPC or ASABE protocols
  • Measurement of nozzle flow rates, spray fan angle, and spray distribution patterns


Spray Deposits

Spray DepositsDeposits on plants and other surfaces can be quantified, using a range of tracer chemicals:

  • coloured tracer dyes, using spectrophotometry
  • fluorescent dyes, using fluorimetry
  • active ingredients, using hplc in-house, or working with specialist analytical laboratories for more complex techniques


Spray DepositsImages of target surfaces can be obtained using photography and image analysis to determine the area covered by spray

The wind tunnel can be used to make controlled applications to tray-grown crops under field conditions, allowing determination of

  • Quantity deposited on the plant
  • uptake of active ingredient
  • rainfastness of plant protection products


Spray Drift

Spray Drift         Spray Drift

Field measurements

  • Measuring airborne droplets using passive line collectors
  • Ground deposits
  • Exposure of non-target species, including bystanders
  • Sampling airborne vapour or droplet concentration with suction samplers
  • Potential deposition on a range of targets, including plants
  • Using tracer dyes or real tank mixes
  • Measurement of meteorological conditions


Wind tunnel studies

  • Wind Tunnel StudiesControlled environmental conditions - wind speed, humidity and crop/surface condition
  • Standard tests for LERAP star ratings for nozzles
  • Drift measurements according to other wind tunnel protocols (such as DIX)


Other tests

Other TestsWe can offer a range of other tests associated with pesticide application and sprayer operation, including container pouring and cleaning, induction hopper performance.

Training courses

We also undertake bespoke training courses, either at our Silsoe site, where demonstrations of the wind tunnel and other equipment can be included, or at a site to suit the customer.

Typical course content would include spray drift, nozzle choice, optimising application for maximising pesticide efficacy, effect of spray liquid on spray behaviour, and can be used to gain Basis or NRoSO points.

Please contact us for further information about the technical services we can offer.