Quantitative Determination of Weed Occurrence on Upland Rice of Bambasi, Ethiopia

Abstract

The weed survey was carried out in 2012 and 2013 cropping season on eight to ten upland rice farmers’ fields respectively in Bambasi, Ethiopia to determine weed prevalence, species composition and distribution. A quadrant size of 0.25 m2 were used in a systematic sampling technique and a total of 21 weed species belonging to 12 families were identified and counted. The most dominant weed family based on the number of species recorded was poaceae (grasses) which comprized 5 species. during both cropping season survey, most (66.67 %) of the species were broad leaved herbaceous plant. weed species composition was analyzed using quantitative means and most frequent weed species in upland rice field during 2012 cropping season was cyprus rotondus (100%) followed by Ageranthum conizoid, Commelina subulata, Digitaria abisynica, Elusin indica and Leucas martinicensis. The dominance range during this year was 0.09 to 54.59% and Ageranthum conizoid accounted 54.59% of the species which was followed by Cyprus rotondus, Spergula arvensis and Commelina subulata. during 2013 cropping season Ageranthum conizoid and Polygonum nepalense were the most frequently (100%) occurred weed species followed by Cyprus rotondus, Commelina subulata, Digitaria scalarum, Elusina indica, Galensoga parviflora. The dominant weed species during this year (2013) was Polygonum nepalense (20%) followed by Ageranthum conizoid and Cyprus rotondus, Commelina subulata and Leucas martinicensis dominance level range between 16.36% and 4.02% respectively. The prevalence and density of most species on upland rice during 2012 and 2013 cropping season was similar. Moreover, similarity index between the 2012 and 2013 surveys were higher (100%). Thus, the weed control and management research strategy should consider the dominant and frequent weed species of both cropping seasons and weed flora composition.