The new plans will help raise awareness among farmers and growers of how they might further reduce the impact of pesticides on local water and wildlife and have the support of both water watchdogs and environmental groups.

NFU Vice President Michael Paske welcomed the start of the trials, which form part of the Voluntary Initiative – farming's proactive response to concern over pesticide use which was introduced as an alternative to a pesticides tax.

He said: 'We have worked with industry and environmental groups to produce a model plan that will provide farmers and growers with a valuable opportunity to evaluate their use of pesticides and to demonstrate the environmental steps they are taking.

'By working through the planning process farmers will be able to grade their performance and improve it by adopting simple best-practice guidelines. This will also help achieve cost savings in the short term.' The farming unions will be testing the plan with approximately 25 farmers and growers across the UK over the next three weeks. Comments will also be sought from agronomists.

Michael Paske said: 'These plans have huge potential to demonstrate good practice and to deliver improvements on a broad front in the way we store, handle and apply pesticides.

'The development of these management plans has involved more than a dozen organisations in lengthy but fruitful dialogue. This has helped us to ensure the advice contained in CPMPs is practical and delivered to farmers in the most user-friendly format possible. These trials will help us refine this.' It is hoped that the CPMPs will be available widely to all farmers by early March.