Clearfield® Weed Control
20 Sep 2018
With 14 Clearfield varieties available this autumn, the area of Clearfield oilseed rape is expected to have significantly grown again this year, up from the 60,000ha planted area in 2017. More and more growers are choosing Clearfield for reasons beyond its well-established ‘problem’ weed control capabilities. However, getting the herbicide application right is still key when it comes to getting the most out of the system.
The Clearfield® Production System
Clearfield combines high performing OSR varieties with post-emergence herbicides, designed to work together to protect your crop and minimise your risk. Clearfield varieties have been developed using traditional plant breeding techniques and are tolerant to imazamox-based Cleranda (imazamox + metazachlor) and Cleravo (imazamox+ quinmerac).
The post-emergence, contact and residual activity of Cleranda and Cleravo provide the broadest spectrum of weed control of any available herbicide in oilseed rape, including brassica weeds, volunteer oilseed rape, volunteer cereals and broadleaf weeds.
Both Cleravo and Cleranda offer very similar broad-spectrum, weed control and can be used as a one-shot option. However, where high populations of weeds that get big quick are anticipated, such as crane’s-bill, poppy or mayweed, Cleravo allows the option of an early application of metazachlor or Springbok to sensitize them.
How to get the most out of Clearfield®?
Good agronomy is needed to get the best from the Clearfield system and below are some key pointers which will allow growers to maximise Clearfield’s potential.
Two key things to remember
- Timing: Apply to small, actively growing weeds. Target 1-4 true leaves for broad-leaf weeds and 2-3 true leaves (max. 2 tillers) for volunteer cereals. Typically weeds will be at this stage in September and October.
- Foliar uptake: Ensure good spray cover.
- A water volume of 100 l/ha is OK. If it’s a thick crop use angled nozzles, rather than increasing the volume.
- Apply as a medium spray, using flat fan or small droplet air induction nozzles, not coarse
- Allow a minimum of 2 hours to become rain-fast (if applied to a dry leaf)
- Always add Dash HC 1.0l/ha as it improves leaf cover and uptake
- After application, wash sprayer tank thoroughly, as per label.
- Keeping records is also very important. It may be practical to add the suffix ‘CL’ to the field name as a reminder and to help to avoid misapplication of Cleranda and Cleravo to non-Clearfield varieties.
- To control Clearfield oilseed rape volunteers in following crops:
- Reduce the risk of dormancy by delaying cultivation for 2 weeks, if moisture is available, or 4 weeks, if it remains dry. This will encourage an early flush before the next crop and/or within the following one.
- Ensure herbicide programmes in following crops include non-Group B herbicides.
|General BLW, including problem crucifers||Cleravo® 1.0l/ha + Dash® 1.0l/ha|
Cleranda® 2.0l/ha + Dash® 1.0l/ha
|High populations of early weeds expected -|
|Crane's-bill||Metazachlor or Springbok® 1.0-1.5l/ha pre or at cotyledon|
Cleravo® 1.0l/ha + Dash® 1.0l/ha
|Poppy*, Mayweed&*||Metazachlor 1.0-1.5l/ha pre or at cotyledon|
Cleravo® 1.0l/ha + Dash® 1.0l/ha
Cleranda contains imazamox and metazachlor; Cleravo contains imazamox and quinmerac. Astrokerb contains aminopyralid + propyzamide. Cleranda and Cleravo are registered trademarks of BASF. All other products are those of other manufacturers where proprietary rights may exist. *Astrokerb is an alternative option here where propyzamide is already planned for blackgrass
For more information on Clearfield, visit www.agricentre.basf.co.uk/Clearfield