TOPIC 9: Mode of Action and Resistance

Modern crop protection is still largely depending on the judicious application of agrochemicals to control invertebrate pests such as insects, mites and nematodes, and weeds and diseases. The availability of chemical classes with different modes of action (MoA) is of utmost importance to design sustainable resistance management strategies. New legislation has continued to put pressure on the pesticide portfolio in some regions of the world, making the development, registration and commercialization of new modes of action more crucial today. In addition, if resistance evolves, the understanding of molecular and genetic mechanisms are important to understand cross-resistance issues in order to implement appropriate resistance management tactics to protect fungicides, herbicides, insecticides, but also nematicides, which only recently gained more attention. Resistance monitoring programs, including both bioassay work and molecular diagnostic tools, help to determine resistance allele frequency - particularly the presence of mutations driving targetĀ­ site resistance - and thus aiding product choice for optimum efficacy and sustainable control. Likewise, the elucidation of mechanisms underlying metabolic resistance are crucial to understand the reactivity of molecules in vivo, and provide a potential tool to screen for cross-resistance issues with novel compounds. The field has recently gained momentum by a number of genomic and genetic tools, that have allowed to dissect molecular interactions between agrochemicals and interacting proteins, a key topic of this session.

Key words

Fungicides, herbicides, insecticides, mode of action, resistance management, genomics, target-site resistance, metabolic resistance

For further information, please contact the organizers

International Lead:
Ralf Nauen, Bayer AG, Germany, +49 21 73 38 44 41,

Regional Lead:
Thomas van Leeuwen, University of Gent, Belgium, +32 9 264 61 43,



Fungicides: Mode of action and resistance


Herbicides: Mode of action and resistance


Insecticides: Mode of action and resistance


Nematicides: Mode of action and resistance


Genome based technologies in MoA and resistance research