New rules may mean upward-venting pneumatic maize drills may need to be modified

New EU approvals on the continent for maize seed treatments mean that drilling can now only be done by machines that do not vent into the air.

Adrian Cottey, Bayer CropScience campaign manager for seed protection, says that the issue first arose in Germany in spring 2008 when dust caused by incorrectly applied seed treatments was vented upwards by air drills and drifted over neighbouring crops and field margins.

Since then Bayer CropScience has been working in Germany and Eastern Europe to help growers modify their drills, says Mr Cottey. “One of our seed treatment engineers, Martin Oldham, helped to carry out that work and gained useful insights that will help UK contractors and growers.”

The problem applies to pneumatic models, which Bayer says drill the majority of UK maize. “All growers and contractors who use such machines should determine if modifications are necessary. If the drill vents into the air, then it will need modification,” says Mr Oldham.

While it would be unrealistic to modify many drills for this season, he concedes, drill owners should consider doing something as soon as possible.

“As an industry we must not be exhausting any dust into the air where it will contaminate the drill and may affect wildlife,” says Mr Cottey. “If a drill does need modification, first consult the manufacturer to determine if proprietary modifications are available.”

Many manufacturers already offer retrofit kits. “We have already introduced the concept of diverting the air-flow from the vacuum fan exhaust downwards and out through a vent in ground contact with a system called Envirosafe Airkit ED,” says Amazone’s Simon Brown. “This is available for all ED drills as an option and can be retrofitted.”

Graham Owen, product manager for seeding at Kverneland Accord, advises owners to get in touch. “All new drills supplied after November 2009 have been factory fitted with the air deflector modification. We can also supply retrofit kits for in-field machines at a relatively cheap cost. For machines prior to serial number 8619 this is £195, for ones after that number it’s £130.

If modifications are not available from the manufacturer, says Mr Oldham, then the work could be carried out on the farm or by a local engineering workshop.

• There’s a maize drilling stewardship guide on Bayer Cropscience’s website at