5 June 1998

Steady strides to a better

choice of varieties

Last season the UKs 9000

sugar beet growers

produced a record 1.59m

tonnes of sugar. In this

special focus we examine

key areas that should help

continue the success story

starting with variety choice.

Edited by Andrew Blake

PROGRESS in sugar beet breeding is all too easily over-looked in the annual task of choosing varieties. But good strides have been made, says NIABs Simon Kerr.

A decade ago Amethyst was top of the Recommended List. Madison, currently a popular provisionally-recommended variety from the same breeder, offers a growers income 7% higher, says Mr Kerr. "Thats not bad going." Another positive move has been the slide in juice impurities. Though not yet rewarded in growing contracts, it makes processing easier.

Madisons performance last year was quite poor, but that merely highlights unusual growing conditions and shows how seasonal effects have a strong effect on the ratings, he explains.

That said, and with no premature knowledge of 1999 weather, how can growers select the best names for their own circumstances?

Those with small areas should to stick to just two, one from the fully recommended quartet with perhaps another from the 11 provisionally recommended, suggests Mr Kerr.

Larger contracts may merit a wider spread. "It is prudent to take at least two but you really dont need more than four."

Sugar yield and hence growers income, derived from the combination of root yield and sugar content, is the key to selection.

"Last year was strange because we had some very high root yields but sugar contents remained relatively high, so high root yield types like Roberta and Jackpot did especially well." By contrast high sugar content types like Madison and Madrid did poorly, because their relatively low root yield was unable to compensate. The former is thought to account for over a quarter of the 1998 area. "But growers should not be too alarmed by its drop in performance," comments Mr Kerr.

Roberta has done very well in the past three years. "It has also done so on the continent which is unusual." Jackpot, Triumph and Zulu have similar sugar contents though Zulu has a slight edge.

Fenland growers especially should continue to use high sugar content types, advises Mr Kerr. Highest rated is Nicola on 18.8%, followed by Madrid (18.5%) and Clarissa and Madison (both 18.4%). Least sweet, bar Ballerina, is Oberon on 17.8%.

Bolting resistance is acceptable in most varieties. But Jackpot, along with Alexa, Camilla, Madrid and rhizomania-resistant Ballerina are best avoided if sowing before mid March, he says. For very early sowing there is probably only one choice, Celt, which stays on the list for that specific reason, its growers income being the lowest of all, bar Ballerina.

Establishment ratings have improved greatly in 10 years, but it is worth bearing in mind that three of the lists five newcomers, Anthem, Chorus and particularly Clarissa, have rather low scores, says Mr Kerr. However Choruss growers income is the highest on the list.

Swift, another 1999 introduction, comes second in the growers income stakes. "It has a high sugar content and good establishment. It looks a good variety."

Duke, the fifth addition, is unusual in having a very small top and low crown height. "It wouldnt be suitable for the few growers with belt lifters."

Up for consideration to fully recommended status next year, along with Madison, is Alexa, he notes. "It has maintained its performance so it is quite a strong candidate."

Changes in MAFF rules mean Ballerina may be grown on rhizo-infected farms but not infected fields from this year, he notes. Although least rewarding in terms of growers income in the absence of the disease it should help minimise its spread, says Mr Kerr.

{BOX}

NIAB 1999 List.

GI rating*

Fully recommended:

Jackpot (Del) 100.6

Roberta (ESB) 101.6

Triumph (Del 99.5

Zulu (Nov) 98.2

Special recommendation:

Celt (Nov) 96.3

Provisionally recommended:

Alexa (ESB) 100.8

Anthem (Nick) 101.2

Camilla (ESB) 98.8

Chorus (Nick) 102.6

Clarissa (ESB) 100.9

Duke (Del) 101.4

Madison (Dan) 99.3

Madrid (Dan) 99.5

Nicola (ESB) 100.8

Oberon (Nov) 100.5

Swift (Adv) 101.8

Provisionally recommended for

Special use:

Ballerina (ESB) 95.5

Breeder/UK agent key: Adv = Advanta, Dan = Danisco, Del = Delitzch, ESB = English Sugar Beet, Nick = Nickerson, Nov = Novartis.

* Differences of less than 3% should be treated with reserve, says NIAB.

Steady breeding headway offers growers a wide choice of useful varieties.

Large topped varieties like Oberon can be useful for growers with belt lifters.

CONTENTS

&#8226 Varieties & seed page

treatments 72/73

&#8226 Rhizomania & transgenic promise 74

&#8226 Powdery mildew and

weed beet 75

&#8226 Transport debate 76

&#8226 Cost cutting scope 77

&#8226 Tramlining attractions 78

&#8226 Clean beet progress 79