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Protecting your Spring Barley from Blackgrass

Agronomy Issues
09.03.2021
Spring barley early emergence

Spring made its first appearance in many parts of England at the end of February, which meant drills started to roll in some areas.  In the east of England, the winter crops are perking up and fields are starting to look a lot greener.  As the crops grow, so too do the weeds.  Spring cropping in general is a great way to reduce blackgrass populations, as it allows for a flush of weeds to emerge before drilling which can be sprayed off or cultivated to reduce populations.  Spring barley is a very competitive option, far more so than spring wheat, due to its higher tillering capability and thicker canopy. 

The benefit of spring barley is its versatility.  Unlike winter barley, spring malting barley varieties are often amongst the highest yielding varieties, so they can be sold into both a quality market and give the highest yields as a feed variety.  If you chose a variety with MBC approval for both brewing and malt distilling such as LAUREATE, you open yourself up to 3 potential markets.  

Increasing seed rates and early N can help to produce a thicker crop to increase suppression of blackgrass.  If the aim is to achieve grain for a quality market, be wary that increasing seed rates too much can negatively impact screenings and may therefore fail maltsters specifications.
 


Pre-emergence application

Even in spring crops, pre-emergence applications are an important tool in reducing blackgrass populations, both in-season and for future crops in the rotation.  Getting the herbicide where you want it will increase the effectiveness of the product and reduce the risk of it having a negative impact on the environment.  Reducing drift is one way to do this.  There are many different factors which will affect drift

  • Boom height
  • Forward Speed
  • Water Volume
  • Drift Reduction nozzles 

 

Setting up your sprayer

 

 

Boom height

Boom height is the single biggest controllable factor of drift; double the boom height can mean 10x more drift.  Ensure boom height is 50cm above target, which for pre-em applications is the soil.

 

 

Forward speed

Lower forward speeds can help keep the boom lower and more stable, Syngenta advice is 12 kph and below.

 

 

Water volume

In Syngenta trials 200l/ha has given the most consistent performance, regularly giving the best blackgrass control.  Water volumes lower than 200l/ha have more variable performance. 

 

 

Drift reduction nozzles

Using 90% drift reduction nozzles ensure there is an even deposition of the product across the target, as the droplets are not lost due to drift.  This allows the spray to be applied at the right time giving flexibility to the operator and not being dictated to by the weather.