Assessment of Major Weeds for Cereals Crops in Buno Bedele and Ilu Aba Bor Zones of South-western Oromia, Ethiopia

Field survey was conducted to assess weeds of three major cereal crops i.e maize, sorghum, and Tef in representative districts of Ilu Aba Bora and Buno Bedele Zones of Southwestern Oromia. Key parameters such as frequency, dominance, abundance and similarity index have been analyzed for each crop and district. Generally, for most crops and districts, annual broad-leaf weeds dominated over grass, sedge and leafless type of weeds. The most dominant weed family that contained the highest number of weed species for all crops and fields assessed was <i>Poaceae</i> followed by <i>Asteraceae</i>, <i>Compositeae</i> and <i>Caryophyllaceae</i> families. In most cases, weeds of a crop were similar across the various districts as indicated by similarity index. The frequency of individual weed species in maize, sorghum, and tef fields ranged from 3.3% up to 100%, 6.7% up to 100% and 3.3% up to 100% respectively in the Buno Bedele zone and 3.3%-100% in maize, sorghum and tef respectively in Ilu Aba Bor zone while the dominance value ranged from 0.4% up to 24.7%, 0.5% up to 13.2% and 0.1% up to 14.8% respectively in Buno Bedele zone and 0.5% up to 26.3%, 0.2% up to 20.8% and 0.2 up to 25.4% in maize, sorghum and tef respectively in Ilu Aba Bor zone. The most frequent and dominant weed species were <i>Galinsoga parviflor, Polygonum nepalense, Bidens pachyouma, Guzotia scabra</i> (Vis.) Chiov., <i>Trifolium pretense and Datura stramonium</i> L. for both Maize and Sorghum; <i>Spergula arvensis</i> L., <i>Setaria pumila, Galinsoga parviflor, Polygonum nepalense, Cyperus esculentus</i> L., <i>Centella asiatica </i>L. <i>Trifolium pratense</i> and <i>Bidens pachyouma</i> for Tef crop.