Survey and Identification of Major Weeds of Seeds Spice in Ethiopia

In Ethiopia coriander (Coriandrum sativum L.), fenugreek (Trigonella foenum-graecum) and black cumin (Nigella sativa L.) are economically important seeds spices in the family of Apiaceae, Fabaceae and Apiaceae (Umbelliferae), respectively. They are highly suffering due to weed infestation especially competing for water and nutrient. However, before estimating yield losses due to weeds and devising weed control strategies, identification and quantification of weeds are very important. The weed survey was conducted in East showa, Arsi, Bale, North wollo and North Gondar zones during 2016 and 2018 in main cropping seasons to identify most common and prevalent weeds associated with seeds spice (coriander, fenugreek and black cumin). Weed species characteristics, density, frequency, relative density, relative frequency, summed dominant ratio over locations and seasons were calculated. The result shows that a total of 22, 37 and 21 weed species were identified in coriander, fenugreek and black cumin fields, respectively. The most important families according to the number of represented species were Amaranthaceae, Caryophyllaceae, Primulaceae and Fabaceae in coriander, Amaranthaceae, Fabaceae and Polygonaceae in fenugreek and Chlorideae and Scrophulariaceae in black cumin fields. The frequency of individual weed species in coriander, fenugreek and black cumin field ranged from 0.14% up to 1%, 0.13% up to 1% and 0.25% up to 5% while the dominance value ranged from 0.14 up to 49.1%, 0.25 up to 26.5% and 0.25 up to 4.5%, respectively. The most frequent and dominant weed was Chenopodium album in coriander field whereas, the most frequent weed was Chenopodium album and the most dominant weed was Drymaria cordata in fenugreek field. In black cumin field Cynadon dactylon and Solanum nigrum are most dominat and the most frequent weeds respectively. This survey has ranked the most abundant and troublesome weed species in coriander, fenugreek and black cumin growing areas of Ethiopia. Therefore this information is vital for setting research and developmental work priorities concerning coriander, fenugreek and black cumin weeds of the study area