effect of haloxi phop-r- metyl ester doses in different grass weeds growing stages in safflower

a field study was conducted to evaluate the effect of haloxyfop-r-methyl ester doses in different grass weeds in various growing stages in safflower during 2011-2012 growing season in research farm of college of agriculture, shiraz university. the study was carried our as split split plot based on randomized complete block design with three replicates. the main factor, sub factor and sub sub factor were supergalant (doses: 0.6, 0.8 and 1.0 l ha-1), adjuvant use (with or without adjuvant) and time of herbicide application (2 leaf, 6 leaf, tillering stages of grass weed) respectively. the treatment efficiency in weeds control was examined with generalized liner methods and introducing precise frequency after 2, 4 and 6 weeks. the results showed that the highest herbicide efficiency and the lowest weed dry weight were achieved in 1 l ha-1 supergalant with adjuvant at 2 leaf stage of grass weed. adjuvant use could reduce weed density by 74% as compared to no adjuvant use treatments. the results also showed that adjuvant use increased weed control at all herbicide doses, and there were no significant difference between weed dry weight reduction in lower dose of herbicide with adjuvant and higher dose of herbicide without adjuvant treatments. application of supergalant at the rate of 1 l ha-1 with adjuvant in 2 leaf stage of weed caused 87% reduction in grass weed density, which did not differ significantly with 0.8 l ha-1 dose.