Document Type : Research Article
To evaluate the effects of water quality and adjuvant (ammonium sulfate) in glyphosate herbicide efficacy on dry matter reducing of weeds in a barberry garden, a factorial experiment based on RCBD with three replications was carried out at Research Garden of Faculty of Agriculture, University of Birjand in 2010. Experimental factors were water different quality in two levels medium hard with 2950 ppm and hard water with 4774 ppm total soluble concentration) with soft water, glyphosate (roundup) dose in four levels including 2, 4, 6 and 8 lit.ha-1 and using and not using the additive (ammonium sulfate at 6 kg.ha-1). The results showed that raising herbicide dose increased the control percentage of weeds. Application soft water with herbicide had the most control percent and showed significant differences with other waters, So that the most and the lowest control percents was belong to soft water with glyphosate dose of 8 lit.ha-1 and hard water with glyphosate dose of 2 lit.ha-1, respectively. In addition the results showed that application ammonium sulfate with hard water on control percentage had significant .but had more effect on broad leaves species comparing with narrow leaves. Totally the effect of different factors on control percent increased over the time.