Best Practice Information Sheets (Westcountry Rivers Trust)

Pest management

Best Practice
Information Sheet

Pest management and Pesticide application

IS 2.6.0

Why change?

Arable and livestock pests can reduce productivity and decrease profits. Good pest management and accurate application of the right pesticide at the right time and dose, using properly calibrated machinery, can help you to save money and minimise impact on the environment by:

  • improved crop yields and livestock health
  • reducing the risk of pollution, legal costs and fines
  • reducing the costs of inputs
  • increasing beneficial insect populations
  • increasing wildlife diversity.

Steps to success

  1. Review the current situation by examining pest management on your farm. To begin, consider the area, frequency, timing, rate, method, accuracy and safety of your use of chemical controls. Look at your use of cultural and biological measures for pest management and assess the scope of integrating these with your pesticide use. Review your pest management on a annual basis to help plan strategies for future management.
  2. Identify potential opportunities for improved pest management and application of pesticides. If your chemical inputs are costly and you can identify problems such as pest infestations, reduced productivity and watercourse pollution, you could benefit from a more balanced approach to pest management that combines chemical, cultural and biological controls. Use a BASIS-qualified agronomist for advice on integrated pest management and pesticide recommendations.
  3. Calculate the cost-benefit of these opportunities by considering the cost of improving your management and/or equipment, e.g. buffer zones, low-drift spray nozzles and pheromone traps, versus the savings associated with reduced inputs and more accurate applications.
  4. Develop an action plan for improved management and/or pesticide application on your farm:
    • Integrate chemical control of tests with cultural and biological measures for a cost-effective and long-term approach to pest management (see IS 2.6.1, 2.6.2, 2.6.3 and 2.6.4)
    • only use pesticides when necessary in order to maximise their benefit and minimise costs and risk of environmental damage. Target applications by monitoring pests regularly on a field-by-field basis to identify when pest numbers exceed threshold levels. Use diagnostic techniques to help such as pheromone traps
    • choose pesticides to match the pest and correctly adjust the dose to minimise waste. Aim for pest control as eradication may not be necessary. Try to select pesticides with a minimum potential for environmental damage and spray container washings onto the treated area
    • identify 'no-spray' zones on the ground. You should avoid watercourses, ditches, boreholes, soakaways, wildlife habitats including hedgerows and woodlands, and non-cropped land. Vegetated buffer zones may be required adjacent to watercourses, so follow the advice on the product label
    • use low-drift spray nozzles, and ensure equipment is well maintained and accurately calibrated
    • ensure weather conditions are correct for spraying. Consider wind speed and direction as well as air temperature and humidity. Spray drift increases with wind speed, when temperatures are high and humidity levels are low. Do not apply when the ground is waterlogged, heavily cracked or when rain is forecast
    • for certain pesticides applied using a ground crop sprayer or broadcast air-assisted sprayer, there is a legal obligation to leave an unsprayed buffer zone when spraying next to a watercourse and to record a Local Environmental Risk Assessment for Pesticides if you wish to reduce the buffer zone. Refer to product label for buffer zone requirements (see Defra LERAP booklet PB6533 from Defra publications 08459 556000)
    • Remember to comply with LERAP and Cross Compliance buffer requirements.


Best Farming Practices: Profit from Change

Practical examples

Efficient application saves money

You can save money by:

  • monitoring pest populations on a field-by-field basis and matching pesticide use to the pest problem
  • calibrating your equipment to avoid over-application
  • reducing pesticide drift, e.g. with low-drift spray nozzles.

In a 2005 worked example, the estimated cost of pesticide sprays for a crop of winter wheat is £115/ha/year. If calibration or reduced drift reduced costs by 15%, you could save £17.25/ha annually. With a 20ha crop, this would amount to an annual saving of £345.

To avoid spray drift, use this table as a guide to wind speed. If conditions are unsuitable do not spray.

Description Visible signs Spraying


Smoke rises vertically

Use only 'medium' or 'coarse' spray quality
Light air
Leaves rustle, wind felt on face Ideal spraying conditioners
Gentle breeze
Leaves and twigs in constant motion Increased risk of spray drift - take special care

Moderate breeze


Small branches moved, raises dust or loose paper

Spraying inadvisable


(Adapted from Defra 'Green Code')


Success in Scotland

Work by the Game Conservancy in Scotland has shown the benefit of product choice and timing in pesticide applications to spring and winter cereals.

Beneficial and non-pest insects increase in cereals, whilst grain quality is protected, if broad-spectrum organophosphate insecticides are replaced with pirimicarb or pyrethroids for summer aphid control.

Recent research has also shown that significant reductions in the effective dose rate of chlorpyrifos for leatherjacket control can be achieved by utilising an organosilicone wetter to improve soil coverage.



Disclaimer - Whilst the Westcountry Rivers Trust, its servants and agents (the "Trust") will use its reasonable endeavours to ensure the accuracy of its work, its advice involves matters relating to the natural environment or matters outside its reasonable control. Accordingly, other than personal injury or death arising from its negligence, the Trust will not be liable for any loss or damage howsoever arising directly or indirectly from any act, omission, neglect or default on its part. Funding for updating these information sheets was provided by the Water Quality Division of Defra as part of its England Catchment Sensitive Farming Delivery Initiative. These sheets provide practical information, guidance and recommendations for farmers based on Trust experience. © Westcountry rivers trust, 2007.

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