International Journal of Weed Science and Technology (IJWST) ISSN 4825-3499, Vol. 4(1), pp. 084-092, August, 2021. © Advanced Scholars Journals

Full length Research paper

Evaluation of various methods and their combinations for Weed control in Onion (allium cepa l.) in the central rift Valley of Ethiopia

Feyisa Bekele and Ferdu Azerefegne*

Department of Plant Science, College of Agriculture, Raya University

*PO Box 770, School of Plant and Horticultural Sciences, College of Agriculture, Hawassa University

*Corresponding author: Email:[email protected]

Accepted 28 March, 2021.

Abstract 

The study was initiated with evaluating the effect of Pendimethalin and Oxyflourfen herbicides with or without supplement of different hand weeding time for control of weeds in onion in the Central Rift Valley of Ethiopia during 2017/2018 under irrigation. The experiment was contained 13 treatments and laid out in randomized complete block design with four replicates. Collected data were analyzed using Statistical Analysis Software version 9.0. The weed density varied significantly with the treatments (P<0.05). At 60 Day after transplanting the lowest weed density (41.875/m²) was recorded under Hand weeding three week after transplanting followed by Oxyflourfen at 0.5L/ha + Hand weeding six week after transplanting At harvest the lowest weed density (30.875g/m²) was obtained under Oxyflourfen at 0.5L/ha+Hand weeding six week after transplanting. The lowest weed dry weight was recorded from plot treated with Pendimethalin at 1.5L/ha+Hand weeding nine week after transplanting (293.27g/m²). The highest weed control efficiency (82.15%) was recorded under Pendimethalin at 1.5L/ha+Hand weeding nine week after transplanting followed by Oxyflourfen at 0.5L/ha+Hand weeding nine week after transplanting (80.48%) after weed free plot.The maximum plant height (43.47cm) was recorded in weed free plot followed by Oxyflourfen at 0.5L/ha+Hand weeding three week after transplanting (40.68cm). Maximum bulb diameter, bulb weight, bulb size (3.51cm, 122.58g, 73.25ml, 29.62ton/ha) were recorded respectively from weed free plot, which were statistically non-significant from Oxyflourfen at 0.5L/ha+Hand weeding nine week after transplanting. The lowest loss in yield (0.03%) was recorded in weed free check followed by plot treated with oxyflourfen at rate of the 0.5 L/ha + Hand weeding six week after transplanting (6.8%) as compared to the highest yield obtained in plot treated with oxyflourfen at rate of the 0.5 L/ha + Hand weeding nine week after transplanting. Weed free check plot resulted in higher cost of protection and gross return but lower in net return and benefit: Cost ratio, whereas Oxyflourfen at 0.5L/ha and pendimethalin at 1.5L/ha showed highest Benefit: Cost ratio (20.34 and 14.65) respectively. The study showed that using herbicides alone or in combination with hand weeding is highly profitable than using hand weeding alone.

Keywords: Effect, Evaluation, Herbicides, Hand weeding, Onion, Weed control