5 June 1998

Breeding cleaner crops is Danes green target

CUTTING sugar beet soil tares to 0.2% would dramatically reduce factory waste disposal problems. That is the long term goal of a cleaner beet project underway at Danisco Sugar, British Sugars Danish equivalent.

Main aim is to allow beet to be processed without pre-treatment at the factory, explains DS environmental manager Bjarne Fallesen. "The idea is very ambitious."

Every year the companys four Danish plants have to treat huge volumes of waste water and get rid of up to 400,000t of soil. With environmental restrictions biting harder pressure is on to find alternative ways of operating.

The part government-funded research, begun four years ago at the DS Development Centre at Nakskov, soon found the ultra-low tare figure could permit waterless processing. Already useful mechanical steps have been taken towards it, but until there is a breeding breakthrough the target remains hard to reach, says Mr Fallesen.

Cleaner loaders were investigated first. In 1992 less than 10% of the Danish crop went through them. Experiments showed soil tares could be cut by half. By 1996, they accounted for about 60% of the crop after an incentive payments scheme was introduced. But even fitted with water spraying attachments, they got nowhere near the 0.2% target, notes Mr Fallesen.

Various harvesters equipped with extra brushes or compressed air cleaning were later found to offer similar improvements, but again failed to meet the ultimate goal. The energy demand of using compressed air is also a barrier, says development manager Lars Jorgensen. "It will do the job but it is too expensive."

Main hope, the researchers believe, is to develop smoother-skinned roots which could be pre-cleaned with water in the field. A key practical difficulty is removing dirt from the grooves in conventional cone-shaped beet.

But breeding such varieties is far from straightforward. Native cylindrical above-ground types and round yellow varieties which can be used in traditional crossings have the desired characteristics but contain little sugar.

A 15-year Dutch programme to produce suitable candidates has so far drawn a blank, says Danisco Seeds Niels Gram. Genetic modification offers some hope, especially if the smoothness gene can be identified. "But if, as I suspect, it involves more than one gene, it is going to become very much more complicated."

&#8226 The first three years work received a 33% grant from the Danish Environment Protection Agency.

[BOX]

Danish beet growers incentive scheme 1997/98.

(Based on average for the season)

Base payment at 83-84% purity.

Max bonus of £1.50/t for 91%.

Penalty of £9.25/t for under 60%.

DRY handling of cleaner beet would undoubtedly bring savings, not least because of landfill taxes on factory soil classified as industrial waste, says British Sugars John Prince. But UK dirt tares much lower than in other EU countries means research into the technique is not a current BS priority. "In the UK the average is 5.5% whereas in Holland and Belgium it is 15-20%.

Mechanical methods such as brushing durinf harvesting and loading help to cut soil intake at the factory, say Bjarne Fallesen (left) and Lars Jorgensen. But ultra-clean beet may only come through breeding.

DRYHANDLING

Dry handling of cleaner beet would undoubtedly bring savings, not least because of landfill taxes on factory soil classified as industrial waste, says British Sugars John Prince. But UK dirt tares much lower than in other EU countries mean research into the technique is not a current BS priority. "In the UK the average is 5.5% but in Holland and Belgium it is 15-20%."

DANISHINCENTIVES

Danish beet growers incentive scheme 1997/98.

(Based on average for the season)

&#8226 Base payment at 83-84% purity.

&#8226 Max bonus of £1.50/t for 91%.

&#8226 Penalty of £9.25/t for under 60%.