Release Date 06 November 2015


Written By Matt Sherriff

Release Date 
06 November 2015

Written By Matt Sherriff

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Key Points

  • The right herbicide and rate for the weed spectrum.
  • The right adjuvant to maximise droplet survival, leaf coverage and penetration, whilst reducing drift. Depending on the adjuvant used, initial herbicide efficacy and time taken for complete control can vary by up to 50%.
  • The right boomspray setup – coarse nozzles for drift control and high water volume for best coverage.
  • The right adjuvant – new independent research indicates that in glyphosate and ester mixtures, high emulsifier loaded oil-based adjuvants such as ENHANCE® and ANTIEVAP® provide the best efficacy on a range of summer weeds such as melons, fleabane and feathertop Rhodes grass.
  • Benefits of the double knock – importance of coverage and leaf penetration for non- translocated herbicides.

SACOA’s recent fallow research

Over the last summer SACOA invested heavily in independent field research throughout Australia, assessing the effectiveness of various adjuvants with common summer herbicide mixtures on key weeds such as fleabane, melons and feathertop Rhodes grass – with some surprising results. This independent work has been conducted with extensive industry collaboration to answer key questions;

  • Droplet survival – what does it mean?
  • What’s the best balance between coverage and leaf surface penetration?
  • What are the efficacy differences between adjuvants – oils vs non-ionic surfactants vs seed oils vs soyal phospholipids?

Coverage and droplet survival

Getting herbicides onto and into weed leaves can be tough in summer conditions with drift, evaporation and run-off all contributing to loss. Increased droplet survival allows herbicides more time to enter into weeds, so getting herbicides to work well under summer conditions requires a balance between leaf surface coverage and penetration.

Key findings

Our coverage analysis work found key differences between adjuvants;

  • Non-ionic surfactants such as WETTA 1000® can improve coverage by producing smaller droplets, however these are more susceptible to drift and evaporation and provide little in terms of leaf surface penetration.
  • Soyal phospholipid-based products such as COHORT 700® can increase droplet size and reduce evaporation as well as provide water conditioning benefits but provide little leaf surface penetration.
  • Seed oils such as PLANTOCROP® and X-SEED® tend to produce larger droplets due to their increased viscosity and tend to be more effective with Group A herbicide mixtures on grass weeds due to their penetrative properties.
  • Oil based emulsions, which contain varying degrees of surfactant such as ENHANCE® and ANTIEVAP®, provide a balance between leaf surface coverage and penetration and are therefore best suited to tank mixes of translocated and contact herbicides such as glyphosate and ester.

What does that mean for destroying summer weeds fast?

Melon control

Back in November 2014 we published results from our 2012 independent field research indicating ENHANCE® and ANTIEVAP® provided the quickest brownout on melons compared to other adjuvants such as LI700®. Our latest research, including some of the newer adjuvants to the market supports this.

Key findings

  • In Garlon® + Ester + Ally® mixes, clear rate response between Enhance at 0.5% and 1.0% 8DAT.
  • In Glyphosate + Garlon® + Ester + Ally ENHANCE® mixes, both ENHANCE® 1.0% and WETTA 1000® 0.5% provide the quickest brownout 8DAT.
  • Soyal phospholid-based products COHORT 700® and Liberate® provided relatively poor control in both mixtures at all assessment timings.

  • In mixtures of Glyphosate + Ester + Ally® the oil-based adjuvant with high emulsifier loading (ENHANCE® 1.0%) and non-ionic surfactant (WETTA 1000®) provided the best control.
  • Soyal phospholid based products COHORT 700® and Liberate® provided relatively poor control at all assessment timings.
  • Seed oil based products X- SEED® and Infiltrator® were equivalent in fleabane control

  • Gramoxone 1.5L/ha applied 14 days after the initial application improved control in all treatments.
  • Using an oil-based adjuvant with greater penetrant properties such as ENHANCE® proved superior to non-ionic surfactants in mixtures with Gramoxone, averaging 10% greater control in all treatments.


Trial SE145 – Agvivo Agronomy
T. Boyes Quairading Dec 2014
Trial SE146 – Agvivo Agronomy
T. Boyes Quairading Dec 2014



Disclaimer and Copyright

This document should act as a guide only and no purchase or usage decisions should be made based on the information provided without obtaining independent, expert advice. SACOA and contributors do not necessarily recommend or endorse any products or manufacturers referred to. SACOA Pty Ltd will not be liable for any loss, damage, cost or expense incurred or arising by reason of any person using or relying on the information contained in this document. More information is available from SACOA via or 08 9386 7666, or by contacting your local reseller.
© 2019 SACOA Pty Ltd All Rights Reserved. SACOA and the GREEN S icon, ENHANCE, CROPSHIELD, PLANTOCROP, BIOPEST, XSEED, ANTIEVAP, STIFLE, SE14 and LURE H2O are registered trademarks of SACOA Pty Ltd.