Better varieties for sweeter beet

Sugar yields could potentially double over the next decade thanks to the development of new beet varieties and improved agronomy, according to predictions from German plant breeder Strube-Dieckmann.

Average white sugar yields (WSY) in many European countries are about 9t/ha, but some growers could be hitting 17-18t/ha by 2015, says the firm’s Axel Schechert.

“It certainly is a challenge, but we are trying to reach it.

We’re already seeing about a 1% increase in white sugar yield each year due to better varieties.”

Various factors will play a key part in achieving higher yields and Dr Schechert highlights the continuing trend towards rhizomania resistant varieties, as well as improvements in disease resistance and sugar extractability.

“Rhizomania resistance has increased in importance over the past 10 years and 80% of seed production is now resistant.”

He dismisses fears over the stability of the main resistance gene (called “Holly”), which originated from a source found in California in the 1980s.

“There is no reason to believe it can’t stand existing disease pressure and we wouldn’t expect any problem in the near future.

Even if Holly doesn’t work in the future, we do have other resistance sources in new varieties.”

Modern varieties also offer better sugar extractability.

“Some of the first rhizomania resistant varieties were not as good as classic types, but new material has shown a 10-15% improvement in reducing impurities (eg, Potassium, Sodium and Amino-N).

We expect a lot more improvement in the next few years.”

In terms of disease resistance, Dr Schechert says that while some of the early rhizomania resistant varieties were more susceptible to rusts, there is little or no difference now.

Choosing varieties with good disease resistance gives more flexibility with spray timings and will be especially important for those with late-lifted beet, he adds.

He urges growers to consider using fungicides, as trials have found that average white sugar yields can be about 1t/ha higher in treated crops, compared with untreated.

“Treat your beet, otherwise you will lose yield,” he says.