Flora and Distribution of Weeds in Wheat, Tomato, Sugar Beet, Onion and Chickpea Fields in Mashhad Region

Weed flora identification in the fields dramaticaly helps to you decide about weed management operations. Weed flora characteristics in the fields of wheat, tomato, sugarbeet, onion and chickpea were investigated by method of random sampling on a area near research farm in the Ferdowsi University of Mashhad, Iran in 2007. In this experiment, five weed sampling includings 7, 14, 21, 60 and 67 days after crop emergence were conducted. All weeds in 0.25 m2 samples from 10 points according to “W” method were identified and the weed species found in all samples counted. Nineteen weed species were identified from the beginning to the middle of the growing season in these fields. Field bindweed, prostrate knotweed, common fumitory, prostrate pigweed, redroot pigweed, black nightshade, common lambsquarters and barnyardgrass were the most common weeds. Field bindweed, prostrate knotweed, common lambsquarters and barnyardgrass had the highest level of distribution uniformity in these crops. Common cocklebur, green foxtail, London rocket, wild mustard and shepherds purse reached to high densities in wheat. The lowest and the highest weed densities were observed in the tomato and sugarbeet fields, respectively. Weed species richness was less than the other crops in onion and chickpea fields. Common lambsquarters and prostrate knotweed were dominant species in these field crops.