The potential “flying start” benefits of a new treatment for oilseed rape have encouraged a UK seed supplier to send material abroad to have the dressing applied.

Thiamethoxam insecticide, recently approved for use on sugar beet in the UK is not yet available here for use on oilseed rape.

But its effect on the crop is such that United Oilseeds has exported 20t of the variety NK Grace to Germany to be treated there and re-imported.

“NK Grace plus TMX has a reputation for getting going when conditions get a little tricky,” says the firm’s Richard Elsdon. “That’s because the treatment encourages root development.”

Exporting seed and re-importing it treated with a pesticide not yet approved in the UK is perfectly legal, says Charles Paice for thiamethoxam manufacturer Syngenta.

“It’s legitimate under the registration rules, but it doesn’t have our support,” he stresses.

However, the TMX product Cruiser OSR (thiamethoxam + fludioxonil + metalaxyl) has been approved on oilseed rape in Germany for about 18 months.

“Our trials would suggest that it helps root development especially in dry conditions and it does offer superior flea beetle control.”

A seed treated with a pesticide does not fall under the control of the UK’s Pesticides Safety Directorate, confirms spokesman Mick Oliver.

“Pesticide laws control treating the seed with the pesticide in the UK but not the subsequent use of the treated seed. In this case the firm is not importing a pesticide but a seed. Seeds are controlled by other legislation.”

He stresses that there is a voluntary agreement between PSD and industry to ensure the safe use of treated seed.

The label should include all appropriate directions and precautions for safe use, and he advises anyone intending to import treated seed to make sure they understand and follow this agreement.

The export/import exercise is not without precedent, according to Nigel Padbury of Syngenta NK Seeds’ which bred NK Grace.

No seed treatments for maize nor many vegetables are approved in the UK, he points out. “So 100% of the treated maize seed sown here is imported.”

“What we want to do is to work with United Oilseeds as a principal supplier to give growers the chance to take, say a bag, of the re-imported seed to sow alongside their usual treatment to see how it compares. We want to get it into as many hands as a ‘look-see’ exercise as possible.”

The 20t should sow about 4000ha (10,000 acres) – a relatively small fraction of the UK crop, he adds.