Breakthrough in sugar beet battle against virus yellows

Sugar beet varieties resistant to virus yellows could be available to growers within three years – helping to secure the viability of the crop without neonicotinoid seed treatments.

It follows a five-year pre-breeding project – part-funded by Innovate UK and backed by seed breeders – to accelerate the production of new varieties that provide host protection against the virus yellows complex.

Until this year, neonicotinoid seed treatments protected 99% of UK sugar beet against virus yellows – which can cause yield losses of up to 49%. But neonicotinoids have been banned over concerns they harm pollinators.

In a quest for an alternative approach, the £1.14m project to breed virus-resistant sugar beet varieties began in 2014. It is being led by Adas – supported by the British Beet Research Organisation and seed breeders SesVanderHave and MariboHilleshog.

Promising results

A second year of field trials testing near-market varieties is being hosted by Cambridgeshire farmer Mat Smith at Ramsey Mereside, near Peterborough. BBRO chief scientist Mark Stevens said the trials were yielding promising results.Dr Stevens said: “Virus yellows resistance won’t be available for next year but we are getting incredibly close. If all goes well, and depending on further trials, they could be commercially available to growers within three to five years.”

It is a big challenge – but one that could be hugely beneficial to growers. At least three viruses are involved in the virus yellows complex – making it time-consuming to identify the necessary clusters of genes. In contrast, the sugar beet disease rhizomania involves only one gene.

Breeding programmes

At the same time, scientists warn that the aphids that spread virus yellows could become more prevalent due to milder winters caused by climate change. This year, more aphids were trapped than at any time during the past 30 years.

SesVanderHave UK managing director Ian Munnery said solving the problem of virus yellows was not as simple as breeding-in resistance or relying on a single solution. It was about taking an holistic approach – and bridging the gap between productivity and sustainability.

“We are approaching the final year of this project – and we driven to make sure this works for UK growers,” said Mr Munnery. “We will evaluate the 2019 harvest data and then adapt our breeding programmes to incorporate the lessons we are learning.”