Weed Survey System used in Saskatchewan for Cereal and Oilseed Crops

Abstract

A weed survey system methodology was developed and used annually for 4 yr in the province of Saskatchewan. Based on a stratified random sampling procedure, fields were selected in wheat (Triticum aestivumL.), barley (Hordeum vulgareL.), oat (Avena sativaL.), rye (Secale cerealeL.), rape (Brassica napusL.,Brassica campestrisL.), and flax (Linum usitatissimumL.) crops. The boundaries of the 43 agricultural extension districts in the province formed the strata. The provincial agricultural extension service provided staff to conduct the survey. Computer processing of the data enabled reports, containing summary tables and distribution maps, to be distributed to extension, research, and industry personnel within 3 months after completion of the field survey. The field surveys were conducted late in the growing season before harvest commenced; hence, the weed populations consisted of species that had been present during the early part of the growing season and may have contributed to yield losses. During the 4 yr of the survey, weeds were counted in 4423 fields. Of the 164 species recorded, 97 species occurred in more than three fields. Only 29 species were encountered frequently in the fields. Green foxtail [Setaria viridis(L.) Beauv. # SETVI), wild buckwheat (Polygonum convolvulusL. # POLCO), and wild oat (Avena fatuaL. # AVEFA) were the top three species based on a ranking system using a measure called relative abundance.