PowerMax is the latest brand of glyphosate to be introduced by Monsanto. This is a granule formulation which is said to bring a number of environmental, label and waste benefits for the product. This active is now the world’s largest herbicide and it has been used in the Irish market for 40 years.

Described as the first super-dry formulation, Roundup PowerMax claims to bring many environmental benefits to this important farmer active. The most recent product is just one of the many formulation adjustments in the evolution of glyphosate.

Speaking at the launch, Wolfgang Voegler from Monsanto explained that the formulation changes are mainly driven by registration requirements. The initial formulations needed a lot of added formulation supports to help field activity but some of these substances could bring other issues such as foaming.

Stability over time is an issue for all formulations and the move to a solid formulation is seen as a bonus in this regard. The requirement for efficiency testing for registration drove some of the change and the desire to differentiate the Roundup brand from the others is also likely to be a major driver of improved formulation. Recent regulatory changes drove a lot of additional testing, with information now required on rainfastness, water volumes and individual weed species.

The facts behind the new formulation were explained by Barrie Hunt of Monsanto. Firstly, this is an extruded granular formulation using 1mm granules which contains 720g/kg of glyphosate. This makes it a high-load concentrated formulation which requires less volume per hectare, fewer packs to store and transport and it leaves no potentially hazardous waste after use.

It is dust free and dissolves fast in the induction bowl. It is much less affected by the quality of the spraying water than previous Roundup formulations. Its surfactant system contains a mix of different formulation actives which combine to provide the benefits claimed. The surfactant system contains:

  • Cationic activity which is useful on the leaf surface.
  • A non-ionic element component which helps to prevent metal complexing in hard water situations.
  • An ammonium sulphate element helps uptake and activity and also helps to inhibit metal complexing.
  • The patented granule uses an ammonium salt formulation in conjunction with surfactants which provide improved rainfastness, reduced risk of drift and improved use efficiency.

    More robust

    A major claim for the new PowerMax formulation is that it is more reliable under challenging climatic conditions such as cold, heat or drought. This can be particularly useful at certain times of the year to help make best use of limited weather windows.

    Improved efficiency is also claimed for this new formulation. A range of trial results were presented which showed faster and longer kill and Barrie indicated that this was a result of more actual glyphosate being delivered into the root system. Results also indicated that it was a superior product for oilseed rape desiccation.

    The new formulation also has altered recommended intervals for cultivation. It only requires six hours prior to cultivation for annual weeds; a two-day interval for common scutch; and five days post spraying for other perennial weeds.

    All of these things combine to give PowerMax a clean label. It is deemed to be non-hazardous in current pesticide legislation and it is approved for use in aquatic areas. This brings benefits for the operator and the environment.


    PowerMax comes in a 10kg bag and its concentrated formulation means fewer containers to handle. And the clean granule formulation means that there is need to triple-rinse empty containers as over 99.9% of the product will be removed. All in all, this sounds like a good option for farmers but relative price will inevitably be a consideration.

    Recommended rates of use depend on the target plants. These range from 0.5 kg/ha for harvest management, 2.0 kg/ha for oilseed rape desiccation, 3.0 kg/ha for grassland and 5.0 kg/ha for forestry. Individual target weeds are very rate specific and so users must consult the label to get the most appropriate rate.

    New focus

    Also speaking at the launch, Patrick O’Reilly of Monsanto said that the company is now focusing on biological control systems within agriculture and also on integrated farming systems. Biological products are being examined for their potential to complement current technologies to help reduce, minimise or prevent problems from occurring.

    More and more companies are looking at this area. The suggestion is that many such products are likely to be delivered as seed treatments to target both the reduction in the prevalence of pest problems and also to increase the general health status of the plants.