Maize (corn) monocultures are a common sight on Hungary’s Northern Great Plain. But as with any monoculture herbicide resistance is always a potential danger. In 2010 Istvan Szolomajer discovered Panicum riparium growing on his fields. Initially, Istvan and his fellow farmers used ALS inhibitors to control this weed, but after several years of application, there was strong evidence of an emerging resistance problem. Istvan’s solution to the resistance problem was to replace maize monoculture with crop diversity – changing from monocot to dicot crops and from spring to winter crops, for example. This year, he has been growing sunflowers on 100 ha, winter wheat on 50 ha, and maize on most of the remaining 200 ha under cultivation. This crop diversity has brought Istvan welcome relief from resistant Panicum riparium. Close cooperation with Bayer staff in Hungary has been a crucial factor in Istvan’s diversity strategy.