Determination the phenology and using Geographic Information System (GIS) for management winter wild oat (Avena ludoviciana) in wheat fields

For managing the winter wild oat in wheat fields, four field experiments were conducted in four regions of Iran: Zanjan, Karaj, Varamin and Amol during 2006 and 2007. The predictive weed management maps were produced for Mazandaran province using Geographic Information System (GIS). The results showed that despite high variation in phenological stages during growing season at different sites of experiments, these stages were relatively similar when evaluated based on degree days. The starting and terminating time for application of post emergence herbicides for control of winter wild oat in wheat fields were determined 400 and 1000 GDD, respectively. Using prediction map that produced by GIS, the suitable time for starting and terminating post emergence chemical control (post emergence) and the suitable time for nitrogen fertilizer application in order to reduce competitive ability of winter wild oat against wheat in different regions of Mazandaran province could be determined.