Date: 09/2020
Clearfield oilseed rape continues to reach new heights with the latest varieties pushing yields, gross outputs and agronomic performance to new levels, says DSV’s Sarah Hawthorne.
 
Many UK growers are starting to see that Clearfield technology adds significant benefits to oilseed rape production over the expected better control of pernicious brassica weeds, she explains
 
“The Clearfield system of Imazamox herbicide and oilseed rape varieties resistant to it has made reliable control of problem weeds such as charlock, runch and hedge mustard a reality in recent years.
 
“The system’s efficacy is such that even fields that have been out of production for many years due to large burdens of these weeds, can be made suitable for oilseed rape once more.
 
“Furthermore, many growers had identified the high cost of pre-emergence weed control from metazachlor-based products as being one of the most expensive elements of their establishment management.”
 
The added flexibility Clearfield provides around early weed control strategies means the technology can also be used help fine-tune time of drilling and reduce competition during establishment, she adds.
 
“The ability to control pernicious brassica weeds effectively has been a huge benefit to many growers. It’s also allowed many to adopt a cost-effective ‘wait and see’ strategy without frontloading costs at the start of the season.
 
“As well as allowing better control of difficult weeds, the result for many has been better quality at harvest by reducing erucic acid levels.
“Claims and rejections into the crush have clearly increased in recent years and much of this is down to volunteer oilseed rape as well as weed contamination.
 
“Clearfield is the perfect solution to such issues with one application of the chemistry giving significant control of volunteers resulting in an almost instant improvement in quality.”
 
The DSV varieties Plurax and Phoenix have proved very popular in recent years by combining Clearfield functionality with yields rivalling some of the highest outright yielders on the RL, but new quad layer varieties could lift the bar even higher, Sarah Hawthorne points out.
“Building on the success of our triple-layer oilseed rape varieties, DSV quad-layer varieties are now being introduced adding even greater production resilience and reliability for growers.
 
“Depending on the variety and its application, the fourth layer can vary to include characteristics such as verticillium wilt tolerance, clubroot resistance or Clearfield technology added to the mix.”
 
There are currently two new DSV quad-layered varieties entering the UK testing system, she explains.
 
“The first of these is a Clearfield variety which features phoma stem canker resistance together with TuYV and pod shatter resistance.
“This will sit well alongside the other layered varieties in the Clearfield portfolio and the incorporation of TuYV resistance will reduce dependency on insecticides to control the vector of what is becoming a significant disease in the UK.”
 
The second quad-layer variety is a high output hybrid oilseed rape featuring multi-gene phoma stem canker, TuYV, pod shatter and clubroot resistances.
 
“With clubroot an increasing problem in the Borders and Scotland this will be a variety particularly relevant to the North of the country, although there are signs that the disease is becoming an issue across the UK now.
 
“Developments such as these will ensure all DSV oilseed rape varieties, including Clearfield ones, will offer growers even greater advantages in the future.”