SURfaPLUS: EAA-Innovations 2018 covers search for optimal spray drop

Adjuvants are continuously tailored to the latest requirements. With a one-day innovation meeting SURfaPLUS stimulates the exchange of ideas and views about these requirements and trends. Nine presenters shared their insights and thoughts, with a focus on the optimisation of drops and sprays. A mini market completed this well-attended symposium in the dynamic Dutch port city Rotterdam.


In search for the optimal spray drop. That was the focus of several adjuvant and formula¬tion specialists presenting in Rotterdam. Researchers have increasingly sophisti¬cated techniques to conduct their studies into the performance of spray solutions. If a suitable method is lacking, then they develop their own techniques. And so it happens that participants in the first European Agrochemical Adjuvants Innovation Meeting (EAA-Innovations 2018) are informed about innovations with formulations, drop deposits and the foliar uptake of active ingredients.Take for instance the detailed study of scientists at the University of Würzburg, presented in a poster at the mini market of this symposium. The German researchers are investigating the contribution of specific cuticle wax fractions to the cuticular permeability of active ingredients. They focus on the interaction of active ingredients and adjuvants with different wax fractions.

Volatility
In-depth knowledge and practicial insights alternate during this one-day symposium. Keynote speaker Dan Wright (Monsanto) opened the batting with a sketch of the developments of formulations in the past decades. In front of a crowded hall he explained very well the influence of different formulation types on the volatility of auxin herbicides like dicamba. He told how adjuvants and formulations can contribute to improved targeting and lower emission of herbicides. Using tallow amine and alkyl polyglycoside surfactants as examples, he illustrated their different influence on uptake and translocation of labelled glyphosate.
Volatility was also the topic of the presentation of Michael Houbraken (Ghent University). He shared his insights in the influence of solvents and formulation types on the volatilisation of 2,4-D, fenpropimorph, pyrimethanil and tebuconazole. In his study he focuses on ‘regular’ formulation types like emulsi¬fiable and suspension concentrates.

Drift
Drift reduction is a recurring theme at symposia about agrochemical adjuvants and formulations. Daniel Bonn (University of Amsterdam / GreenA) devoted his entire presentation to this topic. With polymers as spray additive he manages to selectively reduce spray drift. “We want to suppress small drops, while not changing the average size too much”, he said. Nozzles and surfactants are not suitable to selectively suppress the formation of small drops, according to the co-founder of the start-up company GreenA. Through this Dutch company he commercialises his findings in form of a controlled-release polymer additive formulation that is branded Squall. Bonn also proudly presented his formula that predicts the drop size of spray solutions that are not yet supplied with a polymer adjuvant.

Difficult-to-wet
Adjuvants – whether built-in or tank-mixed – can greatly enhance the performance of foliar-applied crop production products. They play a key role when difficult-to-wet leaf surfaces are targeted, according to Christian Popp, team leader in the formulation / application group in Syngenta Switzerland. “Adjuvants play an even more important role when difficult to wet leaf surfaces are targeted with increased droplet sizes”. In his presenta¬tion he addressed the importance of the actual amount of product retained on the leaves: “Leaf coverage doesn’t necessarily correlate with the actual amount of product retained on the leaf”.

Big data
Drones are increasingly used for spray application, but the retention is a disaster, says formulation expert Ronald Vermeer (Bayer CropScience). In his keynote presentation he outlined future trends of formulations and the role of adjuvants. The potential advantages of ‘digital’ will only be visible with optimized or specialized adjuvanted products, so is his take away message to the 130 participants of this fully booked meeting. Due to the emergence of digital and precision farming, spray equipment is getting bigger, smarter and more precise. Vermeer foresees that this will result in a shift from protective treat¬ments as an insurance against pests and diseases to curative sprays. “Big Data will become the new currency”, he concludes. Other drivers for the choice of adjuvant and formulation type are the decreasing bioavailability of new active ingredients – compared to older chemistries, the wider use of biocontrol agents and the social pressure for a greener environment. Due to trends in future formulation types, the need for adjuvants increases, he said.

Biopesticides
Ulrike Malang (BASF) further explored the formulation challenge of bio¬pesticides. She points to trends towards toxicologically and environmentally benign formulation additives and to the use of additives derived from renewable resources. Main formulation topics for microbe-based products are related to shelf life, applicability and biological efficacy, she said. To a certain extent, solutions that have been developed for synthetic active ingredients can be transferred to biologicals. But there are also very specific aspects that shape the trends for new adjuvant needs. She further wondered whether it is possible to develop formulated biologicals that are allowed to be used by organic growers.

Drop deposits
With a presentation about the make-up of spray drop deposits, symposium organizer Hans de Ruiter (SURfaPLUS) wanted stimulate research into this crucial, but still very little explored phenomenon. He discussed the relevance of drop deposit make-up for the performance of foliar-applied crop production products, including foliar fertilisers. De Ruiter questioned whether adjuvants or additives can be applied to design a more optimal drop deposit for the release of active ingredients.
Axa Piñeiro Romero (Durham University) also provided insight into what is happening in a drying drop deposit. She shared research results obtained by a specific experimental set-up with which she explored the deposition of tebucona¬zole onto a model hydrophobic surface.

High throughput research
Companies must be able to respond quickly to developments in the market. Daniel Zweifel (Dow Crop Defense) highlighted the use of high throughput research for the development of crop protection formulations. With this approach it is possible to handle a range of variables and to model test plans and analyses. With this innovative research tool new product discovery can be accelerated, he said with reference to additives like solvents, surfactants, co-formulants and dispersants. High throughput research is also a useful tool to make it easier to understand complex interactions that affect final formulation properties. Other advantages of this approach are the accelerated “time to market” and the enhanced probability to develop successful solutions.

Need for knowledge
EAA-Innovations 2018 – held in between two ISAA symposia – reflects the intense need for information and knowledge concerning adjuvants and formulations. From at least 19 countries attendees went on Wednesday 7 March 2018 to LantarenVenster in Rotterdam, The Netherlands to join the meeting. With EAA-Innovations 2018, SURfaPLUS gave a follow-up to its two successful adjuvant symposia in Amsterdam (2011 and 2015). Sharing of adjuvant and formulation knowledge is a core business of this Wageningen-based company.