QUANTITATIVE EVALUATION OF PREDOMINANCE OF WEEDS IN WINTER WHEAT (Triticum aestivum L.) AND BARLEY (Hordeum vulgare L.) FIELDS IN EASTERN AZERBAIJAN IRAN

In order to determine the density and abundance of dominant weeds in the Eastern Azerbaijan province of Iran, a total of 93 fields, consisting of 73 winter wheat (Triticum aestivum L.) and 20 winter barley (Hordeum vulgare L.) fields were studied. Field products were sampled from stem (mid-spring) until the end of fruiting in different regions of the province. Weeds were counted and identified according to genus and species, and their stage of development was registered. The entire samplecontained 136 weed species from 100 Genera, belonging to 28 families. The most frequently encountered weeds were members of the Brassicaceae, with 20 species, Poaceae, with 17 species, and Asteraceae, with 16 species. From 136 weed species, the majority (88%) was dicotyledonous, while the remainder was monocotyledonous. Moreover, 78% of the weeds were annual/biennial. The results of this study showed that environmental (such as local climatic and ecological factors) and management factors (such as cultivation) determine the predominance of weed species in wheatand barley fields. Moreover, we demonstrated that proper weed management will substantially help reduce the damage to wheat and barley fields.