GROWERS IN areas at high risk from fusarium should make the most of T3 sprays to prevent infection, experts have advised.

Unsettled conditions and high humidity, particularly in northern areas, could increase the infection risk and by the time symptoms are visible it is too late, warned the Central Science Laboratory’s Philip Jennings.

Symptoms appear two weeks after flowering and are characterised by a water soaked lesion on the ear, he said. “By the time you’ve noticed these, it’s too late to do anything about it.

“Rain has a role in splashing fusarium around, but there has to be 48 hours of high humidity for infection to take place. Of course, that’s usually the case after rain.”

Eastern England has the highest incidence of Fusarium graminearum, according to CSL monitoring, therefore crops in Norfolk, Lincolnshire and around the Wash are most likely to benefit from a T3 spray, he said.

But most of the UK wheat crop could be susceptible to the disease if conditions are wet and humid at flowering and growers should not rely on resistance rating scores, added Bayer CropScience’s Nigel Godley.

“All varieties on the current HGCA recommended list can be infected. Most are at risk once they start flowering, but varieties which hold on to anthers for longer tend to be susceptible for a longer period of time.”

For best fusarium control, a T3 spray should be applied after full ear emergence as soon as flowering begins, he said. Proline (prothioconazole) can be used from growth stage 55 to GS71, he suggested.