International Journal of Weed Science and Technology (IJWST) ISSN 4825-3499, Vol. 5(1), pp. 093-100, March, 2022.  Advanced Scholars Journals

Full length Research paper

Quantitative assessment of weeds in Onion fields: in case of central rift valley of Ethiopia.

Feyisa Bekele and Ferdu Azerefegne*

Department of Plant Science, College of Agriculture, Raya University

*P.O. Box 770, School of Plant and Horticultural Sciences, College of Agriculture, Hawassa University

*Corresponding author: Email:[email protected]

Accepted 28 July, 2021.

Abstract

Weed population survey were carried out in 200 onion fields of Central Rift Valley of Ethiopia, during 2017/2018 cropping seasons to determine weed species composition, prevalence and distribution. Weed species compositions were determined using a quadrant of 0.5m x 0.5m through systematic sampling technique of inverted W method to obtain representative samples in the field. The individual weed species were analyzed using quantitative means. A total of 43 weed taxa belonging to 16 families were recorded. According to number of species recorded Asteraceae which comprised 16 species, Poaceae10 species, Solonaceae and Cyperaceae 2speciesranks the 1^st, 2^nd, 3^rd abundant weed families respectively. In Adami Tulu woreda: The frequency ranged from 4 to 96%. Argemone Mexicana was the most frequent (96%) and followed by Nicandraphysaloides, Portulacaoleraceae, Cyperusrotundus and Amaranthushybridus. The dominance range in this location was 0.19 to 19% and Portulacaoleraceae, accounted 19.52% of the species which was followed by Cyperusrotundus, Nicandraphysaloides, Amaranthushybridus and Argemone Mexicana. In Dugdaworeda: The frequency of individual weed species ranged from 20 to 96%. Nicandraphysaloides was the most frequent (96%) and followed by Galinsogaparviflora, Amaranthushybridus and Cyperusrotundus. Dominance value ranged from 0.68 to 17.30%. Portulacaoleraceae contribute 17.3% followed by Cyperusrotundus, Chenopodium album, Galinsogaparviflora and Nicandraphysaloides. In Lumeworeda: Portulacaoleraceae was the most frequent (88%) and followed by Galinsogaparviflora, Eleusineindica and Tagetesminuta. The dominance range in this location was 0.17 to 12.08%. Cyperusrotundus account12.08% and followed by Portulacaoleraceae, Commelinabenghalensis, Galinsogaparviflora, Amaranthushybridus and Argemone Mexicana. In around Adama: The frequency range from 6 to 96%. Both Tagetesminuta and Echnochloacolona were the most frequent (96%) and followed by Polygonumnepalense, Galinsogaparviflora, Eleucineindica and Bidenspilosa. Their dominance level ranged from 0.15 to 11.14%. Echinochloacolona accounted 11.14% and followed Bidenspilosa, Tagetesminuta and Amaranthushybridus. Survey of weed flora composition in each location showed some variation infrequency, abundance and dominance of some weed species But in most cases all woradas have similar weed communities (SI>60%). Thus, the frequent, abundant and dominant weeds of all locations and weed flora composition should be considered while devising management strategies.

Keywords: Amaranthushybridus, Argemone Mexicana, Cyperusrotundus, Nicandraphysaloides, Galinsogaparviflora, Portulacaoleraceae