Weed flora survey in field crops of Northwestern Ethiopia

A survey was conducted in different field crops of six districts (Chilga, Gondarzuria, Metema, Takussa, Dabat and Dembia) in Northwestern Ethiopia within 2016 and 2017 cropping seasons. The objective of the study was to identify the most important weed species and to determine their frequency, density and uniformity at different altitudes. A quantitative and qualitative method was employed for the enumeration and identification of weed species. Quadrats were laid along transects and individual weed species in each quadrat was identified and counted. Frequency, uniformity, similarity index and relative abundance were used to determine the weed community structure. A total of 76 weed species belonging to 65 genera within 27 families were identified across different field crops. The most dominant families, based on the family dominance index (FDI), were Asteraceae, Poaceae, and Fabaceae with 78.97, 63.76, and 20.72 FDI, respectively. The most frequent, abundant and dominant weed species were Digitaria abyssinica (Hochst. Ex A. Rich), Cyperus rotundus L. and Cynodon dactylon L. The average values for frequency and dominance of weed species in arable fields ranged between 49.34 to 59.87% and 3 to 3.69%, respectively. Results obtained from this study would be useful in creating a weed management programme and making inform decision on choice of herbicides and directing research toward new or improved weed control measures. Key words: Altitude, density, district, dominance, family, frequency, species.