Effect of weed management methods on weeds and wheat (Triticum aestivum L.) yield

Abstract

An experiment was conducted at Holetta Agricultural Research Center to study the effect of weed management practices on weeds and yield of wheat (Triticum aestivum L.) during 2010 to 2011 crop seasons in randomized complete block design with three replications. The experiment comprised of twelve weed management practices as treatments. The crop was infested with Avena fatua L. Cynodon dactlylon (L) Pers, Digitaria abbisinica (A. Rich) Stapt and Phalaris paradoxa L. among grass weeds and Amaranthus spinosus L., Caylusea abyssinica (Feresen.) fisch and May, C. trigyna L., Conolvulus arvenesis L., Chenopodium album L., Chenopodom nobile L., Corrigoala capensis Willd., Galinsoga parviflora Cov. Guizotia scabra (Vis.) Chiov., Medicago polymorpha L., Oxalis latifolia H.B.K., Polygonum nepalense L., Plantago lanceolata L., Raphanus raphanistrum L., Spergula arvensis L. and Tagetes minuta L. were among broad leaf weeds. The results showed that broadleaved, grass and total weed density as well as dry weight were significantly influenced by weed management practices. Hand weeding + 15 cm row spacing followed isoproturon at 1.5 kg ha-1 + 15 cm row spacing significantly reduced density and dry weight of weeds. Among herbicides, isoproturon + 15 cm row spacing provided better control of broadleaved and total weeds, whereas; clodinafop-propargyl + 15 cm row spacing proved better than isoproturon at 1.50 kg ha-1and hand weeding + 15 cm row spacing in controlling grass weeds. Highest grain yield (2289.4 kg ha-1) in was recorded in hand weeding + 15 cm row spacing followed by isoproturon at 1.50 kg ha-1 + 15 cm row spacing (2177.3 kg ha-1). Maximum N uptake was also recorded in these treatments. Uncontrolled weed growth throughout the crop growth caused a yield reduction 57.6 to 73.2%. Post emergence herbicides (isoproturon at 1.50 kg/ha) and /or hand weeding and hoeing at tillering + narrow spacing (15 cm) can further enhance the weed suppressive effect of the crop. Key words: Wheat, weeds, weed management methods, yield loss.