University of Kirkuk Kirkuk University Journal for Agricultural Sciences (KUJAS) 2221-0482 7 1 2016 03 01 The interaction effect of locations and seeding rates on yield and its components of some oat (Avena sativa L.) varieties under Rain fed conditions 33 44 123647 10.58928/ku16.07104 EN Abbas M.Al-Hasan Arol M.Anwar Journal Article 2016 03 01 Abstract<br />Afield experiment were conducted in winter season 2011-2012 at three different environmental locations, namely, the koya city /Erbil (570m above sea level and 44°38'E, 36°40' N), Mosul city (223m above sea level and 43°09'E, 36°19' N), and the Alton- koprey/kirkuk (276m above sea level and 44°15'E, 35°73' N) to determine the effect of seeding rates (200 , 300 , 400 , 500 and 600 seed/m2) on yield and its components of Five oat varieties (kangaroo , Mitika , Possum , ICARDA Short and ICARDA Tall). the experiment were conducted by randomized complete Block Design (RCBD) with split-split plot design with three replicates. The interactions between the three studied factors significantly affected the panicles number /m2, grains yield/h, grains filling rate, biological yield and harvest index. All studied characters of oat varieties increased with increasing seeding rates at the three locations expect harvest index of varieties (kangaroo , Mitika , Possum and ICARDA Short) at Alton-koprey location which affected negatively. The highest seed and biological yield for varieties Kangaroo and Mitika were achieved at koya location and seeding rate 600 seed/m2 while the highest seed and biological yield for varieties Possum and ICARDA Short were achieved at the same location with seeding rate 500 seed/m2, at the same location<br />The highest seed and biological yield for variety ICARDA Tall was achieved with seeding rate 400 seed/m2, All varieties in koya location significantly surpassed on mosul location varieties and the variety of last location surpassed on Alton-koprey location varieties. And the negative effect was on characters panicle length , grain number/panicle, seed index ,seed weight /panicle which gives low rates in Alton-koprey location at seeding rate 600 seed/m2. No significant effect for length of grain filling period was shown by increasing the seeding rate for varieties expect Possum variety in koya location. https://kujas.uokirkuk.edu.iq/article_123647_baba7ee2e17b3beb055f3c6ade6c054e.pdf