Herbicides are the main weed control tool in most cropping systems around the world, including rice. However, the high dependence of the herbicide has given rise to environmental problems, as well as to the evolution of herbicide-resistant biotypes.

Resistance is an important issue of concern in modern agriculture and the early detection of resistant biotypes is crucial for their management and prevention. In this context, an update of the distribution of resistant biotypes is essential to design and implement efficient resistance management strategies.

In Spain, and within a project funded in a previous INIA call, surveys were carried out in different rice regions of Spain, confirming the presence of weed populations resistant to different herbicides, mainly in Echinochloa spp. and Leptochloa spp. with different modes of action, mainly at the target site. With this project, we intend to complement the previous study by studying the distribution of resistance in rice fields in Spain, monitoring and to deepen the mechanisms of resistance found in the different cases; these mechanisms will be related to the response to different herbicides (studying possible cross-resistance / multiple) to design specific prevention and control strategies with the tools currently available (herbicides with different modes of action, cultivation, such as dry planting, resistant varieties or other non-chemical control tools).

It is essential to develop rapid resistance confirmation techniques using PCR in order to make alternative control proposals faster and more effectively in real time. In addition, this project will correlate the results found in Spain with neighboring countries where rice is grown in the Mediterranean region such as France, Italy and Portugal.