4 June 1999

Use tested types for most of the mix

Sugar beet remains one of

the most profitable crops for

many arable farms. This

special focus homes in on

several topics designed to

ensure it stays that way,

starting with Edward Longs

critical look at variety

choice for 2000. Edited by

Andrew Blake

PICK tried-and-tested varieties for the bulk of your acreage, but grow some newer ones on a small scale to gain experience of possible future bankers.

That is the advice of NIABs Simon Kerr who warns against using new high yielders for the lions share of the 2000 crop.

"It is essential that a relatively high proportion of fully recommended varieties are chosen," he says. "Thats because they will have been tested over at least three years grown from commercial seed. "Provisionally recommended types normally secure their place on the list having been trialed using breeders seed. It is not usually until years 3 or 4 that the switch to commercial stocks is made.

There are five fully recommended varieties for 2000 – Alexa, Jackpot, Roberta, Triumph and Zulu. They are backed by 16 provisional recommendations including three new ones, Ariana, Stallion and Wildcat, and three rhizomania resistors. Low bolting Celt is specially recommended for sowing early.

A varietys ability to withstand bolting and emerge well is important, particularly on exposed farms and where growers with large acreages need to sow early.

All varieties will bolt if exposed to 40 days with a maximum temperature of 12C (54F) between Mar 1 and the end of May. Records show an average of 30 such cold days in March, 15 in April, and five in May.

"For the past few seasons we have recorded temperatures at our 14 trial sites round the country to help determine the critical day degree limit for each variety. Until we know this growers should play safe."

Alexa and Jackpot should not be used for first drillings as they tend to bolt more than others. The same is true of provisionally recommended Camilla and Madrid.

Varieties with good establishment include Roberta, Zulu, Madison, Madrid, Oberon, Swift, and Wildcat.

Zulu, which had been losing market share, performed exceptionally well last year. In NIAB trials it had the highest sugar yield of all, producing a growers income of 103.2 compared with the next best, Wildcat, on 101.9.

Third with 101.2 was Ariana, with Roberta fourth on 100.8.

"Triumph did not do quite as well but still gave a consistent performance to earn its place on the new list.

"Roberta, which did well across Europe, is a reliable cropper and well worth its old favourite status. When first listed it was not a particularly high flier with a growers income of 105, the same as Saxon which has since disappeared."

Although Mr Kerr is keen for the bulk of the area to be drilled with fully recommended varieties, no single one should dominate, he advises. &#42

Fully recommended varieties should occupy most of a farms beet area, advises NIABs Simon Kerr.

Age concern

The oldest variety on the latest NIAB list is Celt, dating back to 1990. Triumph and Zulu were first recommended in 1992, Roberta a year later. Jackpot appeared in 1995 and Alexa gained NIABs seal of approval in 1996.

Few varieties are as durable as Celt, Triumph, Zulu and Roberta. By the time it was dropped Saxon had notched up nine years, and Amethyst, which arrived in 1984, made its 10th anniversary.

Rhizo resisters join special use list

Two of the new provisionally recommended varieties for 2000, rhizomania resisters Rebecca and Rosana, join Ballerina on the list for special use. All three have been trialed on infected land in Holland and non-infected land this side of the North Sea.

This year, for the first time, resistant types have been drilled on moderately infected land on three farms in Suffolk and Norfolk in tests alongside susceptible varieties.

"Rhizomania has become so widespread in Holland that it is no longer possible to include susceptible varieties for worthwhile comparison. Our trials will be a real test of how they all perform under UK conditions," says Mr Kerr.

Climbers (% of crop)

Jackpot Roberta

1996 3 3

1997 8 6

1998 8 9

1999 15 16

Sliders (% of crop)

Zulu Madison Oberon

1996 27 – –

1997 24 25 –

1998 12 33 13

1999 7 17 11

Ups and downs

Madison was favourite variety last season with 33% of the UK crop. Oberon was second most widely grown with 13% followed by Zulu with 12%.

"Madison was popular right from the start," says British Sugars seeds specialist, John Prince. "In 1997, its first commercial year, it took a 25% share. This was because of its high sugar yield and growers income plus its good emergence and bolting. This year it accounts for about 17%.

"Zulu and Saxon followed a similar pattern. Saxon had over 30% at its peak four years ago but has since disappeared. Zulu is still around with 7% compared with 12% in 1998, 24% in 1997 and 27% in its debut year 1996.

Celts popularity has declined sharply. In 1994 it was used for 23% of the national crop. Now it accounts for less than 1%."

Roberta is taking time to build a market. In its first year, 1994, it took 4%. This increased only slightly to 6% by 1997 and to 9% last year. But it accounts for 16% of the current crop.

Jackpot has also taken time to find its feet. In its first year it took 3%. It jumped to 8% last year and has almost doubled to 15% this season.