Common broadleaf weeds present at experimental sites during
the 3-year period included R. dentatus, Medicago polymorpha L.,
C. album, and Anagallis arvensis L. A significant treatment by year
interaction (P < 0.05) was observed for weed density and biomass;
therefore, data of all three years were presented separately. There
was no difference in broadleaf weed density among barley cultivars
in 2007 and 2008 (Table 1), but variable result was observed in
2009 (Fig. 1). The exact reason for this variable response is
unknown, but it might be because of the fact that barley cultivars
can vary in their competitiveness with weeds. For example, density
of A. arvensiswas significantly higher (6.7 plantsm2) in DWRUB 52
compared to other two cultivars with the lowest density (3.0 plants