Reduction of yellow nutsedge infestation levels in highly infested fields: Continuous maize cropping as potential control strategy

Yellow nutsedge (Cyperus esculentus L.) is among the most dreaded weeds worldwide. In Switzerland, it has increasingly become a problem for vegetable growers and arable farmers. This weed propagates and disperses via vegetative tubers in the soil. Producers are facing an important challenge: They have not only to stop the weed’s further dispersal but also reduce infestation levels in fields already broadly infested with yellow nutsedge. For the later a promising strategy is continuous cropping of maize combined with intensive weed control. Field trials were carried out in maize during 3 years (2011–2013). Aims were to determine the efficacy of different herbicides, split application, and mechanical control against yellow nutsedge. The results clearly showed that split application was superior to single application. S-metolachlor, bentazone, and rimsulfuron combined with mesotrione showed high efficacy. S-metolachlor combined with hoeing passes reduced infestation levels. A late under-leaf application additionally reduced yellow nutsedge. Cropping maize with the aim to reduce yellow nutsedge infestation levels requires a very intense weed control that will exceed current intensity levels considerably.