CEREALS 2010: Syngenta showcases new double-tolerant variety
28 June 2010 | Powell Richard
Providing growers with an affordable answer to Beet Cyst Nematode (BCN), the UK's market-leading sugar beet seed company, Syngenta, believes their new double-tolerant variety SENTINEL is the most exciting sugar beet variety it has launched in the last ten years.
SENTINEL is not the first UK variety to be resistant to Rhizomania and tolerant to BCN, but its value stems from delivering good yields on both infected and uninfected parts of the field, according to Syngenta's Richard Powell.
"In the early stages of trait development, it is not unusual for varieties with the new trait to have a yield penalty compared to varieties without the trait - the so-called 'yield drag'," said Mr Powell. "In these instances, growers must balance the potential yield benefit to be gained from infected areas against the yield reduction of the yield drag on the uninfected portions of the field. However, our new variety, SENTINEL, as well as providing yield increases of anything up to 85% in seriously infected patches of BCN, delivers yields within 0.5% of the control mean on uninfected land, virtually eliminating the yield penalty.
"With a yield penalty of 5% you need to be certain that 8-10% of the field is infected to make it worthwhile growing a tolerant variety. However, with the penalty reduced to just 1%, SENTINEL becomes a viable proposition if just 1.5-2% of the field is infected."
This makes the choice as to whether or not to grow a BCN tolerant variety a lot easier and Syngenta expects that the double-tolerant segment of the UK market will expand. This is currently less than 1% of the UK crop area, where the extent of BCN infection is not fully known.
However, in Sweden, which has an extremely good correlation to UK conditions for variety performance, the so-called double-tolerant varieties will account for some 45% of the national crop area in 2010. This is despite the fact that only 30% of the beet growing land is above the guideline threshold of 1 egg/larva per gram of dry soil for growing a BCN tolerant variety. In Sweden, Syngenta's double-tolerant varieties account for 87% of the seed used for this market segment, with a sister variety to SENTINEL accounting for 32% of the national crop.
Richard Powell suggests that growers might follow the Swedish experience. "BCN is not easy to spot at lower levels of infestation. You could consider growing a strip of Sentinel across an infected field to see the difference that will show the presence of nematodes. With virtually no yield penalty on uninfected land this is an economic way to find out."
Sentinel is also distinctive in being suitable for early drilling, with the lowest bolting from early sowings of any Rhizomania resistant variety. "Even where BCN is less likely to be a problem, we know that growers who need a Rhizomania resistant variety have been keen to find one that will allow them to drill as early as conditions allow, which can make a 10% difference to yield," advised Mr Powell.
Looking at all the factors affecting crop performance, the key drivers for sugar beet growers continue to be yield, sugar content and low bolting. This is the combination which has resulted in Syngenta's conventional varieties - SARACEN, TRINITA and OPTA - making up the largest part of the current crop. Many growers have broken the 100t/ha barrier with these conventional varieties as sugar beet yields continue to grow.
According to Richard Powell, a number of factors are contributing to this growth. "The ability to drill as early as conditions allow is acknowledged to have up to 10% impact on yield. Other factors such as good rapid ground cover, large canopies, green leaf retention, easier harvesting, lower dirt and crown tares and reduced transport requirements all need to be factored into growers' choice of varieties. "
