Autumn-sown sugar beet crops could be included in UK rotations in the future, but only through the development of bolting-resistant varieties using genetic engineering.
A recent British Sugar and Farmers Weekly study tour to Spain visited autumn-sown beet situated in the south of the country, and despite the milder climate being less conducive to bolting, it begs the question: could it work in the UK?
Spain currently grows in excess of 30,000ha of sugar beet, of which about 7,600ha is established in the autumn in the southern region of Andalucia.
"One of the advantages of winter beet in the south is the lower water necessity compared with spring beet, due to the use of winter rains," says Rodrigo Morillo-Velarde, director at AIMCRA.
"Drilling in the autumn period also ensures that the maximum solar radiation coincides with maximum leaf area index, so the crop has its highest production potential.
"We do have problems with randomness of pests and diseases due to the climatic variations, high competition from weeds that germinate throughout the autumn, winter and spring and also some bolting," he says.
Despite bolting in the unlikely event of extremely cold weather, it is something that can be controlled by using conventionally-bred varieties with bolting resistance, adds Mr Morillo-Velarde.
It is the use of the water and sunlight during the months of April, May and June with a large canopy that would appeal to UK growers, which would subsequently increase yield potential.
"It would be such a huge genetic move for the UK, as you are moving the drilling period ahead of the vernalisation conditions during the winter, so realistically, it is something that only GM technology could facilitate," says Patrick Jarvis, best practice agriculture manager with ABSugar.
"What comes with that is all the usual problems associated with genetic engineering, such as government and public opinion. British Sugar would only use the technology if it received the approval from its customers.
"There is great potential for yield benefits, which in turn increases gross margins and reduces costs, but it is something that is not going to happen immediately," adds Mr Jarvis.
Winter beet in the UK is not a new idea, with trials taking place in previous years being extremely unsuccessful due to the whole crop bolting. There are also issues with frost tolerance, which is shown by the severe losses seen during the 2010/11 campaign.
"It would be a case of combining the genetics that prevent bolting and also provide winter hardiness, and with this you could see the possibility of yields up to 25% higher than we have now," says Richard Powell, sugar beet portfolio manager for Syngenta in the UK.
"We have the ability to prevent plants from bolting during the winter, but it is a very complicated process and is a long way from commercialisation," adds Mr Powell.
The switch to autumn-sown sugar beet, despite the yield benefits, would provide new challenges when considering weed, pest and disease pressures.
With the potential that there would be crops in the ground waiting to be harvested while next year's crop is being established, the perfect "green bridge" would be created for the transmission of pests and diseases.
"You would certainly see an increase in beet yellows virus, with aphids keeping the disease going across that green bridge, and it can result in up to 50% yield loss from reduced root weight and sugar content," says Mark Stevens, head of site at Rothamsted Research - Brooms Barn.
"Downy mildew, which is not a major issue in spring-sown crops, could also become more prevalent with the introduction of winter beet, which also results in significant losses and the loss of the growing point.
"If you can get over these issues there is definitely potential to increase yields and maximise factory output," says Dr Stevens.
British Sugar is carrying out research into the management issues surrounding autumn-sown sugar beet, with trials starting this year. It will look at the establishment issues, weed control and pest and disease pressures.
"We will also be looking at how big the beet needs to be to get through the winter," says Colin Walters, agricultural development manager at British Sugar.
"In the first year I think we will produce many more questions than answers, but we need to find out the challenges that we could face and what we have in the armory to deal with them.
"Winter beet is not a new idea, but it could be a viable option for the UK, although not for a number of years yet. What this research will ensure is that we understand how to manage the crop when it does arrive in the future," says Mr Walters.
In addition to the different agronomic factors winter beet crops would bring, it would have to be considered how it would fit into an already congested work schedule for growers during the autumn.
"I wouldn't really want to be doing any more drilling in the autumn, however, it could be considered if we were to invest in strip tillage to conserve moisture," says Mark Means, a Norfolk grower and contractor who manages about 200ha sugar beet.
"Moisture conservation would be a key issue, as it's not usually something you would have to worry about during the spring when you are waiting for seed-beds to dry sufficiently enough to travel.
"The extra investment in the machinery to use a strip tillage system could be used for both oilseed rape and sugar beet, which could make it a worthwhile investment," explains Mr Means.
The spring sugar beet crop allows good blackgrass control, and Mr Means is also concerned about the loss of this useful tool against the most significant arable weed.
"In the autumn you could sometimes be struggling in either extremely dry conditions, or indeed wet, which would not only hinder establishment but also affect efficacy of herbicide applications," says Mr Means.
"I would much rather focus on producing varieties suited to drilling slightly earlier in the spring to maintain that blackgrass control."
This sentiment is shared by Ian Mullery, general manager at SESVandeHave, who sees much more value in investing in maximising the spring-sown crop.
"Current genetics can achieve up to 130t/ha in spring-sown varieties, so it would probably be more important to focus on water and nitrogen efficiency to improve what we have.
"The economics would also have to be questioned - how much more can be achieved from growing winter beet and at what cost?
"It may well be possible, but is it desirable, because currently spring sugar beet fits nicely in the growers' workload," he says.
• Winners of the British Sugar and Farmers Weekly Beet the Best competition won an all-expenses-paid study tour to Spain, looking at sugar beet crops in the northern and southern regions of the country.
• Look out for the Beet the Best competition at this year's Cereals event on 13-14 June at Boothby Graffoe, Lincolnshire.
• Beet yellows virus was spotted in Spanish sugar beet trial crops this season. See a video of Mark Stevens giving more details of this disease