Steady breeding progress brings fast list turnover
Steady breeding progress brings fast list turnover
It is only in retrospect that the true value of sugar beet breeding
emerges, as Andrew Blake discovers from last years FW/Du
Pont Sugar Beet Grower of the Year and NIABs Simon Kerr
BREEDERS efforts have transformed sugar beet production in the past decade allowing growers to produce more sugar from less land.
"At first glance year-to-year improvements in varieties may seem quite small," says NIABs head of sugar beet Simon Kerr.
But over a longer period the advances offered to producers are highly significant.
The fact that only four of the 16 varieties on the 2002 Recommended List were introduced before 1999 proves the point, says Mr Kerr.
Although growers income remains the key trials sifting device, a wide range of characteristics are tested to guide selections.
"The only slight drawback at the moment is that the level of bolters in some of the newer varieties is higher than we like to see," says Mr Kerr.
Better varieties are the main reason Mark Ireland of Grange Farm, North Rauceby, Lincs, last years farmers weekly/Du Pont Sugar Beet Grower of the Year, has been able to cut his crop by nearly 20% in the past five years.
"We still have the same quota, but last year we grew only 166ha. In 1996 we had 202. Clearly things like better agronomy and harvesting have helped, but breeding has an awful lot to do with it."
For spring 2002 sowing there are five new options. Mr Ireland is already testing one of them, Humber, for British Sugar. It is top of the list for growers income. "I cant see a lot wrong with it," he says.
A lot of time is spent looking at different varieties for Grange Farm. "Wherever possible we keep them in separate fields and store them separately. I am convinced some are more suited to our farm than others."
Mr Kerr admits the fairly rapid turn round of varieties is making it harder to determine which these may be, though it is a relatively small price to pay for the other benefits.
Most of Mr Irelands crop can usually be sown early on light heathland soils, but some beet is grown on medium loam. Key variety attributes he looks for are good establishment and bolting resistance.
Triploid types are favoured for their ability to cover the ground quickly. For that reason he ruled out Roberta, a diploid, despite it topping the 2001 list.
Newcomer for 2002 Priscilla is also unlikely to feature because of its tendency to bolt. The same could be said of Stallion which produced a late flush of bolters last year from a Mar 15 sowing. But he is sticking with it for another year because of its high sugar content.
"We hand-rogued it twice in August, but by the middle of September the bolters were like a forest." A trial corridor of Delitzsch varieties in the same field stood out clearly with far fewer bolters, he says. "Sugar content is also important to us. On our soils we never get a very large tonnage of roots, so I am less interested in root yield figures."
None of the crop is irrigated and the five-year mean clean beet yield is 51.3t/ha (20.8t/acre), with an adjusted average of 60.2t/ha (24.4t/acre).
Better establishment, such as in newcomers Humber and Latoya at 86% or the rhizomania-tolerant Concept at 88%, is re-assuring and means the trend to lower seed rates should continue, says Mr Ireland.
"We used to think 80% was good. For most varieties 86% is unheard of. Our seed rates have come down from 1.3 units/ha to 1.1. It means we have bigger beet which my driver prefers because we can get a more consistent top tare."
This season his main choices are Chorus, which becomes fully recommended for 2002 and Triumph, the oldest listed variety joining in 1992. The others are Ariana, Baron, Stallion and Wildcat.
"Triumph does very well for us. Chorus had high root yields last year but was a bit disappointing on sugar content." Compared with Stallion on 18.3%, his best Chorus was only 17.37%.
Wildcat has the lowest level of impurities, a feature favoured by British Sugar, notes Mr Kerr. It is getting another chance at Grange Farm despite recording nearly 10% top tare last year.
"I would like to see how it does this year before deciding whether to grow it again," comments Mr Ireland.
Humber is an obvious choice for next season, he says. But newcomer Murrays high sugar content and low bolting potential are also appealing.
Despite its very low bolting potential and high root yield, Latoyas low sugar content makes it less attractive. Otherwise the mix will remain much as before. *
Concept comment
With no rhizomania on the farm Mr Ireland is not permitted, under the present containment policy, to grow Concept, the latest provisionally recommended variety tolerating the disease. But for growers on infected farms it is a significant step forward, says NIABs Simon Kerr. An establishment score of 88% is the best on the list and it beats all four fully recommended types for growers income. It also tends to bolt less than the other rhizo-resisters when sown early. "It can only be grown on infected farms, although not on infected fields."
GRANGE FARM BEETS
• Triploids for ground cover.
• Bolting, sugar, and establishment key attributes.
• Chorus and Triumph main varieties.
• Also Ariana, Baron, Stallion & Wildcat.
Growers income scores
Fully recommended %*
Roberta 101.8
Triumph 99.8
Chorus 99.7
Alexa 98.7
Provisionally recommended
Humber 103.9
Priscilla 102.5
Latoya 102.4
Murray 101.8
Wildcat 101. 6
Ariana 101.1
Jessica 101.1
Stallion 100.6
Baron 100.4
Provisionally recommended
for special use (rhizo-tolerant)
Concept 102.6
Rebecca 96.5
Rosanna 96.0
Source: NIAB.
*Growers income relative to congtrols.