The importance of thinking small

Just think what a crop protection active ingredient has to achieve. It has to kill or disable a crop pest quickly and effectively, but at doses that don’t cause ill effects to humans, beneficial insects like bees, wildlife or the wider environment.

Active ingredient needs to be highly poisonous to the crop pest, but more or less harmless to everything else. That’s a lot to ask of what is little more than a collection of atoms. But such molecules form the central active ingredient of every crop protection product. They work by binding to a cellular target within the plant pest, such as an enzyme. This stops some essential biological processes from working correctly, thereby killing the pest. It is the job of our crop protection scientists to discover these molecules.

In the past, this was achieved via a process nicknamed ‘spray and pray’. As its name suggests, this involved spraying plant pests with different molecules and then picking out those molecules that seemed best at killing the pests. Although it worked, this process is not particularly efficient and meant that for a long time scientists had little idea of the mechanisms by which many crop protection products actually worked.

Nowadays, the ‘spray and pray’ approach has been joined by a whole host of cutting-edge laboratory technologies, such as computer modeling and genetic profiling. As a result, not only can our scientists quickly understand the mechanism responsible for a molecule’s pest-controlling ability, but they can accurately model the interaction between the molecule and its cellular target. This allows them to develop versions of the molecule that are even more effective. It is even giving them the ability to design new crop protection molecules from scratch.

These new technologies have made the discovery of novel active ingredients a communicative process. A potentially interesting molecule will spend time bouncing around between BASF scientists from many different disciplines. Through understanding how the molecule works and rationally altering its structure, these scientists will customize the molecule until it possesses just the right mix of properties.

There is still a role for ‘spray and pray’, but it has been miniaturized, automated and improved. So now novel molecules are tested on tiny leaf discs or insect larvae housed within tiny wells, with 96 of these wells fitting onto a single wallet-sized plastic plate. This allows BASF scientists to test more than 100,000 different molecules a year.