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Weather at flowering
As ever, the over-riding issue this year will be the weather at flowering. "If conditions are right at flowering, infection is a big risk, almost irrespective of inoculum pressure. So keep an eye on weather forecasts. If you don't get a spray on in time, you'll never get infection out of the ear," he adds.

Mycotoxin producers

With all three pathogens threatening yield and quality, and F. graminearum and F. culmorum producing harmful mycotoxins, the need for robust control is clear he says. Last year's extremely testing conditions showed prothioconazole was again the product of choice, especially where Microdochium was present, since other options do not reduce it," notes Dr Jennings.  

And last season also showed how crucial dose and timing is. He points out that many sprays were too late and even where follow up sprays were used, it would have only controlled later infections.  "Full rate triazoles gave six days of protection, typically three days either side of the application date, which delivered good control if flowering started and finished in that period. But where flowering was extended, follow-up sprays would have been needed to prevent further infection.

"One glimmer of hope around this year's severely delayed crop development could be that crops rush through flowering very quickly. If growth stages are subject to a concertina effect, one well-timed ear spray should suffice. But rates need to be robust, he stresses.

Keep the rates up

Whilst reduced rates may not reduce the period of protection, they certainly reduce effectiveness, Dr Jennings adds. "When it comes to Fusarium I'd say don't play with rates. There's not much point using anything below half rate. Three-quarter rate isn't bad, but full rate is best, and that means a full-rate of triazole. Some formulations contain a reduced ratio of triazole, so even if the full product rate is used, you might still only apply half rate triazole, which really isn't enough," he warns.  

This year, even if flowering is completed quickly, it may not start very early, and maybe not until potentially warmer and more thundery weather in late June or even early July. This could add to the disease pressure and raise issues around rainfastness and spray windows. "It is certainly true that if conditions are good for ear disease, they're invariably bad for spraying," concludes Dr Jennings.