An expert is warning farmers to watch out for a surge in ramularia leaf spot in spring barley after a harsh dry spell has left crops stressed and vulnerable.
Syngenta specialist Jason Tatnell's warning follows a challenging dry start to the season that he says may increase crop stress and vulnerability to disease.
This year began more favourably than 2024 for spring barley drilling, with early-sown crops benefiting from well-prepared, moist seedbeds and promising yield potential.
However, Mr Tatnell warns growers that the risk of ramularia could rise as the season progresses.
“We know that ramularia starts to show itself in infected plants when crops are subjected to stress factors," he says.
“We’ve already had several of these – including strong sunlight, lack of rain, and potentially reduced uptake of nutrients.
“The arrival of rainfall, while welcome for crop potential, adds a further stress factor – due to sudden nitrogen uptake from the newly-wet soil and a spurt of growth that the crop isn’t prepared for.
"This could further exacerbate ramularia problems. And rain will also increase later-season threats from other diseases, such as rhynchosporium and net blotch."
Mr Tatnell highlights the importance of managing late-season diseases like ramularia, which can affect grain filling and result in reduced yields alongside increased screenings or smaller grain size—factors crucial for markets demanding high grain quality.
“With limited fungicide options available against Ramularia, it’s important to choose treatments carefully,” he advises.
He recommends the twin-pack fungicide Miravis Plus + Era, launched last year, which offers strong control of ramularia alongside effective action against rhynchosporium and net blotch.
“Miravis Plus + Era has repeatedly been shown to be phenomenally strong against Ramularia. So it offers a fantastic all-round fungicide for barley," Mr Tatnell explains.
"Indeed, a Miravis-based treatment has been shown to not only substantially boost yield but also reduce screenings and improve gross margin in malting barley in a Ramularia situation."
If dry conditions continue, Miravis Era helps crops use water more efficiently and keeps leaves green longer to boost yield, he says.
