By Dr Jim Bullock. Taken from the June 2020 edition of Outlooks on Pest Management.
Whether it is a synthetic or a biological material, the journey of an active ingredient (AI) from manufacture to its target site is a perilous one. Along the way there are numerous opportunities for the AI to be degraded, destroyed or removed.
Following production of the AI, it may be vulnerable to chemical and thermal instability. Again, during formulation and on storage after manufacture, possible physical and chemical instability will need to be considered. Compatibility of the AI and co-formulants with packaging materials will also need to be taken into
During application there are further opportunities for the AI to be lost. In a spray tank there is a risk of physical instability (e.g. particle agglomeration and settling) and of incompatibilities with other products added to the tank such as adjuvants and other AIs.
Once sprayed, the droplets may drift and miss the target area or, even if they reach the leaf, not adhere there. Then, it may not persist on the leaf (or pest) surface or (in the case of systemic AIs) be taken up by the target. Finally, even once taken up by the target, there can be further chemical incompatibilities which degrade the AI.
Many of these problems can be tackled by good use of formulation during product development.
To read the rest of this article go to Outlooks on Pest Management (Jun 2020).