Soils in many parts of the country are at field capacity with drains beginning to run. This means any additional rainfall may result in recently applied pesticides moving through the soil profile to field drains and water courses.
VI pilot catchment manager Nick Humphrey said: "Where soils are at field capacity, farmers [and growers] who want to apply sprays should be paying special attention to weather forecasts."
"If heavy rainfall is likely in the 48 hours after application then the risk of pesticides being washed into drains and water courses is high. Similarly, if drains are actually running, spraying should be postponed."
In the East of England, many fields still have deep cracking from the summer drought. Where these conditions exist, the VI advice is to delay spraying until these cracks close up.