Observation of Weed Species, Frequency and Density in Common Barley (Hordeum vulgare L.) Fields of Diyarbakir, Turkey: A Case Study

The weed species in the common barley (Hordeum vulgare L.) fields in the Diyarbakir were observed with this study. For this purpose, 50 quadrats of 1m by 1m (1 m-2) were randomly placed and examined at each study site. In every set of the quadrat, frequency and density were observed throughout the cropping season of 2015-2016. During the course of field study 72 weed species belonging to 21 families, 13 grasses, 59 broadleaves were recorded. The common families were Asteraceae and Poaceae in the common barley fields. The encounter frequency of weeds was determined by observing 80% wild mustard (Sinapis arvensis L., 80%), animated oat (Avena sterilis L., 63%), common wild oat (Avena fatua L., 54%), corn buttercup (Ranunculus arvensis L., 54%), corn poppy (Papaver rhoeas L., 52%), creeping thistle (Cirsium arvense (L.) Scop., 51%), volunteer lentils (Lens culinaris Medik., 51%). Wild mustard, which had the highest frequency was also the densest weed species (5.18 plant m-2), and other species such as animated oat (4.33 plant m-2), creeping thistle (1.77 plant m-2), common wild oat (1.72 plant m-2), corn buttercup (1.47 plant m-2), cleavers (1.38 plant m-2), corn poppy (1.22 plant m-2), volunteer lentils (1.07 plant m-2) were important species at all the observed fields. It was observed that the great infestation was shown by broadleaf weeds due to the lack of effective weed control in the barley areas.