Investigation on 12 spring barley and 7 oat genotypes under organic growing system during 2007-2008 revealed that mean yield of oats was 3.3 t ha -1, whereas barley yielded on average 2.3 t ha -1. Also, oats were found to be more resistant to leaf diseases. Oats were severely infected by leaf rust in 2007, but the disease did not correlate ( r=-0.17) with yield. The majority of barley genotypes were infected with powdery mildew in both years and with leaf spotting diseases in 2007. Leaf spotting diseases negatively influenced ( r=-0.53*) yield. Oats possessing higher vegetative growth rate, higher plant height, large and prostrate leaves, and larger stems were superior to barley by canopy traits during the growing season.
