WHEAT GROWERS have been warned to be vigilant against disease as most crops in the UK are now at flag leaf.

The top leaves may look clean, according to reports on Crop Monitor, but disease pressure is very high and growers must not be lulled into a sense of false security.

The presence of septoria symptoms on leaves 3 and 4 is a good indicator of risk of the disease, according to ADAS pathologist Bill Clarke in the latest Crop Monitor national report .

“High-risk septoria varieties should be targeted for urgent treatment,” he advised.

Yellow rust has also been found in a small number of crops in the east, he reported.

“These outbreaks are confined to varieties which are susceptible to the Brigadier race of yellow rust.

“Most T1 and T2 sprays would contain sufficient triazole to give adequate control of yellow rust.”

But other experts have seen neither sight nor sign of the disease, despite warnings that pressure could be growing.

“We‘ve not getting any reports of yellow rust,” said UAP technical director Chris Bean.

“Even in untreated trials there doesn‘t seem to be a single pustule.”

Septoria is the major threat, he stresses, but timely T1 treatments should have kept its progress in check.

“Those crops that received a T0 treatment are cleaner, especially the higher risk varieties.

“The concern is that in various parts of the country the T1 was delayed and the potential for disease is that much greater.

“So if you haven‘t got the T2 on yet, get the sprayer out now.”

Mildew has been coming in fairly widely across crops, and levels are variable.

“The mildew pressure in crops we‘ve seen doesn‘t necessarily reflect HGCA Recommended List ratings,” added Mr Bean.

The Norfolk and Cambridgeshire  Association of Independent Crop Consultants report on Crop Monitor reflect this finding.

The full national report and more regional round-ups can be found on the Crop Monitor site.

Crop Monitor is a new, free service that uses live data from trial sites across the UK along with historical data to give growers an accurate picture of disease development in wheat and oilseed rape .

Funded by the Department for the Environment, Food and Rural Affairs and run by Central Science Laboratory, weekly updates are provided by ADAS pathologists and AICC agronomists.

The Crop Monitor website allows users to view data in graphs by region, variety, cultivar, leaf number or a combination of their choice.

The site also provides access to historical data from DEFRA-funded research and showcases new research developments.