New Beet Variety Offers Alternative Rhizomania Protection Gene

KWS UK has launched its second sugar beet variety containing the new Rz2 gene that gives tolerance to new strains of Rhizomania.

Sandra KWS becomes the highest yielding variety in a new category on the BBRO Recommended List for 2014 and is specifically recommended for situations where the AYPR strain of Rhizomania is suspected or confirmed.

It joins sister variety Isabella KWS on the UK Recommended List, which was recommended last year and has been planted in AYPR situations across at risk beet growing regions this season.

According to KWS UK sugar beet manager, Simon Witheford, at 99.2%, Sandra KWS offers a significant adjusted yield advantage over Isabella KWS.

“With yields outside an AYPR infestation ahead of some recommended varieties Sandra KWS was probably unlucky to miss out on full recommendation and could be grown on the back of this yield performance alone.†

“It is 4.7% higher yielding than Magistral, the other newcomer in the AYPR category, and this should give it wide appeal for those who want to maintain yields and yet employ an alternative rhizomania resistance strategy compared to other varieties,” he says.

The AYPR strain of Rhizomania has been identified in over 30 UK situations and is now believed to have been present in our soils for 20 years or more.† Most current Rhizomania resistant varieties don’t contain the gene capable of tolerating the AYPR strain and when grown in infected soils could see up to a 70% loss in root yield and a 22% reduction in sugars.

“This is why we have been working on introducing a new Rz2 gene into our varieties; something that has been recognised by the BBRO in the new AYPR tolerant category on the 2014 Recommended List,” says Mr Witheford.

While he suggests growers who suspect they have the more aggressive AYPR strain in their fields should have soils checked, varieties like Sandra KWS are available and could be grown in all situations.†

“Those who feel that yields in recent years may have plateaued or could be in decline, could test Sandra KWS in their own fields – perhaps alongside current varieties – to see if this can be reversed.”†

“Varieties such as Sandra KWS – with the Rz2 gene - have already been adopted in countries with AYPR issues such as France, Holland and the USA,” says Mr Witheford.

“While the incidences of confirmed AYPR resistant strains remain low across most of England, UK growers adopting the new technology in Sandra KWS will not compromise its long term performance.† Unlike the first varieties containing the Holly gene Sandra KWS brings no significant yield penalties and, through reducing the availability of potentially resistant host plants, growers can effectively reduce the development and multiplication of any resistant strains of rhizomania,” he says.

Sandra’s high adjusted yield comes from a root yield of 97.7% and sugar yield of 99.0%.† Its sugar content – at 18.73% - is third highest on the Recommended List.

Mr Witheford also points out that Sandra KWS also has good agronomic characteristics with rust and mildew scores of 4.5 and 4.7 – better than the vast majority of other recommended varieties.

†“We see it as the ideal selection for those looking to adopt new technology and spread their rhizomania risks.† Sandra KWS is just 3% behind the Recommended List leader – new variety Stingray and that’s a small yield penalty when you consider its potential to tolerate new strains of rhizomania,” he says.