The efficacy of different water volume and nozzle systems, comprising spinning-discs with two disc speeds (low volume, LV), a spinning-cage rotary atomizer (median volume, MV), a flat fan nozzle Teejet-11004 (high volume, HV), and no weed control, were assessed for the application of 2,4-D to control weeds in irrigated wheat. The herbicide was applied at the tillering stage of cultivated wheat, Ghods variety. Sprayer nozzle performance was evaluated in terms of wheat grain yield, weed shoot biomass, and wheat residual (straw), at the research farm of Shahrekord University in 2007 and 2008. ANOVA analysis indicated that nozzle type, and the year had significant effects on grain yield and dry biomass of weeds at 5% confidence. There was a significant difference be- tween the two years of the experiment for all variants. The results indicated that the median diameter volume using the spinning disc (low disc speed) for herbicide application, gave better weed control than others. The spinning disc nozzle decreased water use and so it was cheaper to operate. It did not, however, significantly improve herbicide efficacy, especially in dense canopies compared with the conventional flat fan nozzles. The spinning-disc had more droplet uniformity at high disc speeds compared with the cage rotary atomizer, but was more effective for weed control at low disc speeds.