|Version 2||Date January 2020||Reference 24|
SACOA set out to prove with actual infield efficacy trials the best herbicide and adjuvant combinations for controlling difficult weeds. A number of independent replicated field trials have now been completed across NNSW, Southern Queensland & Western Australia.
The results from these have provided some interesting takes on traditional herbicide mixtures and proved the role of different adjuvant types – emulsified mineral oils, esterified seed oils, non-ionic surfactants and soyal phospholipids – in spreading and penetrating actives on leaf surfaces.
Multiple tank mixes are becoming increasingly prevalent, particularly for pre-plant and early post emergent applications where getting across large areas in a timely manner is critical.
Unfortunately water is often not a great carrier for agricultural chemicals as it is a charged polar molecule and variability in water temperature and quality can affect how well products dissolve into it. When the cost of product in a spray tank is considered, it pays to ensure that they are mixed correctly.
Most agricultural chemicals are formulated to be as emulisifiable as possible, but many contain elements that either do not dissolve well (wettable powders – WP’s and water dispersible granules – WDG’s), petroleum distillates (emulisifiable concentrates – EC’s) or just precipitate, as they are heavier than the water (fertilizers, powdered metals, etc). Care should be taken when using these, particularly when under time constraints.
This technote describes correct mixing techniques to optimise active ingredient activity by maintaining them in suspension in the spray tank during the entire spray operation. Adjuvants and compatibilisers such as N-Flow® play a major role in bonding the otherwise unmixable spray materials with water.
|Chart 1: Control of Fleabane with Paraquat + Ester mixtures and Glyphosate + Ester mixtures with various adjuvants. (Source: T Boyes AgVivo Agronomy, York Feb 15)|
|Image 1: Melon Control – East Quairading December 2014|
|Graph 2: Control of Fleabane with Paraquat + Ester mixtures and Glyphosate + Ester mixtures with various adjuvants. (Source: T Boyes AgVivo Agronomy, York Feb 15|
|Graph 3: Melon Control with Glyphosate mixtures and various adjuvants (Source: T Boyes AgVivo Agronomy, Quairading December 2014)|
|Graph 4: Melon Control with Triclopyr mixtures and various adjuvants (Source: T Boyes AgVivo Agronomy, Quairading December 2014)|
|Graph 5: Eragrostis control with various common control mixtures and associated adjuvants. (Source: T Boyes AgVivo Agronomy, Quairading December 2014)|
|Image 2: Glyphosate 1.5L + Garlon 80ml + 2,4D 500ml (lv ester 680) + Ally 5g + Enhance 1.0%, 8DAT on 16 December 2014.|
|Image 3: Glyphosate 1.5L + Garlon 80ml + 2,4D 500ml (lv ester 680) + Ally 5g + MSO 0.5%, 8DAT on 16 December 2014.|
|Image 4: Untreated control, 8DAT on 16 December 2014.|