NIAB - National Institute of Agricultural Botany
Plant Science Into Practice
Silsoe Spray Applications Unit
(The development and validation of a bystander and resident exposure assessment model)
The NIAB TAG Spray Application Unit at Silsoe is an internationally important facility for the development and measurement of spray application systems, with particular expertise concerning agricultural pesticides.
The unit has a team of specialists with established research experience in spray generation, transport and deposition. This expertise relates to the conducting of field experiments, laboratory work including the use of a specialised wind tunnel, and the development of mathematical models.
Nozzle Performance
The Unit has equipment to:
- Measure droplet size and velocity distributions in a spray with laser-based instruments
- Visualise spray formation processes
- Measure volume distribution patterns
- Sample the whole or part of a spray
Spray Deposits
Visualisation and on-surface measurement
Deposits on plants can be visualised. These images can be used to determine coverage and quantity of spray both directly on the target and in wash off techniques, using:
- coloured tracer dyes
- fluorescent dyes
- active ingredients (if visible)
Quantifying deposits
For tracers:
- Spectrophotometry - for coloured dyes
- Fluorimetry - for fluorescent dyes
- Atomic absorption spectrometry - for metal chelates
For pesticides:
- hplc analysis
- gc analysis
Spray Drift
Field measurements
- Measuring airborne droplet profiles using passive line collectors
- Ground deposits
- Sampling airborne vapour concentration with suction samplers
- Potential deposition on bystanders
- Using tracer dyes or real tank mixes
Wind tunnel studies
- Controlled conditions - wind speed, humidity and crop/surface condition
- Standard tests for LERAP star ratings for nozzles
- Applications to tray grown crops
Mathematical Modelling
Obtaining experimental data, particularly in the field can be time-consuming and costly. Mathematical models can be valuable in mapping from laboratory to the field and in extrapolating field data. We can develop new models as appropriate, and have existing models for:
- Spray drift
- Sprayer logistics
Contact Information
Silsoe Spray Applications Unit
Building 42, Wrest Park,
Silsoe, Bedford, MK45 4HP
Tel: 01525 862995
Fax: 01525 862583
Dr Clare Butler Ellis
01525 862995 x 104
clare.butler-ellis@niab.com
Professor Paul Miller
01525 862995 x 100
paul.miller@niab.com
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