Resistance can be described as an adaptation of a pest population to a pesticide resulting in less efficacy. The resistance organisms are able to pass on this decreased susceptibility to their offspring. If resistance to one active ingredient confers resistance to another plant protection product, we talk about cross-resistance. Resistance is driven by natural selection which allows organisms with resistance genes to survive and pass it to their offspring. This way the number of resistant individuals in a population will increase by continuous applications of a pesticide until the product is no longer effective.

Selective compounds are, together with beneficial organisms, the basic tools for IPM driven sustainable horticulture. However, the number of active ingredients has gone down dramatically over the last decade, certainly in Europe. This means that the resistance pressure on the remaining compounds is getting higher and higher. As a consequence new active ingredients are quite often overused from the start, leading to possible resistance problems. IPM Impact is convinced that anti-resistance strategies, both for chemical and biological pesticides, are an essential part of an IPM approach. Therefore, we support the FRAC and IRAC approach by providing through this website a platform for growers and advisors for the anti-resistance strategies that are worked out by FRAC and IRAC. In the near future, these strategies will be implemented in the side-effect database, so each time the database is consulted for an active ingredient, recommendations and alternatives to avoid resistance will be given on a growers level.


IRAC - FRAC working groups

The Insecticide Resistance Action Committee (IRAC) was formed in the eighties . Its aim is to prevent and delay the development of resistance in insect and mite pests . IRAC is comprised of scientists and specialists of the agrochemical and public health companies. The committees are organized as a network of local working groups with IRAC International acting in a coordinating role. The first role of IRAC is to support communication and education in insecticide and acaricide resistance and to promote the development of resistance management strategies.

The Fungicide Resistance Action Committee (FRAC) follows a similar approach towards prevention of developing of resistant fungi. This group was also formed in the eighties and consists of several working groups on fungicides with a specific mode of action. They developed several bio-assays for monitoring the development of resistance in the field.


For more information on resistance and resistance management consult the IRAC and FRAC websites:

IPM Impact performs resistance monitoring studies on a number of insects and mites, so that the resistance can be managed. This way resistance can be prevented or the population can regain susceptibility.