Recognition, determination of density and phenology of dominant weeds in East Azerbaijan canola fields

Identification of weeds in agricultural crops is a fundemental action in weed control combinational management. The aim of the weed control management is to change the relationship between crops and weeds in benefit of cultivar. By recognition of particular weeds in cultivation, correct and on time control decisions can be made. So, in order to determine the combination, density and phenology of weeds, fall and spring Canola fields of province were studied for two years starting from 2002, from a week after planting to the end of seeding. Fields were selected randomly and they were systematically sampled by ʹWʹ sampling pattern. As a result, 42 weeds were recognized and relative density was calculated for Poaceae, Brassicaceae and other dicotyledons. Dominant dicotyledonous weeds in studied towns were as follows: Raphanus raphanistrum L., Chenopodium album L. Rapistrum rugosum (L.) All Galium tricorne with. Sisymbrium irio L., Heliotropium eichwaldi Steud. Salsola kali L. and Papaver decaisnei Hochst.et.Steud respectively. The Fear highest relative densities were reported in Jolfa, Marand, Shabestar and Ahar by 92, 59, 51 and 62 percent belonging to other dicotyledonous groups. In Tabriz and Bonab, they were reported as 61, 70 and 36 percent belonging to Brassicaceae group. Relative density means for three groups was 10.86 in poaceae, 37.71% in Brssicaceae and 49.86% in other dicotyledons.