12 March 1999

Resistant varieties of sugar beet key to winning rhizo war

By Bill Hollowell

RHIZOMANIA controls have served the sugar beet industry well. But it is resistant varieties that will ultimately conquer the disease, say industry experts.

The containment policy has clearly worked, slowing the spread of the disease, rhizo specialist Mike Asher told a recent meeting at IACR-Brooms Barn.

But, without prejudging the current policy review, the problem will eventually be solved by using resistant varieties within the coming few years, he said.

Growers will have three such varieties next year – Ballerina, Rebecca and Rosanna. But current rules mean they can only be grown on uninfected fields on farms which already have the disease.

Currently 4000ha (10,000 acres) on 97 farms – all but one in East Anglia – are infected. Computer models predict a rise to 45,000ha (125,000 acres) in 15-20 years.

In Holland, where the disease is now widespread, about half the crop will be in resistant varieties this year, said Jan Wevers of the Dutch Sugar Beet Research Institute.

Growers in badly infested areas stand to lose no more than 5% of income and about 4% sugar yield by using such varieties, he said. "They regard that as their insurance premium and a small price to pay when the alternative might be to stop growing sugar beet."

The challenge now is to identify varieties which are as effective in the UK as in continental Europe. Initial trials suggest the current options are not, Dr Asher noted.

British Sugars seed manager, John Prince agreed. "We need to continue the trials programme to determine the best way forward." &#42