PERFORMANCE, VARIANCE COMPONENTS AND HERITABILITY OF OATS CULTIVERS UNDER IRRIGATION INTERVALS

Seeds of five cultivars of oats (Avena sativa) were introduced from Italy in 2009. Seeds were propagated on the farm of the Dept. of Field Crops Sci. / Coll. of Agric. / Univ. of Baghdad in the season 2009 - 2010. The cultivars Anatolia, Alguda, Hamel, Pimula and Genzania were planted under 3 irrigation intervals; 3, 4 and 5 weeks to give water depth of 480, 400 and 320 mm, respectively . The depth of water was 80 mm each irrigation. A factorial experiment with RCBD of 4 replicates was conducted in 2 consecutive seasons in 2010 - 2011 and 2011 - 2012. The cultivar Alguda gave highest grain yield (8.07 t/ ha) under 480 mm, and 7.02 t / ha average of 3 water depths. This cultivar was characterized by high growth rate (13.2 g/m(2)/d) that increased number of grains in unit area (24300 k/m(2)) , and accordingly higher grain yield . The 3 depths of irrigation; 320, 400, and 480 mm gave mean grain yield of 5.51, 5.97, and 6.13 t/ ha, respectively without significant differences . Genetic variance for most of traits studied was much higher than environmental variance, especially for days to 95% physiologic maturity, which gave a ratio of delta(2)g / delta(2)e around 5200%! . The traits; number of kernels, number of tillers, and number of racemes / m(2) , kernel filling period, day to 95% booting and physiologic maturity, harvest index and crop growth rate were of high genetic variance. Thus, it was concluded that these traits were of higher contribution to high grain yield, so, we recommend using these traits in next programs of testing oats a for a biotic stress tolerance. More care should be given to better plot leveling to reduce depth of irrigation to less than 80 mm, especially on Alguda and Anatolia cultivars for their high grain yield and stability.