Iranian Society of Weed Science Iranian Journal of Weed Science 1735-3548 11 1 2015 08 23 Predicting Seedling Emergence of Different Wild Oat (Avena ludoviciana) Predicting Seedling Emergence of Different Wild Oat (Avena ludoviciana) 91 104 19810 FA Journal Article 2016 05 18 Wild oat is an economically important annual weed throughout small grains production areas. Timely and more accurate control of wild oat may be developed if there is a better understanding of its emergence patterns. Sixwild oat populations, collected from different climate regions, were sown in agricultural reaserch field of University of Tehran located at Karaj, Iran during 2012-2013 growing season. The experimental design was a randomized complete blocks with factorial arrangement of treatments in three replications. Wild oat populations were collected from Ahvaz, Karaj, Kamyaran, Ghazvin, Shiraz and Isfahan. Seedling emergence pattern was surveyed under rain fed and irrigated conditions. Rusults indicated that seedlings emergence were started in 306 growing degrees day (GDD) Less GDD was needed for irrigated (461-482) compared with rain fed conditions (546-665 GDD) to reach 50% emergence. There was no difference of GDD to reach 50% emergence, in Ghazvin and Ahvaz populations under the two moisture conditions. Among wild oat populations, Ahvaz needed maximum growing degree days to reach 50% emergence, receiving 784 and 755 GDD under rainfed and irrigated conditions, respectively. Overall, the results showed that wild oat emergence could be predicted based on growing degree days from soil temperature. This approach can help to provide appropriate time of wild oat control.  Wild oat is an economically important annual weed throughout small grains production areas. Timely and more accurate control of wild oat may be developed if there is a better understanding of its emergence patterns. Sixwild oat populations, collected from different climate regions, were sown in agricultural reaserch field of University of Tehran located at Karaj, Iran during 2012-2013 growing season. The experimental design was a randomized complete blocks with factorial arrangement of treatments in three replications. Wild oat populations were collected from Ahvaz, Karaj, Kamyaran, Ghazvin, Shiraz and Isfahan. Seedling emergence pattern was surveyed under rain fed and irrigated conditions. Rusults indicated that seedlings emergence were started in 306 growing degrees day (GDD) Less GDD was needed for irrigated (461-482) compared with rain fed conditions (546-665 GDD) to reach 50% emergence. There was no difference of GDD to reach 50% emergence, in Ghazvin and Ahvaz populations under the two moisture conditions. Among wild oat populations, Ahvaz needed maximum growing degree days to reach 50% emergence, receiving 784 and 755 GDD under rainfed and irrigated conditions, respectively. Overall, the results showed that wild oat emergence could be predicted based on growing degree days from soil temperature. This approach can help to provide appropriate time of wild oat control.  https://ijws.areeo.ac.ir/article_19810_cedbd0a05001121a5e3b52fa088998d3.pdf