Research by Rothamsted suggests that spraying to control fusarium needs to happen as the ear emerges, rather than the more typical mid-flowering timing used by many growers.

Infection of individual spikelets on an ear was typically indicated by a brown discolouration, said Kim Hammond-Kosack, deputy director of the Rothamsted Centre for Pest and Disease Management.

But the research conducted by Neil Brown as part of his Syngenta-funded PhD had shown that when symptoms were showing on a couple of spikelets that up to a third of the ear was actually fully infected.

“So by the time you spray when you see symptoms it is too late,” Prof Hammond-Kosack said. “It needs to be a preventative spray as the ear is emerging out of the flag leaf – maybe a week to 10 days earlier than most growers spray.”

Further research was under way to identify which fungal genes were responsible for the symptomless infection, with the aim of helping breeders find varieties that could prevent symptomless infection.

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