LA DIVERSITÀ NEI SISTEMI COLTURALI PER LA GESTIONE DELLE MALERBE RESISTENTI DI PIÙ DIFFICILE CONTROLLO

Diversity within cropping systems as the tool for managing the most difficult-to-control herbicide resistant weeds. The cropping systems involved in herbicide resistance often have a low variability in space and time. The resistance situation is complex due to the evolution of multiple resistance and the cultivation of varieties tolerant to ALS-inhibiting herbicides. The weeds most affected by multiple resistance are Lolium spp. and Echinochloa spp. Implementation of the new European legislation on the sustainable use of pesticides (called "Pesticide package") will lead to a further reduction in the available herbicides, hence reducing the opportunity to rotate herbicide modes of action. On the other hand, wide implementation of IPM (IWM for weeds) will increase the variability within cropping systems and therefore decrease the risk of resistance evolution. Resistance management requires the implementation of IPM, which has recently been defined as a holistic enterprise emphasising a systems approach and agroecological processes. It creates synergies by integrating complementary preventive and direct methods drawing from a diverse array of approaches that make use of landscape features, cultural and mechanical methods, plant genetics, biological control agents, biotechnologies, and information and decision support technologies, together with pesticide use as a last resort when addressing situations that cannot be managed with other tools. The implementation of IPM is a continuous and dynamic process which integrates innovative solutions.