Abstract

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In Ethiopia black pepper (Piper nigrum L.) and cardamom (Elettaria cardamomum M) are economically important spices in the family Piperaceae and Zingiberaceae, respectively. These spices 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 Sheka, Benchmaji and Majang zones during 2008 to 2009 in both spring ‘Belg’ and summer (Meher’) seasons. Weed species characteristics, average frequency and dominance over locations and seasons were calculated. The result shows that a total of 25 and 22 weed species were identified in black pepper and cardamom fields, respectively. The most important families according to the number of represented species were Poaceae, Malvaceae, Asterace, Amaranthaceae and Cyperaceae in black pepper, and Poaceae and Asterace in cardamom fields. The frequency of individual weed species in black pepper and cardamom field ranged from 1% up to 67% and 3% up to 55% while the dominance value ranged from 0.09 up to 24% and 0.01 up to 85%, respectively. The most frequent and dominant weed was Commelina benghalensis in black pepper field whereas, the most frequent weed was Galinsoga parviflora and the most dominant weed was Cerastium arvense in cardamom field. There were a positive and significant relationship among weed species frequency, abundance and dominance (P<0.01). This survey has ranked the most abundant and troublesome weed species in Black pepper and cardamom growing area of south west Ethiopia. This information is vital for setting research and developmental work priorities concerning Black pepper and cardamom weeds of the study area.

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