Assessment on the distribution and importance of weeds in wheat, and farmers weed management practices at Chelia and Midakegn Districts, West Shoa Zone, Oromiya National Regional State-Ethiopia was made during August to September, 2012 main cropping season to identify, point out and prioritize problematic weeds and to determine impacts of weeds in small scale farmers’ fields. The frequency, abundancy and dominance for each species were calculated. For socio-economic study, purposively and systematically 218 farmers were interviewed regarding different aspects of weeds and weed management practices adopted in wheat fields of the study area, and have been documented as farmer’s indigenes knowledge. The result revealed 93 weed species belonging to 33 families and 75 genera as weeds of wheat. The 10 major families based on number of taxa were: Poaceae (16), Asteraceae (14), five species each under Papilionaceae and Cyperaceae, three species each under Boraginaceae, Chenopodaceae, Commelinaceae, Convolvulaceae, Polygonaceae and Solanaceae, and they contain 65% of the total weed flora. The most frequent, abundant and dominant weed species were found to be Polygonum nepalense, Pennisetum clandestinum, Cynodon dactylon, Plantago lanceolata, Hygrophilla auriculata, Galinsoga parviflora,Veronica filiformis, Cyperus rotundus, Spergula arvensis, Galium spurium, Trifolium pretense and Euphorbia hirta. Greater than 60% similarity index values of weed communities across all sampled locations were registered. Most of the farmers understand that weeds are the most important silent constraint on wheat production. They were found adopting different possible weed control measures to minimize the negative effect of weeds. However, the assessment work realized that no effective and sustainable weed control technology at their hand attracting future research effort to develop proper wheat weed management practices for the area.

Keywords: Distribution, Districts, Farmers Practice, Importance, Weeds, Wheat Field