20 November 1998

Ballerina helps growers in wake of rhizomania

Introducing the rhizomania-

tolerant variety Ballerina to

the rotation is allowing East

Anglian growers to continue

growing sugar beet with

confidence on land adjacent

to infected fields.

Louise Impey reports

WHEN rhizomania was confirmed in just one field at Hall Farm, near Bury St Edmunds in 1994, it had quite an impact on Andrew Longs business.

He closed his sugar beet harvester contracting business and wound up other contract farming activities.

"There were also changes to the rotation in accordance with the containment strategy and strict hygiene precautions were maintained," he says. "The tests showed that it was only a light infection and all the other beet fields proved unaffected."

With 122ha (310 acres) of sugar beet, Mr Long aims to grow the crop on a four-year rotation. His decision to try Ballerina this year was based on its tolerance to rhizomania. "We drilled it on the highest risk field, which neighbour the one with the virus. We felt that we could not jeopardise the business or the rotation any further."

The crop was drilled later than usual, close to the beginning of April, and was irrigated.

"It looks extremely well," says Mr Long. "I have been told that it will yield 30t/acre. Although this is my first experience with the variety, I am not expecting any yield penalty. On this basis, I will grow more of it next year."

Mr Long believes rhizomania is endemic in light soils where it waits for the right conditions and a beet crop to express itself. "Until we have new varieties which are actually resistant, rather than tolerant, then Ballerina is the best choice. It is not the answer to the problem, but it is a good short-term solution," he says.

Infected fields

Another farmer who is using Ballerina to grow sugar beet on land close to infected fields is Peter Wright, of Brettenham Manor, near Thetford in Norfolk.

One of the first farms on which rhizomania was found in 1992, Mr Wright has since had the extra costs and inconvenience of growing beet off farm due to the number of fields found to be infected.

"All the affected fields at Brettenham Manor were found to be very lightly infected, so it was sensible to take measures to minimise the spread of the virus."

His reasons for growing 14ha (35 acres) of Ballerina this year were to restrict the speed of multiplication of the virus within the soil and to be able to continue growing beet in high risk areas.

"Ballerinas ability to slow down the spread of infection is very important for the future of beet growing on this farm," he says. "Otherwise, we will be waiting for fully resistant varieties which have no restrictions on their use, which are still 18 months away."

Mr Wright agrees Ballerina is an interim step. "As legislation stands, Ballerina can only be grown on non-infected fields on farms with a history of rhizomania.

"I hope the containment policy is removed and that we are allowed to grow tolerant varieties even on known infected fields.

"This year, the Ballerina is looking good. But as it suffered from magnesium deficiency earlier in the season, I expect about 15t/acre – not bad on these thin soils." &#42

Andrew Hall (right) of Hall Farm, Fornham St Martins, is hoping for 74t/ha (30t/acre) from this crop of Ballerina, while Peter Wright (left) of Brettenham Manor, near Thetford, is expecting a more modest yield of yield 37t/ha (15t/acre) mainly due to magnesium deficiency. Inset: Good roots from the very light soils at Brettenham Manor.