In the second of the iOSR series, members of Syngenta’s UK oilseed rape growers’ group visited Germany to learn how the company is developing the crop’s potential.
Oilseed rape yields will increase rapidly because of new hybrid breeding techniques and greater focus on the requirements of speciﬁc European markets, Dr Stephan Pleines, head of OSR breeding for Syngenta told the group.
Research at the company’s OSR and hybrid barley seed breeding facility in Bad Salzuﬂen is maximising the beneﬁcial heterosis effect during hybridisation, which triggers greater plant vigour and performance. Whereas in 2012 the heterosis potential was 8-12%, by 2020 it could reach 25-35%.
Dr Pleines said: “Heterosis depends on the diversity of the parent lines. The greater the genetic disparity between the two parents, the greater the potential for hybrid performance.”
Breeding decisions made up to 40 years ago focused almost exclusively on low erucic acid and low glucosinolates, causing the genetic base of OSR to become very narrow, but now Syngenta is identifying, developing and increasing genetic diversity to boost the hybrid programme.
“While hybridisation is great for growth characteristics, there’s no heterosis effect for oil content, so you need male and female lines that both have high oil content, which is far more difﬁcult to achieve,” Dr Pleines added.
Molecular markers have revolutionised breeding techniques and the speed with which useful traits are developed. It also facilitates stacking resistance genes to produce more robust varieties and facilitate new developments. TuYV tolerance, for example, is increasingly vital throughout Europe because of fewer insecticide protection options, with Syngenta varieties being in ofﬁcial trials and prioritised through internal trials. New Phoma resistance RLM genes have also been identiﬁed as working, but not yet been released.
“Over the past 20 years we have seen yield potential increase by about 1.4% year-on-year,” Dr Pleines said.
“Hybrids have accelerated that process and I would expect it to continue or increase due to more intelligent selection and new genetics.
“Hybrid vigour gives oilseed rape plants the potential for quicker emergence in autumn and faster re-growth in spring, with the development of larger root diameter and greater root mass.
Stronger plants are more tolerant of abiotic stresses, such as heat, cold, drought and nutrients, along with pest and disease pressures.
While genetic potential has to be utilised alongside agronomic inputs, it gives increased opportunity and ﬂexibility to achieve consistently higher performance.”
Dr Pleines said varieties for UK markets were selected primarily for high seed yield and oil content, along with other agronomic traits, such as resistance to lodging and light leaf spot together with autumn vigour, a special requirement given the pest pressures and need to establish a higher plant population under optimum conditions.
“The UK differs from most of Europe in conditions are typically relatively mild through winter and early season through to ﬂowering, then cooler and duller until harvest compared with mainland Europe. Relatively, the UK is cold at seed maturation, which requires very speciﬁc variety characteristics.”
With most UK growers ﬁnishing sowing oilseed rape by the end of August crops here are typically two to three weeks ahead of those in France and Germany. This is reﬂected in higher seed rates and plant populations.
Gary Jobling, Syngenta’s European oilseeds manager, said: “In the UK, conventional varieties are typically sown at 70-80 seeds/sq.m and 50/sq.m for hybrid varieties. In Germany, hybrids are used almost exclusively at 35-45 seeds/sq.m and in France mostly 35-40/sq.m.”
Increasingly UK growers are applying up to 30kg/hectare N in autumn, but in France it would rarely be used. Growers in Germany have historically applied 20-40kg/ha N at this time, but many now believe it only creates leaf area, with no beneﬁcial effect on autumn rooting or ﬁnal yield.
In spring, French growers apply the least N, typically 120-170kg/ha, in two or three splits, whereas in Germany N use, which had widely been up to 220kg/ha, has generally been reduced to 180kg/ha, compared with 180-230kg/ha in the UK.
One further agronomic difference between countries is whereas more than 70% of UK OSR crops are chemically desiccated or swathed, in Germany very few are and none in France.
In the east of Germany most oilseed rape is grown on larger farms which average just more than 1,000ha with of OSR 188ha, about 20% of the cropped area. In western Germany the average farm is under 150ha and the OSR area around 25ha, 15% of cropping.
At 1.3 million hectares, OSR is the third largest crop in Germany, after wheat (3.3m ha) and maize (2.4m ha). Most large farms grow three or four varieties, with hybrids accounting for 1.14m ha (88%of the area), said Syngenta OSR manager Alexander Wendel.
In 2014, oilseed rape crops throughout Germany suffered severe losses from ﬂea beetle, with no exemption for using neonicotinoid seed treatment, even in the worst affected areas. The following year most growers heeded advice to delay sowing in autumn and losses were far less, although Clubroot was especially bad and is an increasing problem. New third-generation Clubroot-resistant varieties have shown clear yield advantages and are being adopted more widely.
German growers have also been quick to adopt new PGR technology for crop management. They use an autumn application of Toprex (paclobutrazol + difenoconazole) to encourage rooting, enhance overwinter hardiness and improve control of phoma, followed by the standard spring application used by UK growers against light leaf spot and to manipulate crop architecture for leaf area and synchronised ﬂowering.
When it comes to sclerotinia, German growers are experiencing a similar intermittent problem to those in the UK and increasingly look to Symetra (azoxystrobin+ isopyrazam). Typically used at the start of ﬂowering, Mr Wendel said Symetra provides a long window of protection from disease, but also promotes green leaf retention and physiological plant enhancement, which has consistently produced higher yields even in years when little or no disease was present.
HEIKO Lemburg achieved an average oilseed rape yield of 5.2 tonnes/hectare on his farm in northern Germany.
A pioneer of conservation tillage, he reported similar problems of flea beetle and struggles with fertiliser limitations. But, black-grass is still susceptible to sulfonylurea herbicides –which he is making every effort to protect.
Use #iOSR to join the discussion
iOSR is a new initiative from Syngenta, published exclusively by Arable Farming magazine, to give growers and agronomists a deeper insight into oilseed rape production.
It will combine expertise from across the industry, with in-field science from Syngenta innovation centres and the practical experiences of a group of successful growers aiming to deliver timely information and intelligence to enable more informed decisions for crop agronomy.
To read more about the project and hear from some of the growers involved visit: www.fginsight.com/iOSR. In addition, you can ask Syngenta OSR questions and join iOSR discussions on Twitter by using #iOSR.
Visit the series hub for more articles, links and project information.