Assessing the opportunity for site-specific management of Avena sterilis in winter barley fields in Spain

Abstract

The abundance of Avena sterilis in dryland barley fields was studied in four Spanish provinces. During two growing seasons, differential geopositioning system (DGPS)-geo-referenced A. sterilis infestations were obtained in 31 fields. The majority of the infestations were concentrated in few large but irregularly shaped patches, with a higher number of smaller and more regular patches accounting for a small proportion of the infestation. A multitude of very small and irregular patches completed the inventory. The implications of this spatial structure were studied. Site-specific adjusted-dose herbicide application offered 61-74% potential herbicide savings. However, given the low levels of infestation and the low economic returns obtained in most of the provinces, the most profitable strategy was generally no herbicide application. Site-specific treatments were advantageous only in high-returns systems. Because few large patches provided the majority of the infestation, zone-specific treatments would be advisable, until such time that weed detection and site-specific application technologies become more efficient. © 2006 The Authors.