‘No room’ for complacency with rust control

WELL-TIMED spring fungicides are better than autumn seed treatments when creating a solid foundation for season-long disease control in winter wheat, says an agronomist.

After a relatively benign season, winter wheat variety choice ahead of drilling this autumn is likely to follow a similar pattern to the current season, with growers relying on key varieties susceptible to yellow rust.

“For the first time in a few years, there doesn’t seem to be any outstanding new varieties to opt for to take things forward,” said Andrew Wells.

But growers couldn’t afford to be complacent after a relatively benign season.

The main rust triazoles of cyproconazole and tebuconazole played a key role at the T0 timing and formed the foundations for T1, setting up the disease control programme for the season, said Mr Wells.

“Where people used either cyproconazole or tebuconazole for yellow rust at T0, it worked well this season,” he claimed. “No, it wasn’t a high disease pressure year, but the treatment wasn’t expensive.”

Growers were better off targeting problems like rust at T0 with a reliable rust-acting triazole like tebuconazole, rather than going for a more expensive autumn seed treatment with rust activity.

This was especially so during more typical seasons weather-wise when leaves that contributed most to the final grain yield were emerging and T1 or T2 spray applications were delayed.

“It’s asking a lot of a triazole seed treatment to provide protection of a plant 4-5 months after drilling, and, on a cost-per-hectare basis, there’s better value to be had by spraying early in the spring.”

Most people could get a T0 fungicide on their crop should question whether they need a rust active seed treatment,” Mr Wells added.