Herbicides have consistently contributed to yield increases in crop production for many decades however, those same herbicides are facing the loss of effectiveness because of the rapid spread of weed resistance. Since the first instance of herbicide resistance to triazine herbicides over 50 years ago, resistant biotypes have been observed to the major herbicides numbering more than 150 different weed species due to excessive use of single mode of action (MoA)treatments combined with limited crop rotation practices. In the US, the most well-known broad-spectrum herbicide used in major crops, glyphosate is facing huge challenges due to the appearance of many resistant weed species.
The consequences of the loss of effectiveness of the current herbicide choices, coinciding with an increasing world population with improved living standards, is beginning to present a severe constraint on food security globally. Unfortunately, the agriculture industry has been unable to find any new mechanism in the last 30 years. The absence of choices of novel active ingredients along with the increased costs of developing new entities is forcing the industry to rely on older modes of action which, with limited application, means lower annual yields of the major crops as the number of resistant weed species increases.
The Chemical Genomics group in FMC Agricultural Solutions Discovery has been building ‘Chemistry to Gene’ (C2G) capability to identify new MoAsby applying chemical genomics tools. We have recently discovered that compounds described in WO2017075559A1, are potent selective herbicides with novel action that control many grasses. As a result of knowledge of the mechanism of this area of chemistry, we have extended the work to include a ‘Gene to Chemistry’ (G2C) approach to provide new structural starting points for more synthesis projects.

• IL-Ho Kang(Chemical Genomics, FMC Agricultural Solution, USA)