USING THE right product at the right time is only way to tackle orange blossom midge, cereal growers have been warned.

UK wheat producers spent more than £2m trying to control the pest last season with only limited success, Dow AgroSciences‘ David Roberts told an HGCA conference.

More than 0.5m ha (1.23m acres) were treated against midge in summer 2004 – a significant factor in the 36% rise in overall cereal insecticide use over the previous year.

Only 15% of the area however was treated with chlorpyrifos, the sole active ingredient approved for use, and the only one effectively controlling both larvae and adults for more than a week, Mr Roberts noted.

For financial and environmental reasons, growers should apply products only when they are really needed and use them correctly, he advised.

To justify using Dursban WG (chlorpyrifos) several strict conditions must be met.

Sprays should be used only when the crop is at the susceptible growth stage, when adult midges are present, and when the thresholds of one midge per six ears (for seed/milling crops), or one per three ears (for feed crops) are met.

Applications should also leave a 12m strip of headland unsprayed.

“Unless all these criteria are met, we do not advise using Dursban WG,” said Mr Roberts.

The unsprayed headland strip ensures that a reservoir of beneficial insects remains around the field to recolonise it after treatment, he explained.

“Some farmers have turned to alternatives to save money, but choosing a product that does not work is just false economy.”