A LEADING plant pathologist has warned 2004 has been the worst year in the last 20 for wheat disease septoria.

Despite robust triazole fungicide programmes, many commercial crops have high levels of infection in the major yield-producing leaves of the plant, said top ADAS pathologist Bill Clark.

“I knew we were heading for a bad year when I saw signs of septoria in leaf two of treated crops at the end of May,” he said.

“I‘ve never seen anything like it, and it quite alarms me.”

The problem has been largely down to the weather – good growing conditions has brought the latent infection period down to 10-12 days.

“Where control has been poor, it has almost exclusively been a late T1 spray that is to blame,” said Mr Clark.

“Putting on a triazole just a week late – which is fine in most years – meant no control this year.”

More detailed analysis of infection pressure throughout the country can be gleaned from Crop Monitor.

Six of the 15 Crop Monitor trial sites showed very poor or poor control of septoria, despite good triazole programmes.

In only four sites, was control a “good” 80-90%, reported Mr Clark.

“The Cereals 2004 site is a low disease site that received a robust triazole programme, but you don‘t need to be an expert to see that there is very poor control of septoria.”

The site itself forms part of the Central Science Laboratory stand at Cereals, where visitors can find more information about Crop Monitor.