Assessment and Identification of Major Weeds on Maize (<i>Zea mays</i>) in East Shewa and West Arsi, Zones, Oromia

Major cereals globally include wheat, maize, and rice, contributing 80% of production. In Ethiopia, key cereals are tef, maize, wheat, barley, sorghum, rice, and finger millet. Maize accounts for 27.02% of annual grain production, followed by tef at 17.29%. Maize yields the highest per unit area at 3.7 t/ha, followed by rice and wheat. Ethiopia's mean national wheat yield is 2600.75 kg/ha, below African and global averages. Yield-reducing factors include soil fertility decline, weeds, diseases, and insects. Weeds significantly constrain cereal crop production and are crucial for yield increase. Weeds compete for resources, negatively impacting crop yield and increasing production costs. Weeds contribute to 45% of annual agricultural product losses globally. Crop yield losses due to weeds in Africa range from 50% to 100% for various crops. Limited studies exist on common weeds affecting Maize at the West Arsi and East shewa. The weed survey was conducted in East Shewa and West Arsi zones, Oromia. Assessment took place during the main cropping seasons of 2021-2023. The survey covered seven districts: ATJK, Dugda, Bora, Lume, Negelle Arsi, Shashemanne, and Kofele. Maize fields in 37 kebeles and 107 fields were included in the survey. Key parameters such as density, frequency, relative frequency and similarity index have been analyzed for each crop. Generally, for most crops and districts, annual broad leaf weeds dominated over grass and sedge type of weeds. The most dominant family that contained the highest number of weed species for all crops and fields assessed was Asteracae followed by Poaceace and Amaranthaceae 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 fields ranged from 1% up to 91% while the dominance value ranged from 0.71% up to 21.92%. The most frequent and dominant weeds were Galensoga palviflora and Argemone mexicana L., Maize crop.