Weed species composition and abundance in the main coffee production systems and regions of Ethiopia

A weed population survey was carried out to assess the variability in weed species composition and abundance in the main coffee production systems and regions of Ethiopia. A total of 168 coffee fields were assessed using a quadrat count in a systematic sampling technique. Weed species composition was evaluated using frequency, abundance and dominance of species at each site. We found a total of 98 weed taxa belonging to 35 families, of which Asteraceae and Poaceae were the most abundant. The most frequent weed species were Oplismenus hirtellus (L.) P.Beauv., Galinsoga parviflora Cav., Achyranthes bidentata Blume, Impatiens balfourii Hook. F., Bidens pilosa L. and Commelina benghalensis L., with a frequency of over 40%. The density of weed species varied and the highest abundance value was recorded by O. hirtellus. Similarity indices of the 16 districts assessed ranged from 8.33% to 72.73%, while the similarity indices of the coffee production systems and altitudinal range ranged from 7.14% to 49.49% and 41.76% to 68.75%, respectively. Coffee production systems and soil properties were the main explanatory variables influencing weed species distribution and composition in the study areas. In conclusion, coffee producers should take into account these variables while designing the appropriate management strategies to curtail weeds in coffee farms.